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2013
Smidler Andie L, Terenzi Olivier, Soichot Julien, Levashina Elena A, Marois Eric
Targeted Mutagenesis in the Malaria Mosquito Using TALE Nucleases Article de journal
Dans: PLoS One, vol. 8, no. 8, p. e74511, 2013.
Résumé | Liens | BibTeX | Étiquettes: M3i, marois, Mutagenesis, TALEN
@article{AL2013,
title = {Targeted Mutagenesis in the Malaria Mosquito Using TALE Nucleases},
author = {Andie L Smidler and Olivier Terenzi and Julien Soichot and Elena A Levashina and Eric Marois},
url = {http://www.ncbi.nlm.nih.gov/pubmed/23977401},
year = {2013},
date = {2013-08-15},
journal = {PLoS One},
volume = {8},
number = {8},
pages = {e74511},
abstract = {Anopheles gambiae, the main mosquito vector of human malaria, is a challenging organism to manipulate genetically. As a consequence, reverse genetics studies in this disease vector have been largely limited to RNA interference experiments. Here, we report the targeted disruption of the immunity gene TEP1 using transgenic expression of Transcription-Activator Like Effector Nucleases (TALENs), and the isolation of several TEP1 mutant A. gambiae lines. These mutations inhibited protein production and rendered TEP1 mutants hypersusceptible to Plasmodium berghei. The TALEN technology opens up new avenues for genetic analysis in this disease vector and may offer novel biotechnology-based approaches for malaria control.},
keywords = {M3i, marois, Mutagenesis, TALEN},
pubstate = {published},
tppubtype = {article}
}
Anopheles gambiae, the main mosquito vector of human malaria, is a challenging organism to manipulate genetically. As a consequence, reverse genetics studies in this disease vector have been largely limited to RNA interference experiments. Here, we report the targeted disruption of the immunity gene TEP1 using transgenic expression of Transcription-Activator Like Effector Nucleases (TALENs), and the isolation of several TEP1 mutant A. gambiae lines. These mutations inhibited protein production and rendered TEP1 mutants hypersusceptible to Plasmodium berghei. The TALEN technology opens up new avenues for genetic analysis in this disease vector and may offer novel biotechnology-based approaches for malaria control.
Lamacchia Marina, Clayton John Randy, Wang-Sattler R, Steinmetz Lars M, Levashina Elena A, Blandin Stéphanie A
Silencing of Genes and Alleles by RNAi in Anopheles gambiae Article de journal
Dans: Methods Mol Biol., vol. 923, p. 161-76, 2013.
Résumé | BibTeX | Étiquettes: blandin, dsRNA, M3i, RNAi
@article{M2013,
title = {Silencing of Genes and Alleles by RNAi in Anopheles gambiae},
author = {Marina Lamacchia and John Randy Clayton and R Wang-Sattler and Lars M Steinmetz and Elena A Levashina and Stéphanie A Blandin},
year = {2013},
date = {2013-06-13},
journal = {Methods Mol Biol.},
volume = {923},
pages = {161-76},
abstract = {Anopheles gambiae mosquitoes are the major vectors of human malaria parasites. However, mosquitoes are not passive hosts for parasites, actively limiting their development in vivo. Our current understanding of the mosquito antiparasitic response is mostly based on the phenotypic analysis of gene knockdowns obtained by RNA interference (RNAi), through the injection or transfection of long dsRNAs in adult mosquitoes or cultured cells, respectively. Recently, RNAi has been extended to silence specifically one allele of a given gene in a heterozygous context, thus allowing to compare the contribution of different alleles to a phenotype in the same genetic background.},
keywords = {blandin, dsRNA, M3i, RNAi},
pubstate = {published},
tppubtype = {article}
}
Anopheles gambiae mosquitoes are the major vectors of human malaria parasites. However, mosquitoes are not passive hosts for parasites, actively limiting their development in vivo. Our current understanding of the mosquito antiparasitic response is mostly based on the phenotypic analysis of gene knockdowns obtained by RNA interference (RNAi), through the injection or transfection of long dsRNAs in adult mosquitoes or cultured cells, respectively. Recently, RNAi has been extended to silence specifically one allele of a given gene in a heterozygous context, thus allowing to compare the contribution of different alleles to a phenotype in the same genetic background.
Fukuyama Hidehiro, Verdier Yann, Guan Yongsheng, Makino-Okamura Chieko, Shilova Victoria, Liu Xi, Maksoud Elie, Matsubayashi Jun, Haddad Iman, Spirohn Kerstin, Ono Kenichiro, Hetru Charles, Rossier Jean, Ideker Trey, Boutros Michael, Vinh Joëlle, Hoffmann Jules A
Landscape of protein-protein interactions in Drosophila immune deficiency signaling during bacterial challenge Article de journal
Dans: Proc. Natl. Acad. Sci. U.S.A., vol. 110, no. 26, p. 10717–10722, 2013, ISSN: 1091-6490.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Chromatin Assembly and Disassembly, Escherichia coli, functional proteomics, Genes, Genetically Modified, Histone Acetyltransferases, hoffmann, Host-Pathogen Interactions, Humans, IMD interactome, Insect, M3i, Models, Molecular, Protein Interaction Maps, Sequence Homology, Signal Transduction, small ubiquitin-like modifier
@article{fukuyama_landscape_2013,
title = {Landscape of protein-protein interactions in Drosophila immune deficiency signaling during bacterial challenge},
author = {Hidehiro Fukuyama and Yann Verdier and Yongsheng Guan and Chieko Makino-Okamura and Victoria Shilova and Xi Liu and Elie Maksoud and Jun Matsubayashi and Iman Haddad and Kerstin Spirohn and Kenichiro Ono and Charles Hetru and Jean Rossier and Trey Ideker and Michael Boutros and Joëlle Vinh and Jules A Hoffmann},
doi = {10.1073/pnas.1304380110},
issn = {1091-6490},
year = {2013},
date = {2013-06-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {110},
number = {26},
pages = {10717--10722},
abstract = {The Drosophila defense against pathogens largely relies on the activation of two signaling pathways: immune deficiency (IMD) and Toll. The IMD pathway is triggered mainly by Gram-negative bacteria, whereas the Toll pathway responds predominantly to Gram-positive bacteria and fungi. The activation of these pathways leads to the rapid induction of numerous NF-κB-induced immune response genes, including antimicrobial peptide genes. The IMD pathway shows significant similarities with the TNF receptor pathway. Recent evidence indicates that the IMD pathway is also activated in response to various noninfectious stimuli (i.e., inflammatory-like reactions). To gain a better understanding of the molecular machinery underlying the pleiotropic functions of this pathway, we first performed a comprehensive proteomics analysis to identify the proteins interacting with the 11 canonical members of the pathway initially identified by genetic studies. We identified 369 interacting proteins (corresponding to 291 genes) in heat-killed Escherichia coli-stimulated Drosophila S2 cells, 92% of which have human orthologs. A comparative analysis of gene ontology from fly or human gene annotation databases points to four significant common categories: (i) the NuA4, nucleosome acetyltransferase of H4, histone acetyltransferase complex, (ii) the switching defective/sucrose nonfermenting-type chromatin remodeling complex, (iii) transcription coactivator activity, and (iv) translation factor activity. Here we demonstrate that sumoylation of the IκB kinase homolog immune response-deficient 5 plays an important role in the induction of antimicrobial peptide genes through a highly conserved sumoylation consensus site during bacterial challenge. Taken together, the proteomics data presented here provide a unique avenue for a comparative functional analysis of proteins involved in innate immune reactions in flies and mammals.},
keywords = {Amino Acid, Animals, Chromatin Assembly and Disassembly, Escherichia coli, functional proteomics, Genes, Genetically Modified, Histone Acetyltransferases, hoffmann, Host-Pathogen Interactions, Humans, IMD interactome, Insect, M3i, Models, Molecular, Protein Interaction Maps, Sequence Homology, Signal Transduction, small ubiquitin-like modifier},
pubstate = {published},
tppubtype = {article}
}
The Drosophila defense against pathogens largely relies on the activation of two signaling pathways: immune deficiency (IMD) and Toll. The IMD pathway is triggered mainly by Gram-negative bacteria, whereas the Toll pathway responds predominantly to Gram-positive bacteria and fungi. The activation of these pathways leads to the rapid induction of numerous NF-κB-induced immune response genes, including antimicrobial peptide genes. The IMD pathway shows significant similarities with the TNF receptor pathway. Recent evidence indicates that the IMD pathway is also activated in response to various noninfectious stimuli (i.e., inflammatory-like reactions). To gain a better understanding of the molecular machinery underlying the pleiotropic functions of this pathway, we first performed a comprehensive proteomics analysis to identify the proteins interacting with the 11 canonical members of the pathway initially identified by genetic studies. We identified 369 interacting proteins (corresponding to 291 genes) in heat-killed Escherichia coli-stimulated Drosophila S2 cells, 92% of which have human orthologs. A comparative analysis of gene ontology from fly or human gene annotation databases points to four significant common categories: (i) the NuA4, nucleosome acetyltransferase of H4, histone acetyltransferase complex, (ii) the switching defective/sucrose nonfermenting-type chromatin remodeling complex, (iii) transcription coactivator activity, and (iv) translation factor activity. Here we demonstrate that sumoylation of the IκB kinase homolog immune response-deficient 5 plays an important role in the induction of antimicrobial peptide genes through a highly conserved sumoylation consensus site during bacterial challenge. Taken together, the proteomics data presented here provide a unique avenue for a comparative functional analysis of proteins involved in innate immune reactions in flies and mammals.
Kobayashi Taira, Ogawa Michinaga, Sanada Takahito, Mimuro Hitomi, Kim Minsoo, Ashida Hiroshi, Akakura Reiko, Yoshida Mitsutaka, Kawalec Magdalena, Reichhart Jean-Marc, Mizushima Tsunehiro, Sasakawa Chihiro
The Shigella OspC3 effector inhibits caspase-4, antagonizes inflammatory cell death, and promotes epithelial infection Article de journal
Dans: Cell Host Microbe, vol. 13, no. 5, p. 570–583, 2013, ISSN: 1934-6069.
Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Bacillary, Bacterial, Bacterial Proteins, Caspases, Cell Death, Cell Line, Disease Models, DNA, Dysentery, Enzyme Inhibitors, Epithelial Cells, Escherichia coli, Gene Knockout Techniques, Guinea Pigs, Host-Pathogen Interactions, Humans, Initiator, M3i, Protein Binding, Protein Interaction Mapping, reichhart, Salmonella typhimurium, Sequence Analysis, Shigella flexneri, Virulence Factors
@article{kobayashi_shigella_2013,
title = {The Shigella OspC3 effector inhibits caspase-4, antagonizes inflammatory cell death, and promotes epithelial infection},
author = {Taira Kobayashi and Michinaga Ogawa and Takahito Sanada and Hitomi Mimuro and Minsoo Kim and Hiroshi Ashida and Reiko Akakura and Mitsutaka Yoshida and Magdalena Kawalec and Jean-Marc Reichhart and Tsunehiro Mizushima and Chihiro Sasakawa},
doi = {10.1016/j.chom.2013.04.012},
issn = {1934-6069},
year = {2013},
date = {2013-05-01},
journal = {Cell Host Microbe},
volume = {13},
number = {5},
pages = {570--583},
abstract = {Caspase-mediated inflammatory cell death acts as an intrinsic defense mechanism against infection. Bacterial pathogens deploy countermeasures against inflammatory cell death, but the mechanisms by which they do this remain largely unclear. In a screen for Shigella flexneri effectors that regulate cell death during infection, we discovered that Shigella infection induced acute inflammatory, caspase-4-dependent epithelial cell death, which is counteracted by the bacterial OspC3 effector. OspC3 interacts with the caspase-4-p19 subunit and inhibits its activation by preventing caspase-4-p19 and caspase-4-p10 heterodimerization by depositing the conserved OspC3 X1-Y-X₂-D-X₃ motif at the putative catalytic pocket of caspase-4. Infection of guinea pigs with a Shigella ospC3-deficient mutant resulted in enhanced inflammatory cell death and associated symptoms, correlating with decreased bacterial burdens. Salmonella Typhimurium and enteropathogenic Escherichia coli infection also induced caspase-4-dependent epithelial death. These findings highlight the importance of caspase-4-dependent innate immune responses and demonstrate that Shigella delivers a caspase-4-specific inhibitor to delay epithelial cell death and promote infection.},
keywords = {Animal, Animals, Bacillary, Bacterial, Bacterial Proteins, Caspases, Cell Death, Cell Line, Disease Models, DNA, Dysentery, Enzyme Inhibitors, Epithelial Cells, Escherichia coli, Gene Knockout Techniques, Guinea Pigs, Host-Pathogen Interactions, Humans, Initiator, M3i, Protein Binding, Protein Interaction Mapping, reichhart, Salmonella typhimurium, Sequence Analysis, Shigella flexneri, Virulence Factors},
pubstate = {published},
tppubtype = {article}
}
Caspase-mediated inflammatory cell death acts as an intrinsic defense mechanism against infection. Bacterial pathogens deploy countermeasures against inflammatory cell death, but the mechanisms by which they do this remain largely unclear. In a screen for Shigella flexneri effectors that regulate cell death during infection, we discovered that Shigella infection induced acute inflammatory, caspase-4-dependent epithelial cell death, which is counteracted by the bacterial OspC3 effector. OspC3 interacts with the caspase-4-p19 subunit and inhibits its activation by preventing caspase-4-p19 and caspase-4-p10 heterodimerization by depositing the conserved OspC3 X1-Y-X₂-D-X₃ motif at the putative catalytic pocket of caspase-4. Infection of guinea pigs with a Shigella ospC3-deficient mutant resulted in enhanced inflammatory cell death and associated symptoms, correlating with decreased bacterial burdens. Salmonella Typhimurium and enteropathogenic Escherichia coli infection also induced caspase-4-dependent epithelial death. These findings highlight the importance of caspase-4-dependent innate immune responses and demonstrate that Shigella delivers a caspase-4-specific inhibitor to delay epithelial cell death and promote infection.
Quintin Jessica, Asmar Joelle, Matskevich Alexey A, Lafarge Marie-Céline, Ferrandon Dominique
The Drosophila Toll pathway controls but does not clear Candida glabrata infections Article de journal
Dans: J. Immunol., vol. 190, no. 6, p. 2818–2827, 2013, ISSN: 1550-6606.
Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence
@article{quintin_drosophila_2013b,
title = {The Drosophila Toll pathway controls but does not clear Candida glabrata infections},
author = {Jessica Quintin and Joelle Asmar and Alexey A Matskevich and Marie-Céline Lafarge and Dominique Ferrandon},
doi = {10.4049/jimmunol.1201861},
issn = {1550-6606},
year = {2013},
date = {2013-03-01},
journal = {J. Immunol.},
volume = {190},
number = {6},
pages = {2818--2827},
abstract = {The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host.},
keywords = {Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence},
pubstate = {published},
tppubtype = {article}
}
The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host.
Bonnay François, Cohen-Berros Eva, Hoffmann Martine, Kim Sabrina Y, Boulianne Gabrielle L, Hoffmann Jules A, Matt Nicolas, Reichhart Jean-Marc
Big bang gene modulates gut immune tolerance in Drosophila Article de journal
Dans: Proc. Natl. Acad. Sci. U.S.A., vol. 110, no. 8, p. 2957–2962, 2013, ISSN: 1091-6490.
Résumé | Liens | BibTeX | Étiquettes: Animals, hoffmann, Immune Tolerance, Longevity, M3i, matt, Membrane Proteins, reichhart
@article{bonnay_big_2013,
title = {Big bang gene modulates gut immune tolerance in Drosophila},
author = {François Bonnay and Eva Cohen-Berros and Martine Hoffmann and Sabrina Y Kim and Gabrielle L Boulianne and Jules A Hoffmann and Nicolas Matt and Jean-Marc Reichhart},
doi = {10.1073/pnas.1221910110},
issn = {1091-6490},
year = {2013},
date = {2013-02-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {110},
number = {8},
pages = {2957--2962},
abstract = {Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases.},
keywords = {Animals, hoffmann, Immune Tolerance, Longevity, M3i, matt, Membrane Proteins, reichhart},
pubstate = {published},
tppubtype = {article}
}
Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases.
Ferrandon Dominique
The complementary facets of epithelial host defenses in the genetic model organism Drosophila melanogaster: from resistance to resilience Article de journal
Dans: Curr. Opin. Immunol., vol. 25, no. 1, p. 59–70, 2013, ISSN: 1879-0372.
Résumé | Liens | BibTeX | Étiquettes: Adult Stem Cells, aging, Animal, Animals, Cell Proliferation, Disease Models, Enterocytes, ferrandon, Humans, Immunity, Intestinal Mucosa, M3i, Metagenome, Stem Cell Niche, Wound Healing
@article{ferrandon_complementary_2013b,
title = {The complementary facets of epithelial host defenses in the genetic model organism Drosophila melanogaster: from resistance to resilience},
author = {Dominique Ferrandon},
doi = {10.1016/j.coi.2012.11.008},
issn = {1879-0372},
year = {2013},
date = {2013-02-01},
journal = {Curr. Opin. Immunol.},
volume = {25},
number = {1},
pages = {59--70},
abstract = {Significant advances have been made in our understanding of the host defense against microbial infections taking place at frontier epithelia of Drosophila flies. Immune deficiency (IMD), the major NF-κB immune response pathway induced in these epithelia, displays remarkable adaptations in its activation and regulation in the respiratory and digestive tract. The host defense against ingested pathogens is not limited to resistance, that is, the immune response. It also involves resilience, the capacity of the host to endure and repair damages inflicted by pathogens or the host's own immune response. For instance, enterocytes damaged by pathogens, the microbiota of aging flies, or host-derived reactive oxygen species (ROS), are replaced under the control of multiple pathways by the compensatory proliferation of intestinal stem cells (ISCs).},
keywords = {Adult Stem Cells, aging, Animal, Animals, Cell Proliferation, Disease Models, Enterocytes, ferrandon, Humans, Immunity, Intestinal Mucosa, M3i, Metagenome, Stem Cell Niche, Wound Healing},
pubstate = {published},
tppubtype = {article}
}
Significant advances have been made in our understanding of the host defense against microbial infections taking place at frontier epithelia of Drosophila flies. Immune deficiency (IMD), the major NF-κB immune response pathway induced in these epithelia, displays remarkable adaptations in its activation and regulation in the respiratory and digestive tract. The host defense against ingested pathogens is not limited to resistance, that is, the immune response. It also involves resilience, the capacity of the host to endure and repair damages inflicted by pathogens or the host's own immune response. For instance, enterocytes damaged by pathogens, the microbiota of aging flies, or host-derived reactive oxygen species (ROS), are replaced under the control of multiple pathways by the compensatory proliferation of intestinal stem cells (ISCs).
Baron Olga Lucia, van West Pieter, Industri Benoit, Ponchet Michel, Dubreuil Géraldine, Gourbal Benjamin, Reichhart Jean-Marc, Coustau Christine
Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections Article de journal
Dans: PLoS Pathog., vol. 9, no. 12, p. e1003792, 2013, ISSN: 1553-7374.
Résumé | Liens | BibTeX | Étiquettes: Acute-Phase Proteins, Animals, Antimicrobial Cationic Peptides, Biomphalaria, Blood Proteins, Carrier Proteins, Cell Membrane, Cell Membrane Permeability, Cloning, Escherichia coli, Female, Immunity, infection, M3i, Maternally-Acquired, Membrane Glycoproteins, Microbial Sensitivity Tests, Molecular, Oomycetes, Recombinant Proteins, reichhart, Zygote
@article{baron_parental_2013,
title = {Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections},
author = {Olga Lucia Baron and Pieter van West and Benoit Industri and Michel Ponchet and Géraldine Dubreuil and Benjamin Gourbal and Jean-Marc Reichhart and Christine Coustau},
doi = {10.1371/journal.ppat.1003792},
issn = {1553-7374},
year = {2013},
date = {2013-01-01},
journal = {PLoS Pathog.},
volume = {9},
number = {12},
pages = {e1003792},
abstract = {Vertebrate females transfer antibodies via the placenta, colostrum and milk or via the egg yolk to protect their immunologically immature offspring against pathogens. This evolutionarily important transfer of immunity is poorly documented in invertebrates and basic questions remain regarding the nature and extent of parental protection of offspring. In this study, we show that a lipopolysaccharide binding protein/bactericidal permeability increasing protein family member from the invertebrate Biomphalaria glabrata (BgLBP/BPI1) is massively loaded into the eggs of this freshwater snail. Native and recombinant proteins displayed conserved LPS-binding, antibacterial and membrane permeabilizing activities. A broad screening of various pathogens revealed a previously unknown biocidal activity of the protein against pathogenic water molds (oomycetes), which is conserved in human BPI. RNAi-dependent silencing of LBP/BPI in the parent snails resulted in a significant reduction of reproductive success and extensive death of eggs through oomycete infections. This work provides the first functional evidence that a LBP/BPI is involved in the parental immune protection of invertebrate offspring and reveals a novel and conserved biocidal activity for LBP/BPI family members.},
keywords = {Acute-Phase Proteins, Animals, Antimicrobial Cationic Peptides, Biomphalaria, Blood Proteins, Carrier Proteins, Cell Membrane, Cell Membrane Permeability, Cloning, Escherichia coli, Female, Immunity, infection, M3i, Maternally-Acquired, Membrane Glycoproteins, Microbial Sensitivity Tests, Molecular, Oomycetes, Recombinant Proteins, reichhart, Zygote},
pubstate = {published},
tppubtype = {article}
}
Vertebrate females transfer antibodies via the placenta, colostrum and milk or via the egg yolk to protect their immunologically immature offspring against pathogens. This evolutionarily important transfer of immunity is poorly documented in invertebrates and basic questions remain regarding the nature and extent of parental protection of offspring. In this study, we show that a lipopolysaccharide binding protein/bactericidal permeability increasing protein family member from the invertebrate Biomphalaria glabrata (BgLBP/BPI1) is massively loaded into the eggs of this freshwater snail. Native and recombinant proteins displayed conserved LPS-binding, antibacterial and membrane permeabilizing activities. A broad screening of various pathogens revealed a previously unknown biocidal activity of the protein against pathogenic water molds (oomycetes), which is conserved in human BPI. RNAi-dependent silencing of LBP/BPI in the parent snails resulted in a significant reduction of reproductive success and extensive death of eggs through oomycete infections. This work provides the first functional evidence that a LBP/BPI is involved in the parental immune protection of invertebrate offspring and reveals a novel and conserved biocidal activity for LBP/BPI family members.
Ayyaz Arshad, Giammarinaro Philippe, Liégeois Samuel, Lestradet Matthieu, Ferrandon Dominique
Dans: Immunobiology, vol. 218, no. 4, p. 635–644, 2013, ISSN: 1878-3279.
Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animal, Animals, Antigens, Differentiation, Disease Models, ferrandon, Immunity, Immunologic, Innate, Intestinal Diseases, M3i, Mucosal, Mutation, Receptors, Signal Transducing, Staphylococcal Infections, Staphylococcus, Starvation, Toll-Like Receptors
@article{ayyaz_negative_2013b,
title = {A negative role for MyD88 in the resistance to starvation as revealed in an intestinal infection of Drosophila melanogaster with the Gram-positive bacterium Staphylococcus xylosus},
author = {Arshad Ayyaz and Philippe Giammarinaro and Samuel Liégeois and Matthieu Lestradet and Dominique Ferrandon},
doi = {10.1016/j.imbio.2012.07.027},
issn = {1878-3279},
year = {2013},
date = {2013-01-01},
journal = {Immunobiology},
volume = {218},
number = {4},
pages = {635--644},
abstract = {Drosophila melanogaster is a useful model to investigate mucosal immunity. The immune response to intestinal infections is mediated partly by the Immune deficiency (IMD) pathway, which only gets activated by a type of peptidoglycan lacking in several medically important Gram-positive bacterial species such as Staphylococcus. Thus, the intestinal host defense against such bacterial strains remains poorly known. Here, we have used Staphylococcus xylosus to develop a model of intestinal infections by Gram-positive bacteria. S. xylosus behaves as an opportunistic pathogen in a septic injury model, being able to kill only flies immunodeficient either for the Toll pathway or the cellular response. When ingested, it is controlled by IMD-independent host intestinal defenses, yet flies eventually die. Having excluded an overreaction of the immune response and the action of toxins, we find that flies actually succumb to starvation, likely as a result of a competition for sucrose between the bacteria and the flies. Fat stores of wild-type flies are severely reduced within a day, a period when sucrose is not yet exhausted in the feeding solution. Interestingly, the Toll pathway mutant MyD88 is more resistant to the ingestion of S. xylosus and to starvation than wild-type flies. MyD88 flies do not rapidly deplete their fat stores when starved, in contrast to wild-type flies. Thus, we have uncovered a novel function of MyD88 in the regulation of metabolism that appears to be independent of its known roles in immunity and development.},
keywords = {Adaptor Proteins, Animal, Animals, Antigens, Differentiation, Disease Models, ferrandon, Immunity, Immunologic, Innate, Intestinal Diseases, M3i, Mucosal, Mutation, Receptors, Signal Transducing, Staphylococcal Infections, Staphylococcus, Starvation, Toll-Like Receptors},
pubstate = {published},
tppubtype = {article}
}
Drosophila melanogaster is a useful model to investigate mucosal immunity. The immune response to intestinal infections is mediated partly by the Immune deficiency (IMD) pathway, which only gets activated by a type of peptidoglycan lacking in several medically important Gram-positive bacterial species such as Staphylococcus. Thus, the intestinal host defense against such bacterial strains remains poorly known. Here, we have used Staphylococcus xylosus to develop a model of intestinal infections by Gram-positive bacteria. S. xylosus behaves as an opportunistic pathogen in a septic injury model, being able to kill only flies immunodeficient either for the Toll pathway or the cellular response. When ingested, it is controlled by IMD-independent host intestinal defenses, yet flies eventually die. Having excluded an overreaction of the immune response and the action of toxins, we find that flies actually succumb to starvation, likely as a result of a competition for sucrose between the bacteria and the flies. Fat stores of wild-type flies are severely reduced within a day, a period when sucrose is not yet exhausted in the feeding solution. Interestingly, the Toll pathway mutant MyD88 is more resistant to the ingestion of S. xylosus and to starvation than wild-type flies. MyD88 flies do not rapidly deplete their fat stores when starved, in contrast to wild-type flies. Thus, we have uncovered a novel function of MyD88 in the regulation of metabolism that appears to be independent of its known roles in immunity and development.
2012
Marois Eric, Scali C, Soichot Julien, Kappler Christine, Levashina Elena A, Catteruccia Flaminia
High-throughput sorting of mosquito larvae for laboratory studies and for future vector control interventions Article de journal
Dans: Malaria J., vol. 11, p. 302, 2012.
Résumé | Liens | BibTeX | Étiquettes: COPAS, M3i, marois, Sorting, transgenesis
@article{E2012,
title = {High-throughput sorting of mosquito larvae for laboratory studies and for future vector control interventions},
author = {Eric Marois and C Scali and Julien Soichot and Christine Kappler and Elena A Levashina and Flaminia Catteruccia},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22929810},
year = {2012},
date = {2012-08-28},
journal = {Malaria J.},
volume = {11},
pages = {302},
abstract = {BACKGROUND: Mosquito transgenesis offers new promises for the genetic control of vector-borne infectious diseases such as malaria and dengue fever. Genetic control strategies require the release of large number of male mosquitoes into field populations, whether they are based on the use of sterile males (sterile insect technique, SIT) or on introducing genetic traits conferring refractoriness to disease transmission (population replacement). However, the current absence of high-throughput techniques for sorting different mosquito populations impairs the application of these control measures. METHODS: A method was developed to generate large mosquito populations of the desired sex and genotype. This method combines flow cytometry and the use of Anopheles gambiae transgenic lines that differentially express fluorescent markers in males and females. RESULTS: Fluorescence-assisted sorting allowed single-step isolation of homozygous transgenic mosquitoes from a mixed population. This method was also used to select wild-type males only with high efficiency and accuracy, a highly desirable tool for genetic control strategies where the release of transgenic individuals may be problematic. Importantly, sorted males showed normal mating ability compared to their unsorted brothers. CONCLUSIONS: The developed method will greatly facilitate both laboratory studies of mosquito vectorial capacity requiring high-throughput approaches and future field interventions in the fight against infectious disease vectors.},
keywords = {COPAS, M3i, marois, Sorting, transgenesis},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Mosquito transgenesis offers new promises for the genetic control of vector-borne infectious diseases such as malaria and dengue fever. Genetic control strategies require the release of large number of male mosquitoes into field populations, whether they are based on the use of sterile males (sterile insect technique, SIT) or on introducing genetic traits conferring refractoriness to disease transmission (population replacement). However, the current absence of high-throughput techniques for sorting different mosquito populations impairs the application of these control measures. METHODS: A method was developed to generate large mosquito populations of the desired sex and genotype. This method combines flow cytometry and the use of Anopheles gambiae transgenic lines that differentially express fluorescent markers in males and females. RESULTS: Fluorescence-assisted sorting allowed single-step isolation of homozygous transgenic mosquitoes from a mixed population. This method was also used to select wild-type males only with high efficiency and accuracy, a highly desirable tool for genetic control strategies where the release of transgenic individuals may be problematic. Importantly, sorted males showed normal mating ability compared to their unsorted brothers. CONCLUSIONS: The developed method will greatly facilitate both laboratory studies of mosquito vectorial capacity requiring high-throughput approaches and future field interventions in the fight against infectious disease vectors.
Ezekowitz Alan R B, Dimarcq Jean-Luc, Kafatos Fotis, Levashina Elena A, Ferrandon Dominique, Hetru Charles, Imler Jean-Luc, Reichhart Jean-Marc
Lawrence's book review unfair to Hoffmann Article de journal
Dans: Curr. Biol., vol. 22, no. 12, p. R482, 2012, ISSN: 1879-0445.
Liens | BibTeX | Étiquettes: Book Reviews as Topic, Ethics, ferrandon, imler, M3i, Professional, reichhart
@article{ezekowitz_lawrences_2012,
title = {Lawrence's book review unfair to Hoffmann},
author = {Alan R B Ezekowitz and Jean-Luc Dimarcq and Fotis Kafatos and Elena A Levashina and Dominique Ferrandon and Charles Hetru and Jean-Luc Imler and Jean-Marc Reichhart},
doi = {10.1016/j.cub.2012.05.015},
issn = {1879-0445},
year = {2012},
date = {2012-06-01},
journal = {Curr. Biol.},
volume = {22},
number = {12},
pages = {R482},
keywords = {Book Reviews as Topic, Ethics, ferrandon, imler, M3i, Professional, reichhart},
pubstate = {published},
tppubtype = {article}
}
Imler Jean-Luc, Hoffmann Jules A
Nucleic Acid Sensors and Antiviral Immunity Chapitre d'ouvrage
Dans: eds T. Fujita & P. Sambhara, (Ed.): Chapitre 1 : Antiviral responses in invertebrates, p. 1-18, Landes Bioscience, 2012.
BibTeX | Étiquettes: antiviral immunity, hoffmann, imler, Invertebrate, M3i
@inbook{Imler2012,
title = {Nucleic Acid Sensors and Antiviral Immunity},
author = {Jean-Luc Imler and Jules A Hoffmann},
editor = {eds T. Fujita & P. Sambhara},
year = {2012},
date = {2012-06-01},
pages = {1-18},
publisher = {Landes Bioscience},
chapter = {1 : Antiviral responses in invertebrates},
keywords = {antiviral immunity, hoffmann, imler, Invertebrate, M3i},
pubstate = {published},
tppubtype = {inbook}
}
Lemaitre Bruno, Nicolas Emmanuelle, Michaut Lydia, Reichhart Jean-Marc, Hoffmann Jules A
Pillars article: the dorsoventral regulatory gene cassette spätzle/Toll/cactus controls the potent antifungal response in Drosophila adults. Cell. 1996. 86: 973-983 Article de journal
Dans: J. Immunol., vol. 188, no. 11, p. 5210–5220, 2012, ISSN: 1550-6606.
Résumé | BibTeX | Étiquettes: Animals, Antifungal Agents, Developmental, DNA-Binding Proteins, Gene Expression Regulation, history, hoffmann, M3i, Multigene Family, Mycoses, Phosphoproteins, reichhart, Toll-Like Receptors
@article{lemaitre_pillars_2012,
title = {Pillars article: the dorsoventral regulatory gene cassette spätzle/Toll/cactus controls the potent antifungal response in Drosophila adults. Cell. 1996. 86: 973-983},
author = {Bruno Lemaitre and Emmanuelle Nicolas and Lydia Michaut and Jean-Marc Reichhart and Jules A Hoffmann},
issn = {1550-6606},
year = {2012},
date = {2012-06-01},
journal = {J. Immunol.},
volume = {188},
number = {11},
pages = {5210--5220},
abstract = {The cytokine-induced activation cascade of NF-kappaB in mammals and the activation of the morphogen dorsal in Drosophila embryos show striking structural and functional similarities (Toll/IL-1, Cactus/I-kappaB, and dorsal/NF-kappaB). Here we demonstrate that these parallels extend to the immune response of Drosophila. In particular, the intracellular components of the dorsoventral signaling pathway (except for dorsal) and the extracellular Toll ligand, spätzle regulatory gene cassette, control expression of the antifungal peptide gene drosomycin in adults. We also show that mutations in the Toll signaling pathway dramatically reduce survival after fungal infection. Antibacterial genes are induced either by a distinct pathway involving the immune deficiency gene (imd) or by combined activation of both imd and dorsoventral pathways.},
keywords = {Animals, Antifungal Agents, Developmental, DNA-Binding Proteins, Gene Expression Regulation, history, hoffmann, M3i, Multigene Family, Mycoses, Phosphoproteins, reichhart, Toll-Like Receptors},
pubstate = {published},
tppubtype = {article}
}
The cytokine-induced activation cascade of NF-kappaB in mammals and the activation of the morphogen dorsal in Drosophila embryos show striking structural and functional similarities (Toll/IL-1, Cactus/I-kappaB, and dorsal/NF-kappaB). Here we demonstrate that these parallels extend to the immune response of Drosophila. In particular, the intracellular components of the dorsoventral signaling pathway (except for dorsal) and the extracellular Toll ligand, spätzle regulatory gene cassette, control expression of the antifungal peptide gene drosomycin in adults. We also show that mutations in the Toll signaling pathway dramatically reduce survival after fungal infection. Antibacterial genes are induced either by a distinct pathway involving the immune deficiency gene (imd) or by combined activation of both imd and dorsoventral pathways.
Ramakrishnan Chandra, Rademacher Annika, Soichot Julien, Costa Giulia, Waters Andy P, Janse Chris J, Ramesar J, Franke-Fayard Blandine M, Levashina Elena A
Salivary gland-specific P. berghei reporter lines enable rapid evaluation of tissue-specific sporozoite loads in mosquitoes Article de journal
Dans: PLoS One, vol. 7, no. 5, p. e36376, 2012.
Résumé | Liens | BibTeX | Étiquettes: luciferase, M3i, Plasmodium berghei, salivary gland
@article{C2012,
title = {Salivary gland-specific P. berghei reporter lines enable rapid evaluation of tissue-specific sporozoite loads in mosquitoes},
author = {Chandra Ramakrishnan and Annika Rademacher and Julien Soichot and Giulia Costa and Andy P Waters and Chris J Janse and J Ramesar and Blandine M Franke-Fayard and Elena A Levashina},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22574152},
year = {2012},
date = {2012-05-04},
journal = {PLoS One},
volume = {7},
number = {5},
pages = {e36376},
abstract = {Malaria is a life-threatening human infectious disease transmitted by mosquitoes. Levels of the salivary gland sporozoites (sgs), the only mosquito stage infectious to a mammalian host, represent an important cumulative index of Plasmodium development within a mosquito. However, current techniques of sgs quantification are laborious and imprecise. Here, transgenic P. berghei reporter lines that produce the green fluorescent protein fused to luciferase (GFP-LUC) specifically in sgs were generated, verified and characterised. Fluorescence microscopy confirmed the sgs stage specificity of expression of the reporter gene. The luciferase activity of the reporter lines was then exploited to establish a simple and fast biochemical assay to evaluate sgs loads in whole mosquitoes. Using this assay we successfully identified differences in sgs loads in mosquitoes silenced for genes that display opposing effects on P. berghei ookinete/oocyst development. It offers a new powerful tool to study infectivity of P. berghei to the mosquito, including analysis of vector-parasite interactions and evaluation of transmission-blocking vaccines.},
keywords = {luciferase, M3i, Plasmodium berghei, salivary gland},
pubstate = {published},
tppubtype = {article}
}
Malaria is a life-threatening human infectious disease transmitted by mosquitoes. Levels of the salivary gland sporozoites (sgs), the only mosquito stage infectious to a mammalian host, represent an important cumulative index of Plasmodium development within a mosquito. However, current techniques of sgs quantification are laborious and imprecise. Here, transgenic P. berghei reporter lines that produce the green fluorescent protein fused to luciferase (GFP-LUC) specifically in sgs were generated, verified and characterised. Fluorescence microscopy confirmed the sgs stage specificity of expression of the reporter gene. The luciferase activity of the reporter lines was then exploited to establish a simple and fast biochemical assay to evaluate sgs loads in whole mosquitoes. Using this assay we successfully identified differences in sgs loads in mosquitoes silenced for genes that display opposing effects on P. berghei ookinete/oocyst development. It offers a new powerful tool to study infectivity of P. berghei to the mosquito, including analysis of vector-parasite interactions and evaluation of transmission-blocking vaccines.
Goto Akira, Imler Jean-Luc
Toll signaling in flies and mammals: two sorts of MyD88 Article de journal
Dans: Immunity, vol. 36, no. 4, p. 555–557, 2012, ISSN: 1097-4180.
Résumé | Liens | BibTeX | Étiquettes: imler, M3i
@article{goto_toll_2012,
title = {Toll signaling in flies and mammals: two sorts of MyD88},
author = {Akira Goto and Jean-Luc Imler},
doi = {10.1016/j.immuni.2012.04.001},
issn = {1097-4180},
year = {2012},
date = {2012-04-01},
journal = {Immunity},
volume = {36},
number = {4},
pages = {555--557},
abstract = {The mammalian MyD88 signaling molecule participates in Toll receptor signaling within the cytoplasm. In this issue of Immunity, Marek and Kagan (2012) report that Drosophila (d)MyD88 acts instead at the plasma membrane to sort the signaling adaptor Tube.},
keywords = {imler, M3i},
pubstate = {published},
tppubtype = {article}
}
The mammalian MyD88 signaling molecule participates in Toll receptor signaling within the cytoplasm. In this issue of Immunity, Marek and Kagan (2012) report that Drosophila (d)MyD88 acts instead at the plasma membrane to sort the signaling adaptor Tube.
Coste Franck, Kemp Cordula, Bobezeau Vanessa, Hetru Charles, Kellenberger Christine, Imler Jean-Luc, Roussel Alain
Crystal structure of Diedel, a marker of the immune response of Drosophila melanogaster Article de journal
Dans: PloS One, vol. 7, no. 3, p. e33416, 2012, ISSN: 1932-6203.
Résumé | Liens | BibTeX | Étiquettes: Animals, Aphids, Crystallography, imler, Janus Kinases, M3i, Protein Folding, Protein Structure, Signal Transduction, STAT Transcription Factors, Tertiary, Transcription Factors, X-Ray
@article{coste_crystal_2012,
title = {Crystal structure of Diedel, a marker of the immune response of Drosophila melanogaster},
author = {Franck Coste and Cordula Kemp and Vanessa Bobezeau and Charles Hetru and Christine Kellenberger and Jean-Luc Imler and Alain Roussel},
doi = {10.1371/journal.pone.0033416},
issn = {1932-6203},
year = {2012},
date = {2012-01-01},
journal = {PloS One},
volume = {7},
number = {3},
pages = {e33416},
abstract = {BACKGROUND: The Drosophila melanogaster gene CG11501 is up regulated after a septic injury and was proposed to act as a negative regulator of the JAK/STAT signaling pathway. Diedel, the CG11501 gene product, is a small protein of 115 residues with 10 cysteines. METHODOLOGY/PRINCIPAL FINDINGS: We have produced Diedel in Drosophila S2 cells as an extra cellular protein thanks to its own signal peptide and solved its crystal structure at 1.15 Å resolution by SIRAS using an iodo derivative. Diedel is composed of two sub domains SD1 and SD2. SD1 is made of an antiparallel β-sheet covered by an α-helix and displays a ferredoxin-like fold. SD2 reveals a new protein fold made of loops connected by four disulfide bridges. Further structural analysis identified conserved hydrophobic residues on the surface of Diedel that may constitute a potential binding site. The existence of two conformations, cis and trans, for the proline 52 may be of interest as prolyl peptidyl isomerisation has been shown to play a role in several physiological mechanisms. The genome of D. melanogaster contains two other genes coding for proteins homologous to Diedel, namely CG43228 and CG34329. Strikingly, apart from Drosophila and the pea aphid Acyrthosiphon pisum, Diedel-related sequences were exclusively identified in a few insect DNA viruses of the Baculoviridae and Ascoviridae families. CONCLUSION/SIGNIFICANCE: Diedel, a marker of the Drosophila antimicrobial/antiviral response, is a member of a small family of proteins present in drosophilids, aphids and DNA viruses infecting lepidopterans. Diedel is an extracellular protein composed of two sub-domains. Two special structural features (hydrophobic surface patch and cis/trans conformation for proline 52) may indicate a putative interaction site, and support an extra cellular signaling function for Diedel, which is in accordance with its proposed role as negative regulator of the JAK/STAT signaling pathway.},
keywords = {Animals, Aphids, Crystallography, imler, Janus Kinases, M3i, Protein Folding, Protein Structure, Signal Transduction, STAT Transcription Factors, Tertiary, Transcription Factors, X-Ray},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: The Drosophila melanogaster gene CG11501 is up regulated after a septic injury and was proposed to act as a negative regulator of the JAK/STAT signaling pathway. Diedel, the CG11501 gene product, is a small protein of 115 residues with 10 cysteines. METHODOLOGY/PRINCIPAL FINDINGS: We have produced Diedel in Drosophila S2 cells as an extra cellular protein thanks to its own signal peptide and solved its crystal structure at 1.15 Å resolution by SIRAS using an iodo derivative. Diedel is composed of two sub domains SD1 and SD2. SD1 is made of an antiparallel β-sheet covered by an α-helix and displays a ferredoxin-like fold. SD2 reveals a new protein fold made of loops connected by four disulfide bridges. Further structural analysis identified conserved hydrophobic residues on the surface of Diedel that may constitute a potential binding site. The existence of two conformations, cis and trans, for the proline 52 may be of interest as prolyl peptidyl isomerisation has been shown to play a role in several physiological mechanisms. The genome of D. melanogaster contains two other genes coding for proteins homologous to Diedel, namely CG43228 and CG34329. Strikingly, apart from Drosophila and the pea aphid Acyrthosiphon pisum, Diedel-related sequences were exclusively identified in a few insect DNA viruses of the Baculoviridae and Ascoviridae families. CONCLUSION/SIGNIFICANCE: Diedel, a marker of the Drosophila antimicrobial/antiviral response, is a member of a small family of proteins present in drosophilids, aphids and DNA viruses infecting lepidopterans. Diedel is an extracellular protein composed of two sub-domains. Two special structural features (hydrophobic surface patch and cis/trans conformation for proline 52) may indicate a putative interaction site, and support an extra cellular signaling function for Diedel, which is in accordance with its proposed role as negative regulator of the JAK/STAT signaling pathway.
Deleury Emeline, Dubreuil Géraldine, Elangovan Namasivayam, Wajnberg Eric, Reichhart Jean-Marc, Gourbal Benjamin, Duval David, Baron Olga Lucia, Gouzy Jérôme, Coustau Christine
Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study Article de journal
Dans: PLoS ONE, vol. 7, no. 3, p. e32512, 2012, ISSN: 1932-6203.
Résumé | Liens | BibTeX | Étiquettes: Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers
@article{deleury_specific_2012,
title = {Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study},
author = {Emeline Deleury and Géraldine Dubreuil and Namasivayam Elangovan and Eric Wajnberg and Jean-Marc Reichhart and Benjamin Gourbal and David Duval and Olga Lucia Baron and Jérôme Gouzy and Christine Coustau},
doi = {10.1371/journal.pone.0032512},
issn = {1932-6203},
year = {2012},
date = {2012-01-01},
journal = {PLoS ONE},
volume = {7},
number = {3},
pages = {e32512},
abstract = {Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.},
keywords = {Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers},
pubstate = {published},
tppubtype = {article}
}
Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.
Niehus Sebastian, Giammarinaro Philippe, Liégeois Samuel, Quintin Jessica, Ferrandon Dominique
Fly culture collapse disorder: detection, prophylaxis and eradication of the microsporidian parasite Tubulinosema ratisbonensis infecting Drosophila melanogaster Article de journal
Dans: Fly (Austin), vol. 6, no. 3, p. 193–204, 2012, ISSN: 1933-6942.
Résumé | Liens | BibTeX | Étiquettes: Animals, Apansporoblastina, Apansporoblastina/*genetics/physiology, Base Sequence, cure, Disinfection, Disinfection/methods, DNA, DNA Primers, Drosophila melanogaster/*microbiology, ferrandon, fumagillin, Fungal, Fungal/chemistry, M3i, microsporidia, obligate intracellular parasitism, PCR detection, Phylogeny, Polymerase Chain Reaction, Polymerase Chain Reaction/methods, prophylaxis, Ribosomal, Ribosomal/chemistry, Sequence Alignment, Tubulinosema ratisbonensis
@article{niehus_fly_2012b,
title = {Fly culture collapse disorder: detection, prophylaxis and eradication of the microsporidian parasite Tubulinosema ratisbonensis infecting Drosophila melanogaster},
author = {Sebastian Niehus and Philippe Giammarinaro and Samuel Liégeois and Jessica Quintin and Dominique Ferrandon},
doi = {10.4161/fly.20896},
issn = {1933-6942},
year = {2012},
date = {2012-01-01},
journal = {Fly (Austin)},
volume = {6},
number = {3},
pages = {193--204},
abstract = {Drosophila melanogaster is a robust model to investigate many biological problems. It is however prone to some infections, which may endanger fly stocks if left unchecked for. One such infection is caused by an obligate fungal intracellular parasite, Tubulinosema ratisbonensis, which can be found in laboratory stocks. Here, we identify and briefly characterize a T. ratisbonensis strain that was infesting our Drosophila cultures and that required intensive measures to contain and eradicate the infection. We describe the phenotypes of infested stocks. We also report PCR-based techniques that allow the detection of infested stocks with a high sensitivity. We have developed a high-throughput qPCR assay that allows the efficient parallel screening of a large number of potentially-infested stocks. We also have investigated several prophylactic measures to prevent the further contamination of stocks, namely UV-exposure, ethanol treatment, bleaching, and desiccation. Bleaching was found to kill all spores. Other treatments were less effective but were found to be sufficient to prevent further contamination of noninfested stocks. Two treatments were efficacious in curing infested stocks (1) bleaching of eggs and subsequent raising of the larvae in clean vials; (2) fumagillin treatment. These cures only work on stocks that have not become too weak to withstand the procedures.},
keywords = {Animals, Apansporoblastina, Apansporoblastina/*genetics/physiology, Base Sequence, cure, Disinfection, Disinfection/methods, DNA, DNA Primers, Drosophila melanogaster/*microbiology, ferrandon, fumagillin, Fungal, Fungal/chemistry, M3i, microsporidia, obligate intracellular parasitism, PCR detection, Phylogeny, Polymerase Chain Reaction, Polymerase Chain Reaction/methods, prophylaxis, Ribosomal, Ribosomal/chemistry, Sequence Alignment, Tubulinosema ratisbonensis},
pubstate = {published},
tppubtype = {article}
}
Drosophila melanogaster is a robust model to investigate many biological problems. It is however prone to some infections, which may endanger fly stocks if left unchecked for. One such infection is caused by an obligate fungal intracellular parasite, Tubulinosema ratisbonensis, which can be found in laboratory stocks. Here, we identify and briefly characterize a T. ratisbonensis strain that was infesting our Drosophila cultures and that required intensive measures to contain and eradicate the infection. We describe the phenotypes of infested stocks. We also report PCR-based techniques that allow the detection of infested stocks with a high sensitivity. We have developed a high-throughput qPCR assay that allows the efficient parallel screening of a large number of potentially-infested stocks. We also have investigated several prophylactic measures to prevent the further contamination of stocks, namely UV-exposure, ethanol treatment, bleaching, and desiccation. Bleaching was found to kill all spores. Other treatments were less effective but were found to be sufficient to prevent further contamination of noninfested stocks. Two treatments were efficacious in curing infested stocks (1) bleaching of eggs and subsequent raising of the larvae in clean vials; (2) fumagillin treatment. These cures only work on stocks that have not become too weak to withstand the procedures.
Meister Marie, Ferrandon Dominique
Immune cell transdifferentiation: a complex crosstalk between circulating immune cells and the haematopoietic niche Article de journal
Dans: EMBO Rep., vol. 13, no. 1, p. 3–4, 2012, ISSN: 1469-3178.
Liens | BibTeX | Étiquettes: Animals, Cell Communication, Cell Transdifferentiation, ferrandon, Hematopoietic Stem Cells, Humans, Immune System, M3i, Signal Transduction, Stem Cell Niche
@article{meister_immune_2012,
title = {Immune cell transdifferentiation: a complex crosstalk between circulating immune cells and the haematopoietic niche},
author = {Marie Meister and Dominique Ferrandon},
doi = {10.1038/embor.2011.238},
issn = {1469-3178},
year = {2012},
date = {2012-01-01},
journal = {EMBO Rep.},
volume = {13},
number = {1},
pages = {3--4},
keywords = {Animals, Cell Communication, Cell Transdifferentiation, ferrandon, Hematopoietic Stem Cells, Humans, Immune System, M3i, Signal Transduction, Stem Cell Niche},
pubstate = {published},
tppubtype = {article}
}
Liu Xi, Sano Teruyuki, Guan Yongsheng, Nagata Shigekazu, Hoffmann Jules A, Fukuyama Hidehiro
Drosophila EYA regulates the immune response against DNA through an evolutionarily conserved threonine phosphatase motif Article de journal
Dans: PLoS ONE, vol. 7, no. 8, p. e42725, 2012, ISSN: 1932-6203.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Blotting, Conserved Sequence, Endodeoxyribonucleases, Eye Proteins, hoffmann, Immunoprecipitation, M3i, Phosphoprotein Phosphatases, Sequence Homology, Transcription Factors, Western
@article{liu_drosophila_2012,
title = {Drosophila EYA regulates the immune response against DNA through an evolutionarily conserved threonine phosphatase motif},
author = {Xi Liu and Teruyuki Sano and Yongsheng Guan and Shigekazu Nagata and Jules A Hoffmann and Hidehiro Fukuyama},
doi = {10.1371/journal.pone.0042725},
issn = {1932-6203},
year = {2012},
date = {2012-01-01},
journal = {PLoS ONE},
volume = {7},
number = {8},
pages = {e42725},
abstract = {Innate immune responses against DNA are essential to counter both pathogen infections and tissue damages. Mammalian EYAs were recently shown to play a role in regulating the innate immune responses against DNA. Here, we demonstrate that the unique Drosophila eya gene is also involved in the response specific to DNA. Haploinsufficiency of eya in mutants deficient for lysosomal DNase activity (DNaseII) reduces antimicrobial peptide gene expression, a hallmark for immune responses in flies. Like the mammalian orthologues, Drosophila EYA features a N-terminal threonine and C-terminal tyrosine phosphatase domain. Through the generation of a series of mutant EYA fly strains, we show that the threonine phosphatase domain, but not the tyrosine phosphatase domain, is responsible for the innate immune response against DNA. A similar role for the threonine phosphatase domain in mammalian EYA4 had been surmised on the basis of in vitro studies. Furthermore EYA associates with IKKβ and full-length RELISH, and the induction of the IMD pathway-dependent antimicrobial peptide gene is independent of SO. Our data provide the first in vivo demonstration for the immune function of EYA and point to their conserved immune function in response to endogenous DNA, throughout evolution.},
keywords = {Amino Acid, Animals, Blotting, Conserved Sequence, Endodeoxyribonucleases, Eye Proteins, hoffmann, Immunoprecipitation, M3i, Phosphoprotein Phosphatases, Sequence Homology, Transcription Factors, Western},
pubstate = {published},
tppubtype = {article}
}
Innate immune responses against DNA are essential to counter both pathogen infections and tissue damages. Mammalian EYAs were recently shown to play a role in regulating the innate immune responses against DNA. Here, we demonstrate that the unique Drosophila eya gene is also involved in the response specific to DNA. Haploinsufficiency of eya in mutants deficient for lysosomal DNase activity (DNaseII) reduces antimicrobial peptide gene expression, a hallmark for immune responses in flies. Like the mammalian orthologues, Drosophila EYA features a N-terminal threonine and C-terminal tyrosine phosphatase domain. Through the generation of a series of mutant EYA fly strains, we show that the threonine phosphatase domain, but not the tyrosine phosphatase domain, is responsible for the innate immune response against DNA. A similar role for the threonine phosphatase domain in mammalian EYA4 had been surmised on the basis of in vitro studies. Furthermore EYA associates with IKKβ and full-length RELISH, and the induction of the IMD pathway-dependent antimicrobial peptide gene is independent of SO. Our data provide the first in vivo demonstration for the immune function of EYA and point to their conserved immune function in response to endogenous DNA, throughout evolution.
2011
Imler Jean-Luc, Ferrandon Dominique
[Innate immunity crowned 2011 Nobel Prize winner] Article de journal
Dans: Med Sci (Paris), vol. 27, p. 1019–24, 2011, ISSN: 0767-0974 (Print) 0767-0974 (Linking).
Liens | BibTeX | Étiquettes: *Immunity, *Nobel Prize, Biological, ferrandon, Genetic Association Studies, Humans, imler, Immunotherapy/methods/trends, Innate/genetics, M3i, Models, Molecular Targeted Therapy/trends, Seasons, Structure-Activity Relationship, Toll-Like Receptors/chemistry/genetics/isolation & purification/physiology
@article{imler_[innate_2011b,
title = {[Innate immunity crowned 2011 Nobel Prize winner]},
author = {Jean-Luc Imler and Dominique Ferrandon},
url = {http://dx.doi.org.gate1.inist.fr/10.1051/medsci/20112711020},
doi = {10.1051/medsci/20112711020},
issn = {0767-0974 (Print) 0767-0974 (Linking)},
year = {2011},
date = {2011-11-01},
journal = {Med Sci (Paris)},
volume = {27},
pages = {1019--24},
keywords = {*Immunity, *Nobel Prize, Biological, ferrandon, Genetic Association Studies, Humans, imler, Immunotherapy/methods/trends, Innate/genetics, M3i, Models, Molecular Targeted Therapy/trends, Seasons, Structure-Activity Relationship, Toll-Like Receptors/chemistry/genetics/isolation & purification/physiology},
pubstate = {published},
tppubtype = {article}
}
Chtarbanova Stanislava, Imler Jean-Luc
Immunité innée antivirale chez la drosophile Article de journal
Dans: Virologie, vol. 15, no. 5, p. 296-306, 2011, ISSN: 1267-8694.
Résumé | Liens | BibTeX | Étiquettes: *RNA Interference, antiviral immunity, Argonaute, dicer, helicase, imler, M3i, viruses
@article{Chtarbanova2011,
title = {Immunité innée antivirale chez la drosophile},
author = {Stanislava Chtarbanova and Jean-Luc Imler},
url = {http://www.jle.com/fr/revues/vir/e-docs/immunite_innee_antivirale_chez_la_drosophile_290366/article.phtml?tab=texte},
doi = {10.1684/vir.2011.0417},
issn = {1267-8694},
year = {2011},
date = {2011-10-01},
journal = {Virologie},
volume = {15},
number = {5},
pages = {296-306},
abstract = {La drosophile est utilisée depuis une quinzaine d’années comme modèle pour l’étude des mécanismes de l’immunité innée contre les infections bactériennes et fongiques. Les mécanismes de défense de cet insecte contre les infections virales sont maintenant abordés. L’interférence ARN joue un rôle essentiel dans la détection et le contrôle des virus. Ce mécanisme implique la reconnaissance des ARN double brins viraux par Dicer-2 et leur coupure pour former des petits ARN interférants (ARNsi) de 21 nucléotides. Ces ARNsi sont ensuite chargés sur l’enzyme Argonaute-2, qui inhibera spécifiquement les ARN viraux contenant une séquence complémentaire. Une réponse immunitaire inductible contribue également au contrôle des infections virales chez la drosophile. Cette réponse implique les voies de signalisation Toll et IMD, d’une part, (régulant des facteurs de transcription de la famille NF-κB) et JAK/STAT, d’autre part. On ne sait encore que peu de choses sur la nature des molécules effectrices régulées par ces voies de signalisation et sur les récepteurs qui les activent. Même si de nombreux points d’interrogation demeurent, l’intérêt du modèle drosophile pour identifier des mécanismes de défense antivirale conservés au cours de l’évolution, et impliqués dans la transmission des arbovirus par les moustiques, est aujourd’hui bien établi.},
keywords = {*RNA Interference, antiviral immunity, Argonaute, dicer, helicase, imler, M3i, viruses},
pubstate = {published},
tppubtype = {article}
}
La drosophile est utilisée depuis une quinzaine d’années comme modèle pour l’étude des mécanismes de l’immunité innée contre les infections bactériennes et fongiques. Les mécanismes de défense de cet insecte contre les infections virales sont maintenant abordés. L’interférence ARN joue un rôle essentiel dans la détection et le contrôle des virus. Ce mécanisme implique la reconnaissance des ARN double brins viraux par Dicer-2 et leur coupure pour former des petits ARN interférants (ARNsi) de 21 nucléotides. Ces ARNsi sont ensuite chargés sur l’enzyme Argonaute-2, qui inhibera spécifiquement les ARN viraux contenant une séquence complémentaire. Une réponse immunitaire inductible contribue également au contrôle des infections virales chez la drosophile. Cette réponse implique les voies de signalisation Toll et IMD, d’une part, (régulant des facteurs de transcription de la famille NF-κB) et JAK/STAT, d’autre part. On ne sait encore que peu de choses sur la nature des molécules effectrices régulées par ces voies de signalisation et sur les récepteurs qui les activent. Même si de nombreux points d’interrogation demeurent, l’intérêt du modèle drosophile pour identifier des mécanismes de défense antivirale conservés au cours de l’évolution, et impliqués dans la transmission des arbovirus par les moustiques, est aujourd’hui bien établi.
Boyer Laurent, Magoc Lorin, Dejardin Stephanie, Cappillino Michael, Paquette Nicholas, Hinault Charlotte, Charriere Guillaume M, Ip Eddie W K, Fracchia Shannon, Hennessy Elizabeth, Erturk-Hasdemir Deniz, Reichhart Jean-Marc, Silverman Neal, Lacy-Hulbert Adam, Stuart Lynda M
Pathogen-derived effectors trigger protective immunity via activation of the Rac2 enzyme and the IMD or Rip kinase signaling pathway Article de journal
Dans: Immunity, vol. 35, no. 4, p. 536–549, 2011, ISSN: 1097-4180.
Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Enzyme Activation, HEK293 Cells, Humans, M3i, rac GTP-Binding Proteins, Receptor-Interacting Protein Serine-Threonine Kinases, reichhart, Signal Transducing, Signal Transduction
@article{boyer_pathogen-derived_2011,
title = {Pathogen-derived effectors trigger protective immunity via activation of the Rac2 enzyme and the IMD or Rip kinase signaling pathway},
author = {Laurent Boyer and Lorin Magoc and Stephanie Dejardin and Michael Cappillino and Nicholas Paquette and Charlotte Hinault and Guillaume M Charriere and Eddie W K Ip and Shannon Fracchia and Elizabeth Hennessy and Deniz Erturk-Hasdemir and Jean-Marc Reichhart and Neal Silverman and Adam Lacy-Hulbert and Lynda M Stuart},
doi = {10.1016/j.immuni.2011.08.015},
issn = {1097-4180},
year = {2011},
date = {2011-10-01},
journal = {Immunity},
volume = {35},
number = {4},
pages = {536--549},
abstract = {Although infections with virulent pathogens often induce a strong inflammatory reaction, what drives the increased immune response to pathogens compared to nonpathogenic microbes is poorly understood. One possibility is that the immune system senses the level of threat from a microorganism and augments the response accordingly. Here, focusing on cytotoxic necrotizing factor 1 (CNF1), an Escherichia coli-derived effector molecule, we showed the host indirectly sensed the pathogen by monitoring for the effector that modified RhoGTPases. CNF1 modified Rac2, which then interacted with the innate immune adaptors IMD and Rip1-Rip2 in flies and mammalian cells, respectively, to drive an immune response. This response was protective and increased the ability of the host to restrict pathogen growth, thus defining a mechanism of effector-triggered immunity that contributes to how metazoans defend against microbes with pathogenic potential.},
keywords = {Adaptor Proteins, Enzyme Activation, HEK293 Cells, Humans, M3i, rac GTP-Binding Proteins, Receptor-Interacting Protein Serine-Threonine Kinases, reichhart, Signal Transducing, Signal Transduction},
pubstate = {published},
tppubtype = {article}
}
Although infections with virulent pathogens often induce a strong inflammatory reaction, what drives the increased immune response to pathogens compared to nonpathogenic microbes is poorly understood. One possibility is that the immune system senses the level of threat from a microorganism and augments the response accordingly. Here, focusing on cytotoxic necrotizing factor 1 (CNF1), an Escherichia coli-derived effector molecule, we showed the host indirectly sensed the pathogen by monitoring for the effector that modified RhoGTPases. CNF1 modified Rac2, which then interacted with the innate immune adaptors IMD and Rip1-Rip2 in flies and mammalian cells, respectively, to drive an immune response. This response was protective and increased the ability of the host to restrict pathogen growth, thus defining a mechanism of effector-triggered immunity that contributes to how metazoans defend against microbes with pathogenic potential.
Limmer Stefanie, Haller Samantha, Drenkard Eliana, Lee Janice, Yu Shen, Kocks Christine, Ausubel Frederick M, Ferrandon Dominique
Pseudomonas aeruginosa RhlR is required to neutralize the cellular immune response in a Drosophila melanogaster oral infection model Article de journal
Dans: Proc. Natl. Acad. Sci. U.S.A., vol. 108, no. 42, p. 17378–17383, 2011, ISSN: 1091-6490.
Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Bacteremia, Bacterial Proteins, Cellular, Disease Models, ferrandon, Genes, Genetically Modified, Hemolymph, Host-Pathogen Interactions, Immunity, Insect, M3i, Mutation, Oral, Pseudomonas aeruginosa, Pseudomonas Infections, Quorum Sensing, Trans-Activators, Viral, Virulence
@article{limmer_pseudomonas_2011b,
title = {Pseudomonas aeruginosa RhlR is required to neutralize the cellular immune response in a Drosophila melanogaster oral infection model},
author = {Stefanie Limmer and Samantha Haller and Eliana Drenkard and Janice Lee and Shen Yu and Christine Kocks and Frederick M Ausubel and Dominique Ferrandon},
doi = {10.1073/pnas.1114907108},
issn = {1091-6490},
year = {2011},
date = {2011-10-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {108},
number = {42},
pages = {17378--17383},
abstract = {An in-depth mechanistic understanding of microbial infection necessitates a molecular dissection of host-pathogen relationships. Both Drosophila melanogaster and Pseudomonas aeruginosa have been intensively studied. Here, we analyze the infection of D. melanogaster by P. aeruginosa by using mutants in both host and pathogen. We show that orally ingested P. aeruginosa crosses the intestinal barrier and then proliferates in the hemolymph, thereby causing the infected flies to die of bacteremia. Host defenses against ingested P. aeruginosa included an immune deficiency (IMD) response in the intestinal epithelium, systemic Toll and IMD pathway responses, and a cellular immune response controlling bacteria in the hemocoel. Although the observed cellular and intestinal immune responses appeared to act throughout the course of the infection, there was a late onset of the systemic IMD and Toll responses. In this oral infection model, P. aeruginosa PA14 did not require its type III secretion system or other well-studied virulence factors such as the two-component response regulator GacA or the protease AprA for virulence. In contrast, the quorum-sensing transcription factor RhlR, but surprisingly not LasR, played a key role in counteracting the cellular immune response against PA14, possibly at an early stage when only a few bacteria are present in the hemocoel. These results illustrate the power of studying infection from the dual perspective of host and pathogen by revealing that RhlR plays a more complex role during pathogenesis than previously appreciated.},
keywords = {Animal, Animals, Bacteremia, Bacterial Proteins, Cellular, Disease Models, ferrandon, Genes, Genetically Modified, Hemolymph, Host-Pathogen Interactions, Immunity, Insect, M3i, Mutation, Oral, Pseudomonas aeruginosa, Pseudomonas Infections, Quorum Sensing, Trans-Activators, Viral, Virulence},
pubstate = {published},
tppubtype = {article}
}
An in-depth mechanistic understanding of microbial infection necessitates a molecular dissection of host-pathogen relationships. Both Drosophila melanogaster and Pseudomonas aeruginosa have been intensively studied. Here, we analyze the infection of D. melanogaster by P. aeruginosa by using mutants in both host and pathogen. We show that orally ingested P. aeruginosa crosses the intestinal barrier and then proliferates in the hemolymph, thereby causing the infected flies to die of bacteremia. Host defenses against ingested P. aeruginosa included an immune deficiency (IMD) response in the intestinal epithelium, systemic Toll and IMD pathway responses, and a cellular immune response controlling bacteria in the hemocoel. Although the observed cellular and intestinal immune responses appeared to act throughout the course of the infection, there was a late onset of the systemic IMD and Toll responses. In this oral infection model, P. aeruginosa PA14 did not require its type III secretion system or other well-studied virulence factors such as the two-component response regulator GacA or the protease AprA for virulence. In contrast, the quorum-sensing transcription factor RhlR, but surprisingly not LasR, played a key role in counteracting the cellular immune response against PA14, possibly at an early stage when only a few bacteria are present in the hemocoel. These results illustrate the power of studying infection from the dual perspective of host and pathogen by revealing that RhlR plays a more complex role during pathogenesis than previously appreciated.
Chtarbanova Stanislava, Imler Jean-Luc
Microbial sensing by Toll receptors: a historical perspective Article de journal
Dans: Arteriosclerosis, Thrombosis, and Vascular Biology, vol. 31, no. 8, p. 1734–1738, 2011, ISSN: 1524-4636.
Résumé | Liens | BibTeX | Étiquettes: Animals, Cardiovascular Diseases, history, Host-Pathogen Interactions, Humans, imler, Immunity, Innate, M3i, Macrophages, Toll-Like Receptors
@article{chtarbanova_microbial_2011,
title = {Microbial sensing by Toll receptors: a historical perspective},
author = {Stanislava Chtarbanova and Jean-Luc Imler},
doi = {10.1161/ATVBAHA.108.179523},
issn = {1524-4636},
year = {2011},
date = {2011-08-01},
journal = {Arteriosclerosis, Thrombosis, and Vascular Biology},
volume = {31},
number = {8},
pages = {1734--1738},
abstract = {The family of Toll-like receptors plays an essential role in the induction of the immune response. These receptors sense the presence of microbial ligands and activate the nuclear factor-κB transcription factor. We review the key studies that led from the formulation of the concept of pattern recognition receptors to the characterization of Toll-like receptors, insisting on the important role played by the model organism Drosophila melanogaster and on the increasing evidence connecting these receptors to cardiovascular disease.},
keywords = {Animals, Cardiovascular Diseases, history, Host-Pathogen Interactions, Humans, imler, Immunity, Innate, M3i, Macrophages, Toll-Like Receptors},
pubstate = {published},
tppubtype = {article}
}
The family of Toll-like receptors plays an essential role in the induction of the immune response. These receptors sense the presence of microbial ligands and activate the nuclear factor-κB transcription factor. We review the key studies that led from the formulation of the concept of pattern recognition receptors to the characterization of Toll-like receptors, insisting on the important role played by the model organism Drosophila melanogaster and on the increasing evidence connecting these receptors to cardiovascular disease.
Marois Eric
The multifaceted mosquito anti-Plasmodium response Article de journal
Dans: Curr Opin Microbiol., vol. 14, no. 4, p. 429-35, 2011.
Résumé | Liens | BibTeX | Étiquettes: anti-Plasmodium response, M3i, marois
@article{E2011,
title = {The multifaceted mosquito anti-Plasmodium response},
author = {Eric Marois},
url = {http://www.ncbi.nlm.nih.gov/pubmed/21802348},
year = {2011},
date = {2011-07-27},
journal = {Curr Opin Microbiol.},
volume = {14},
number = {4},
pages = {429-35},
abstract = {Plasmodium development within its mosquito vector is an essential step in malaria transmission, as illustrated in world regions where malaria was successfully eradicated via vector control. The innate immune system of most mosquitoes is able to completely clear a Plasmodium infection, preventing parasite transmission to humans. Understanding the biological basis of this phenomenon is expected to inspire new strategies to curb malaria incidence in countries where vector control via insecticides is unpractical, or inefficient because insecticide resistance genes have spread across mosquito populations. Several aspects of mosquito biology that condition the success of the parasite in colonizing its vector begin to be understood at the molecular level, and a wealth of recently published data highlights the multifaceted nature of the mosquito response against parasite invasion. In this brief review, we attempt to provide an integrated view of the challenges faced by the parasite to successfully invade its mosquito host, and discuss the possible intervention strategies that could exploit this knowledge for the fight against human malaria.},
keywords = {anti-Plasmodium response, M3i, marois},
pubstate = {published},
tppubtype = {article}
}
Plasmodium development within its mosquito vector is an essential step in malaria transmission, as illustrated in world regions where malaria was successfully eradicated via vector control. The innate immune system of most mosquitoes is able to completely clear a Plasmodium infection, preventing parasite transmission to humans. Understanding the biological basis of this phenomenon is expected to inspire new strategies to curb malaria incidence in countries where vector control via insecticides is unpractical, or inefficient because insecticide resistance genes have spread across mosquito populations. Several aspects of mosquito biology that condition the success of the parasite in colonizing its vector begin to be understood at the molecular level, and a wealth of recently published data highlights the multifaceted nature of the mosquito response against parasite invasion. In this brief review, we attempt to provide an integrated view of the challenges faced by the parasite to successfully invade its mosquito host, and discuss the possible intervention strategies that could exploit this knowledge for the fight against human malaria.
Eleftherianos Ioannis, Won Sungyong, Chtarbanova Stanislava, Squiban Barbara, Ocorr Karen, Bodmer Rolf, Beutler Bruce, Hoffmann Jules A, Imler Jean-Luc
ATP-sensitive potassium channel (K(ATP))-dependent regulation of cardiotropic viral infections Article de journal
Dans: Proceedings of the National Academy of Sciences of the United States of America, vol. 108, no. 29, p. 12024–12029, 2011, ISSN: 1091-6490.
Résumé | Liens | BibTeX | Étiquettes: Animals, Heart, HeLa Cells, hoffmann, Humans, imler, Immunity, Immunoblotting, Inbred C57BL, Innate, KATP Channels, M3i, Mice, Nodaviridae, Pinacidil, Reverse Transcriptase Polymerase Chain Reaction, RNA Interference, Tolbutamide, Viral Load, Viremia
@article{eleftherianos_atp-sensitive_2011,
title = {ATP-sensitive potassium channel (K(ATP))-dependent regulation of cardiotropic viral infections},
author = {Ioannis Eleftherianos and Sungyong Won and Stanislava Chtarbanova and Barbara Squiban and Karen Ocorr and Rolf Bodmer and Bruce Beutler and Jules A Hoffmann and Jean-Luc Imler},
doi = {10.1073/pnas.1108926108},
issn = {1091-6490},
year = {2011},
date = {2011-07-01},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {108},
number = {29},
pages = {12024--12029},
abstract = {The effects of the cellular environment on innate immunity remain poorly characterized. Here, we show that in Drosophila ATP-sensitive potassium channels (K(ATP)) mediate resistance to a cardiotropic RNA virus, Flock House virus (FHV). FHV viral load in the heart rapidly increases in K(ATP) mutant flies, leading to increased viremia and accelerated death. The effect of K(ATP) channels is dependent on the RNA interference genes Dcr-2, AGO2, and r2d2, indicating that an activity associated with this potassium channel participates in this antiviral pathway in Drosophila. Flies treated with the K(ATP) agonist drug pinacidil are protected against FHV infection, thus demonstrating the importance of this regulation of innate immunity by the cellular environment in the heart. In mice, the Coxsackievirus B3 replicates to higher titers in the hearts of mayday mutant animals, which are deficient in the Kir6.1 subunit of K(ATP) channels, than in controls. Together, our data suggest that K(ATP) channel deregulation can have a critical impact on innate antiviral immunity in the heart.},
keywords = {Animals, Heart, HeLa Cells, hoffmann, Humans, imler, Immunity, Immunoblotting, Inbred C57BL, Innate, KATP Channels, M3i, Mice, Nodaviridae, Pinacidil, Reverse Transcriptase Polymerase Chain Reaction, RNA Interference, Tolbutamide, Viral Load, Viremia},
pubstate = {published},
tppubtype = {article}
}
The effects of the cellular environment on innate immunity remain poorly characterized. Here, we show that in Drosophila ATP-sensitive potassium channels (K(ATP)) mediate resistance to a cardiotropic RNA virus, Flock House virus (FHV). FHV viral load in the heart rapidly increases in K(ATP) mutant flies, leading to increased viremia and accelerated death. The effect of K(ATP) channels is dependent on the RNA interference genes Dcr-2, AGO2, and r2d2, indicating that an activity associated with this potassium channel participates in this antiviral pathway in Drosophila. Flies treated with the K(ATP) agonist drug pinacidil are protected against FHV infection, thus demonstrating the importance of this regulation of innate immunity by the cellular environment in the heart. In mice, the Coxsackievirus B3 replicates to higher titers in the hearts of mayday mutant animals, which are deficient in the Kir6.1 subunit of K(ATP) channels, than in controls. Together, our data suggest that K(ATP) channel deregulation can have a critical impact on innate antiviral immunity in the heart.
Limmer Stefanie, Quintin Jessica, Hetru Charles, Ferrandon Dominique
Virulence on the fly: Drosophila melanogaster as a model genetic organism to decipher host-pathogen interactions Article de journal
Dans: Curr Drug Targets, vol. 12, no. 7, p. 978–999, 2011, ISSN: 1873-5592.
Résumé | BibTeX | Étiquettes: Animal, Animals, Anti-Infective Agents, Disease Models, Drug Delivery Systems, Drug Design, Drug Resistance, ferrandon, Fungi, High-Throughput Screening Assays, Host-Pathogen Interactions, Humans, M3i, Microbial, Pseudomonas aeruginosa
@article{limmer_virulence_2011b,
title = {Virulence on the fly: Drosophila melanogaster as a model genetic organism to decipher host-pathogen interactions},
author = {Stefanie Limmer and Jessica Quintin and Charles Hetru and Dominique Ferrandon},
issn = {1873-5592},
year = {2011},
date = {2011-06-01},
journal = {Curr Drug Targets},
volume = {12},
number = {7},
pages = {978--999},
abstract = {To gain an in-depth grasp of infectious processes one has to know the specific interactions between the virulence factors of the pathogen and the host defense mechanisms. A thorough understanding is crucial for identifying potential new drug targets and designing drugs against which the pathogens might not develop resistance easily. Model organisms are a useful tool for this endeavor, thanks to the power of their genetics. Drosophila melanogaster is widely used to study host-pathogen interactions. Its basal immune response is well understood and is briefly reviewed here. Considerations relevant to choosing an adequate infection model are discussed. This review then focuses mainly on infections with two categories of pathogens, the well-studied Gram-negative bacterium Pseudomonas aeruginosa and infections by fungi of medical interest. These examples provide an overview over the current knowledge on Drosophila-pathogen interactions and illustrate the approaches that can be used to study those interactions. We also discuss the usefulness and limits of Drosophila infection models for studying specific host-pathogen interactions and high-throughput drug screening.},
keywords = {Animal, Animals, Anti-Infective Agents, Disease Models, Drug Delivery Systems, Drug Design, Drug Resistance, ferrandon, Fungi, High-Throughput Screening Assays, Host-Pathogen Interactions, Humans, M3i, Microbial, Pseudomonas aeruginosa},
pubstate = {published},
tppubtype = {article}
}
To gain an in-depth grasp of infectious processes one has to know the specific interactions between the virulence factors of the pathogen and the host defense mechanisms. A thorough understanding is crucial for identifying potential new drug targets and designing drugs against which the pathogens might not develop resistance easily. Model organisms are a useful tool for this endeavor, thanks to the power of their genetics. Drosophila melanogaster is widely used to study host-pathogen interactions. Its basal immune response is well understood and is briefly reviewed here. Considerations relevant to choosing an adequate infection model are discussed. This review then focuses mainly on infections with two categories of pathogens, the well-studied Gram-negative bacterium Pseudomonas aeruginosa and infections by fungi of medical interest. These examples provide an overview over the current knowledge on Drosophila-pathogen interactions and illustrate the approaches that can be used to study those interactions. We also discuss the usefulness and limits of Drosophila infection models for studying specific host-pathogen interactions and high-throughput drug screening.
Ogawa Michinaga, Yoshikawa Yuko, Kobayashi Taira, Mimuro Hitomi, Fukumatsu Makoto, Kiga Kotaro, Piao Zhenzi, Ashida Hiroshi, Yoshida Mitsutaka, Kakuta Shigeru, Koyama Tomohiro, Goto Yoshiyuki, Nagatake Takahiro, Nagai Shinya, Kiyono Hiroshi, Kawalec Magdalena, Reichhart Jean-Marc, Sasakawa Chihiro
A Tecpr1-dependent selective autophagy pathway targets bacterial pathogens Article de journal
Dans: Cell Host Microbe, vol. 9, no. 5, p. 376–389, 2011, ISSN: 1934-6069.
Résumé | Liens | BibTeX | Étiquettes: Animals, Autophagy, Biological, Cells, Cultured, M3i, Membrane Proteins, Mice, Microtubule-Associated Proteins, Models, Phagosomes, Protein Interaction Mapping, reichhart, Shigella, Two-Hybrid System Techniques
@article{ogawa_tecpr1-dependent_2011,
title = {A Tecpr1-dependent selective autophagy pathway targets bacterial pathogens},
author = {Michinaga Ogawa and Yuko Yoshikawa and Taira Kobayashi and Hitomi Mimuro and Makoto Fukumatsu and Kotaro Kiga and Zhenzi Piao and Hiroshi Ashida and Mitsutaka Yoshida and Shigeru Kakuta and Tomohiro Koyama and Yoshiyuki Goto and Takahiro Nagatake and Shinya Nagai and Hiroshi Kiyono and Magdalena Kawalec and Jean-Marc Reichhart and Chihiro Sasakawa},
doi = {10.1016/j.chom.2011.04.010},
issn = {1934-6069},
year = {2011},
date = {2011-05-01},
journal = {Cell Host Microbe},
volume = {9},
number = {5},
pages = {376--389},
abstract = {Selective autophagy of bacterial pathogens represents a host innate immune mechanism. Selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. In this study we identified a highly conserved Tectonin domain-containing protein, Tecpr1, as an Atg5 binding partner that colocalized with Atg5 at Shigella-containing phagophores. Tecpr1 activity is necessary for efficient autophagic targeting of bacteria, but has no effect on rapamycin- or starvation-induced canonical autophagy. Tecpr1 interacts with WIPI-2, a yeast Atg18 homolog and PI(3)P-interacting protein required for phagophore formation, and they colocalize to phagophores. Although Tecpr1-deficient mice appear normal, Tecpr1-deficient MEFs were defective for selective autophagy and supported increased intracellular multiplication of Shigella. Further, depolarized mitochondria and misfolded protein aggregates accumulated in the Tecpr1-knockout MEFs. Thus, we identify a Tecpr1-dependent pathway as important in targeting bacterial pathogens for selective autophagy.},
keywords = {Animals, Autophagy, Biological, Cells, Cultured, M3i, Membrane Proteins, Mice, Microtubule-Associated Proteins, Models, Phagosomes, Protein Interaction Mapping, reichhart, Shigella, Two-Hybrid System Techniques},
pubstate = {published},
tppubtype = {article}
}
Selective autophagy of bacterial pathogens represents a host innate immune mechanism. Selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. In this study we identified a highly conserved Tectonin domain-containing protein, Tecpr1, as an Atg5 binding partner that colocalized with Atg5 at Shigella-containing phagophores. Tecpr1 activity is necessary for efficient autophagic targeting of bacteria, but has no effect on rapamycin- or starvation-induced canonical autophagy. Tecpr1 interacts with WIPI-2, a yeast Atg18 homolog and PI(3)P-interacting protein required for phagophore formation, and they colocalize to phagophores. Although Tecpr1-deficient mice appear normal, Tecpr1-deficient MEFs were defective for selective autophagy and supported increased intracellular multiplication of Shigella. Further, depolarized mitochondria and misfolded protein aggregates accumulated in the Tecpr1-knockout MEFs. Thus, we identify a Tecpr1-dependent pathway as important in targeting bacterial pathogens for selective autophagy.
Kellenberger Christine, Leone Philippe, Coquet Laurent, Jouenne Thierry, Reichhart Jean-Marc, Roussel Alain
Structure-function analysis of grass clip serine protease involved in Drosophila Toll pathway activation Article de journal
Dans: J. Biol. Chem., vol. 286, no. 14, p. 12300–12307, 2011, ISSN: 1083-351X.
Résumé | Liens | BibTeX | Étiquettes: Animals, Catalytic Domain, Cell Line, M3i, reichhart, Serine Proteases, Signal Transduction, Structure-Activity Relationship, Toll-Like Receptors
@article{kellenberger_structure-function_2011,
title = {Structure-function analysis of grass clip serine protease involved in Drosophila Toll pathway activation},
author = {Christine Kellenberger and Philippe Leone and Laurent Coquet and Thierry Jouenne and Jean-Marc Reichhart and Alain Roussel},
doi = {10.1074/jbc.M110.182741},
issn = {1083-351X},
year = {2011},
date = {2011-04-01},
journal = {J. Biol. Chem.},
volume = {286},
number = {14},
pages = {12300--12307},
abstract = {Grass is a clip domain serine protease (SP) involved in a proteolytic cascade triggering the Toll pathway activation of Drosophila during an immune response. Epistasic studies position it downstream of the apical protease ModSP and upstream of the terminal protease Spaetzle-processing enzyme. Here, we report the crystal structure of Grass zymogen. We found that Grass displays a rather deep active site cleft comparable with that of proteases of coagulation and complement cascades. A key distinctive feature is the presence of an additional loop (75-loop) in the proximity of the activation site localized on a protruding loop. All biochemical attempts to hydrolyze the activation site of Grass failed, strongly suggesting restricted access to this region. The 75-loop is thus proposed to constitute an original mechanism to prevent spontaneous activation. A comparison of Grass with clip serine proteases of known function involved in analogous proteolytic cascades allowed us to define two groups, according to the presence of the 75-loop and the conformation of the clip domain. One group (devoid of the 75-loop) contains penultimate proteases whereas the other contains terminal proteases. Using this classification, Grass appears to be a terminal protease. This result is evaluated according to the genetic data documenting Grass function.},
keywords = {Animals, Catalytic Domain, Cell Line, M3i, reichhart, Serine Proteases, Signal Transduction, Structure-Activity Relationship, Toll-Like Receptors},
pubstate = {published},
tppubtype = {article}
}
Grass is a clip domain serine protease (SP) involved in a proteolytic cascade triggering the Toll pathway activation of Drosophila during an immune response. Epistasic studies position it downstream of the apical protease ModSP and upstream of the terminal protease Spaetzle-processing enzyme. Here, we report the crystal structure of Grass zymogen. We found that Grass displays a rather deep active site cleft comparable with that of proteases of coagulation and complement cascades. A key distinctive feature is the presence of an additional loop (75-loop) in the proximity of the activation site localized on a protruding loop. All biochemical attempts to hydrolyze the activation site of Grass failed, strongly suggesting restricted access to this region. The 75-loop is thus proposed to constitute an original mechanism to prevent spontaneous activation. A comparison of Grass with clip serine proteases of known function involved in analogous proteolytic cascades allowed us to define two groups, according to the presence of the 75-loop and the conformation of the clip domain. One group (devoid of the 75-loop) contains penultimate proteases whereas the other contains terminal proteases. Using this classification, Grass appears to be a terminal protease. This result is evaluated according to the genetic data documenting Grass function.
Aoun Richard Bou, Hetru Charles, Troxler Laurent, Doucet Daniel, Ferrandon Dominique, Matt Nicolas
Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster Article de journal
Dans: J Innate Immun, vol. 3, no. 1, p. 52–64, 2011, ISSN: 1662-8128.
Résumé | Liens | BibTeX | Étiquettes: Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis
@article{bou_aoun_analysis_2011,
title = {Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster},
author = {Richard Bou Aoun and Charles Hetru and Laurent Troxler and Daniel Doucet and Dominique Ferrandon and Nicolas Matt},
doi = {10.1159/000321554},
issn = {1662-8128},
year = {2011},
date = {2011-01-01},
journal = {J Innate Immun},
volume = {3},
number = {1},
pages = {52--64},
abstract = {Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila.},
keywords = {Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis},
pubstate = {published},
tppubtype = {article}
}
Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila.
Reichhart Jean-Marc, Gubb David, Leclerc Vincent
The Drosophila serpins: multiple functions in immunity and morphogenesis Article de journal
Dans: Meth. Enzymol., vol. 499, p. 205–225, 2011, ISSN: 1557-7988.
Résumé | Liens | BibTeX | Étiquettes: Animals, Immunity, Innate, M3i, Morphogenesis, reichhart, Serpins, Signal Transduction
@article{reichhart_drosophila_2011,
title = {The Drosophila serpins: multiple functions in immunity and morphogenesis},
author = {Jean-Marc Reichhart and David Gubb and Vincent Leclerc},
doi = {10.1016/B978-0-12-386471-0.00011-0},
issn = {1557-7988},
year = {2011},
date = {2011-01-01},
journal = {Meth. Enzymol.},
volume = {499},
pages = {205--225},
abstract = {Members of the serpin superfamily of proteins have been found in all living organisms, although rarely in bacteria or fungi. They have been extensively studied in mammals, where many rapid physiological responses are regulated by inhibitory serpins. In addition to the inhibitory serpins, a large group of noninhibitory proteins with a conserved serpin fold have also been identified in mammals. These noninhibitory proteins have a wide range of functions, from storage proteins to molecular chaperones, hormone transporters, and tumor suppressors. In contrast, until recently, very little was known about insect serpins in general, or Drosophila serpins in particular. In the last decade, however, there has been an increasing interest in the serpin biology of insects. It is becoming clear that, like in mammals, a similar wide range of physiological responses are regulated in insects and that noninhibitory serpin-fold proteins also play key roles in insect biology. Drosophila is also an important model organism that can be used to study human pathologies (among which serpinopathies or other protein conformational diseases) and mechanisms of regulation of proteolytic cascades in health or to develop strategies for control of insect pests and disease vectors. As most of our knowledge on insect serpins comes from studies on the Drosophila immune response, we survey here the Drosophila serpin literature and describe the laboratory techniques that have been developed to study serpin-regulated responses in this model genetic organism.},
keywords = {Animals, Immunity, Innate, M3i, Morphogenesis, reichhart, Serpins, Signal Transduction},
pubstate = {published},
tppubtype = {article}
}
Members of the serpin superfamily of proteins have been found in all living organisms, although rarely in bacteria or fungi. They have been extensively studied in mammals, where many rapid physiological responses are regulated by inhibitory serpins. In addition to the inhibitory serpins, a large group of noninhibitory proteins with a conserved serpin fold have also been identified in mammals. These noninhibitory proteins have a wide range of functions, from storage proteins to molecular chaperones, hormone transporters, and tumor suppressors. In contrast, until recently, very little was known about insect serpins in general, or Drosophila serpins in particular. In the last decade, however, there has been an increasing interest in the serpin biology of insects. It is becoming clear that, like in mammals, a similar wide range of physiological responses are regulated in insects and that noninhibitory serpin-fold proteins also play key roles in insect biology. Drosophila is also an important model organism that can be used to study human pathologies (among which serpinopathies or other protein conformational diseases) and mechanisms of regulation of proteolytic cascades in health or to develop strategies for control of insect pests and disease vectors. As most of our knowledge on insect serpins comes from studies on the Drosophila immune response, we survey here the Drosophila serpin literature and describe the laboratory techniques that have been developed to study serpin-regulated responses in this model genetic organism.
Meister Marie, Ferrandon Dominique
Immune cell transdifferentiation: a complex crosstalk between circulating immune cells and the haematopoietic niche Article de journal
Dans: EMBO Rep, vol. 13, p. 3–4, 2011, ISSN: 1469-3178 (Electronic) 1469-221X (Linking).
Liens | BibTeX | Étiquettes: ferrandon, M3i
@article{meister_immune_2011,
title = {Immune cell transdifferentiation: a complex crosstalk between circulating immune cells and the haematopoietic niche},
author = {Marie Meister and Dominique Ferrandon},
doi = {embor2011238 [pii] 10.1038/embor.2011.238},
issn = {1469-3178 (Electronic) 1469-221X (Linking)},
year = {2011},
date = {2011-01-01},
journal = {EMBO Rep},
volume = {13},
pages = {3--4},
keywords = {ferrandon, M3i},
pubstate = {published},
tppubtype = {article}
}
Lee Kwang-Zin, Ferrandon Dominique
Negative regulation of immune responses on the fly Article de journal
Dans: EMBO J., vol. 30, no. 6, p. 988–990, 2011, ISSN: 1460-2075.
Liens | BibTeX | Étiquettes: *Gene Expression Regulation, *Homeostasis, Animals, bacteria, Bacteria/*immunology, Biological, Drosophila melanogaster/*immunology, Drosophila Proteins/biosynthesis/metabolism, ferrandon, Gene Expression Regulation, Homeostasis, M3i, Mitogen-Activated Protein Kinases, Mitogen-Activated Protein Kinases/metabolism, Models, NF-kappa B, NF-kappa B/metabolism, ras Proteins, ras Proteins/metabolism, Receptor Protein-Tyrosine Kinases, Receptor Protein-Tyrosine Kinases/metabolism
@article{lee_negative_2011b,
title = {Negative regulation of immune responses on the fly},
author = {Kwang-Zin Lee and Dominique Ferrandon},
doi = {10.1038/emboj.2011.47},
issn = {1460-2075},
year = {2011},
date = {2011-01-01},
journal = {EMBO J.},
volume = {30},
number = {6},
pages = {988--990},
keywords = {*Gene Expression Regulation, *Homeostasis, Animals, bacteria, Bacteria/*immunology, Biological, Drosophila melanogaster/*immunology, Drosophila Proteins/biosynthesis/metabolism, ferrandon, Gene Expression Regulation, Homeostasis, M3i, Mitogen-Activated Protein Kinases, Mitogen-Activated Protein Kinases/metabolism, Models, NF-kappa B, NF-kappa B/metabolism, ras Proteins, ras Proteins/metabolism, Receptor Protein-Tyrosine Kinases, Receptor Protein-Tyrosine Kinases/metabolism},
pubstate = {published},
tppubtype = {article}
}
Nehme Nadine T, Quintin Jessica, Cho Ju Hyun, Lee Janice, Lafarge Marie-Céline, Kocks Christine, Ferrandon Dominique
Relative roles of the cellular and humoral responses in the Drosophila host defense against three gram-positive bacterial infections Article de journal
Dans: PLoS ONE, vol. 6, no. 3, p. e14743, 2011, ISSN: 1932-6203.
Résumé | Liens | BibTeX | Étiquettes: Animals, Antimicrobial Cationic Peptides, Carrier Proteins, Cell Surface, Cellular, Enterococcus faecalis, ferrandon, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, Host-Pathogen Interactions, Humoral, Immunity, Innate, M3i, Micrococcus luteus, Opsonin Proteins, Phagocytosis, Receptors, Signal Transduction, Solubility, Staphylococcus aureus
@article{nehme_relative_2011b,
title = {Relative roles of the cellular and humoral responses in the Drosophila host defense against three gram-positive bacterial infections},
author = {Nadine T Nehme and Jessica Quintin and Ju Hyun Cho and Janice Lee and Marie-Céline Lafarge and Christine Kocks and Dominique Ferrandon},
doi = {10.1371/journal.pone.0014743},
issn = {1932-6203},
year = {2011},
date = {2011-01-01},
journal = {PLoS ONE},
volume = {6},
number = {3},
pages = {e14743},
abstract = {BACKGROUND: Two NF-kappaB signaling pathways, Toll and immune deficiency (imd), are required for survival to bacterial infections in Drosophila. In response to septic injury, these pathways mediate rapid transcriptional activation of distinct sets of effector molecules, including antimicrobial peptides, which are important components of a humoral defense response. However, it is less clear to what extent macrophage-like hemocytes contribute to host defense. METHODOLOGY/PRINCIPAL FINDINGS: In order to dissect the relative importance of humoral and cellular defenses after septic injury with three different gram-positive bacteria (Micrococcus luteus, Enterococcus faecalis, Staphylococcus aureus), we used latex bead pre-injection to ablate macrophage function in flies wildtype or mutant for various Toll and imd pathway components. We found that in all three infection models a compromised phagocytic system impaired fly survival--independently of concomitant Toll or imd pathway activation. Our data failed to confirm a role of the PGRP-SA and GNBP1 Pattern Recognition Receptors for phagocytosis of S. aureus. The Drosophila scavenger receptor Eater mediates the phagocytosis by hemocytes or S2 cells of E. faecalis and S. aureus, but not of M. luteus. In the case of M. luteus and E. faecalis, but not S. aureus, decreased survival due to defective phagocytosis could be compensated for by genetically enhancing the humoral immune response. CONCLUSIONS/SIGNIFICANCE: Our results underscore the fundamental importance of both cellular and humoral mechanisms in Drosophila immunity and shed light on the balance between these two arms of host defense depending on the invading pathogen.},
keywords = {Animals, Antimicrobial Cationic Peptides, Carrier Proteins, Cell Surface, Cellular, Enterococcus faecalis, ferrandon, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, Host-Pathogen Interactions, Humoral, Immunity, Innate, M3i, Micrococcus luteus, Opsonin Proteins, Phagocytosis, Receptors, Signal Transduction, Solubility, Staphylococcus aureus},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Two NF-kappaB signaling pathways, Toll and immune deficiency (imd), are required for survival to bacterial infections in Drosophila. In response to septic injury, these pathways mediate rapid transcriptional activation of distinct sets of effector molecules, including antimicrobial peptides, which are important components of a humoral defense response. However, it is less clear to what extent macrophage-like hemocytes contribute to host defense. METHODOLOGY/PRINCIPAL FINDINGS: In order to dissect the relative importance of humoral and cellular defenses after septic injury with three different gram-positive bacteria (Micrococcus luteus, Enterococcus faecalis, Staphylococcus aureus), we used latex bead pre-injection to ablate macrophage function in flies wildtype or mutant for various Toll and imd pathway components. We found that in all three infection models a compromised phagocytic system impaired fly survival--independently of concomitant Toll or imd pathway activation. Our data failed to confirm a role of the PGRP-SA and GNBP1 Pattern Recognition Receptors for phagocytosis of S. aureus. The Drosophila scavenger receptor Eater mediates the phagocytosis by hemocytes or S2 cells of E. faecalis and S. aureus, but not of M. luteus. In the case of M. luteus and E. faecalis, but not S. aureus, decreased survival due to defective phagocytosis could be compensated for by genetically enhancing the humoral immune response. CONCLUSIONS/SIGNIFICANCE: Our results underscore the fundamental importance of both cellular and humoral mechanisms in Drosophila immunity and shed light on the balance between these two arms of host defense depending on the invading pathogen.
2010
Silverman Gary A, Whisstock James C, Bottomley Stephen P, Huntington James A, Kaiserman Dion, Luke Cliff J, Pak Stephen C, Reichhart Jean-Marc, Bird Phillip I
Serpins flex their muscle: I. Putting the clamps on proteolysis in diverse biological systems Article de journal
Dans: J. Biol. Chem., vol. 285, no. 32, p. 24299–24305, 2010, ISSN: 1083-351X.
Résumé | Liens | BibTeX | Étiquettes: Animals, Biological, Caenorhabditis elegans, Cell Death, Cell Differentiation, Cell Survival, Homeostasis, Humans, Immunity, Innate, M3i, Mice, Models, Phenotype, reichhart, Serpins, Transgenes, transgenic
@article{silverman_serpins_2010,
title = {Serpins flex their muscle: I. Putting the clamps on proteolysis in diverse biological systems},
author = {Gary A Silverman and James C Whisstock and Stephen P Bottomley and James A Huntington and Dion Kaiserman and Cliff J Luke and Stephen C Pak and Jean-Marc Reichhart and Phillip I Bird},
doi = {10.1074/jbc.R110.112771},
issn = {1083-351X},
year = {2010},
date = {2010-08-01},
journal = {J. Biol. Chem.},
volume = {285},
number = {32},
pages = {24299--24305},
abstract = {Serpins compose the largest superfamily of peptidase inhibitors and are well known as regulators of hemostasis and thrombolysis. Studies using model organisms, from plants to vertebrates, now show that serpins and their unique inhibitory mechanism and conformational flexibility are exploited to control proteolysis in molecular pathways associated with cell survival, development, and host defense. In addition, an increasing number of non-inhibitory serpins are emerging as important elements within a diversity of biological systems by serving as chaperones, hormone transporters, or anti-angiogenic factors.},
keywords = {Animals, Biological, Caenorhabditis elegans, Cell Death, Cell Differentiation, Cell Survival, Homeostasis, Humans, Immunity, Innate, M3i, Mice, Models, Phenotype, reichhart, Serpins, Transgenes, transgenic},
pubstate = {published},
tppubtype = {article}
}
Serpins compose the largest superfamily of peptidase inhibitors and are well known as regulators of hemostasis and thrombolysis. Studies using model organisms, from plants to vertebrates, now show that serpins and their unique inhibitory mechanism and conformational flexibility are exploited to control proteolysis in molecular pathways associated with cell survival, development, and host defense. In addition, an increasing number of non-inhibitory serpins are emerging as important elements within a diversity of biological systems by serving as chaperones, hormone transporters, or anti-angiogenic factors.
Whisstock James C, Silverman Gary A, Bird Phillip I, Bottomley Stephen P, Kaiserman Dion, Luke Cliff J, Pak Stephen C, Reichhart Jean-Marc, Huntington James A
Serpins flex their muscle: II. Structural insights into target peptidase recognition, polymerization, and transport functions Article de journal
Dans: J. Biol. Chem., vol. 285, no. 32, p. 24307–24312, 2010, ISSN: 1083-351X.
Résumé | Liens | BibTeX | Étiquettes: Animals, Biological, Biological Transport, Biophysics, Catalytic Domain, Hormones, Humans, Kinetics, M3i, Models, Peptide Hydrolases, Protein Binding, Protein Conformation, Protein Structure, reichhart, Serpins, Substrate Specificity, Tertiary, Thrombin
@article{whisstock_serpins_2010,
title = {Serpins flex their muscle: II. Structural insights into target peptidase recognition, polymerization, and transport functions},
author = {James C Whisstock and Gary A Silverman and Phillip I Bird and Stephen P Bottomley and Dion Kaiserman and Cliff J Luke and Stephen C Pak and Jean-Marc Reichhart and James A Huntington},
doi = {10.1074/jbc.R110.141408},
issn = {1083-351X},
year = {2010},
date = {2010-08-01},
journal = {J. Biol. Chem.},
volume = {285},
number = {32},
pages = {24307--24312},
abstract = {Inhibitory serpins are metastable proteins that undergo a substantial conformational rearrangement to covalently trap target peptidases. The serpin reactive center loop contributes a majority of the interactions that serpins make during the initial binding to target peptidases. However, structural studies on serpin-peptidase complexes reveal a broader set of contacts on the scaffold of inhibitory serpins that have substantial influence on guiding peptidase recognition. Structural and biophysical studies also reveal how aberrant serpin folding can lead to the formation of domain-swapped serpin multimers rather than the monomeric metastable state. Serpin domain swapping may therefore underlie the polymerization events characteristic of the serpinopathies. Finally, recent structural studies reveal how the serpin fold has been adapted for non-inhibitory functions such as hormone binding.},
keywords = {Animals, Biological, Biological Transport, Biophysics, Catalytic Domain, Hormones, Humans, Kinetics, M3i, Models, Peptide Hydrolases, Protein Binding, Protein Conformation, Protein Structure, reichhart, Serpins, Substrate Specificity, Tertiary, Thrombin},
pubstate = {published},
tppubtype = {article}
}
Inhibitory serpins are metastable proteins that undergo a substantial conformational rearrangement to covalently trap target peptidases. The serpin reactive center loop contributes a majority of the interactions that serpins make during the initial binding to target peptidases. However, structural studies on serpin-peptidase complexes reveal a broader set of contacts on the scaffold of inhibitory serpins that have substantial influence on guiding peptidase recognition. Structural and biophysical studies also reveal how aberrant serpin folding can lead to the formation of domain-swapped serpin multimers rather than the monomeric metastable state. Serpin domain swapping may therefore underlie the polymerization events characteristic of the serpinopathies. Finally, recent structural studies reveal how the serpin fold has been adapted for non-inhibitory functions such as hormone binding.
Rono Martin K, Whitten Miranda M, Oulad-Abdelghani M, Levashina Elena A, Marois Eric
The Major Yolk Protein Vitellogenin Interferes with the Anti-Plasmodium Response in the Malaria Mosquito Anopheles gambiae Article de journal
Dans: PLoS Biol., vol. 10, no. 7, p. e1000434, 2010.
Résumé | Liens | BibTeX | Étiquettes: anti-Plasmodium response, M3i, marois, vittelogenin
@article{MK2010,
title = {The Major Yolk Protein Vitellogenin Interferes with the Anti-Plasmodium Response in the Malaria Mosquito Anopheles gambiae},
author = {Martin K Rono and Miranda M Whitten and M Oulad-Abdelghani and Elena A Levashina and Eric Marois},
url = {http://www.ncbi.nlm.nih.gov/pubmed/20652016},
year = {2010},
date = {2010-07-20},
journal = {PLoS Biol.},
volume = {10},
number = {7},
pages = {e1000434},
abstract = {When taking a blood meal on a person infected with malaria, female Anopheles gambiae mosquitoes, the major vector of human malaria, acquire nutrients that will activate egg development (oogenesis) in their ovaries. Simultaneously, they infect themselves with the malaria parasite. On traversing the mosquito midgut epithelium, invading Plasmodium ookinetes are met with a potent innate immune response predominantly controlled by mosquito blood cells. Whether the concomitant processes of mosquito reproduction and immunity affect each other remains controversial. Here, we show that proteins that deliver nutrients to maturing mosquito oocytes interfere with the antiparasitic response. Lipophorin (Lp) and vitellogenin (Vg), two nutrient transport proteins, reduce the parasite-killing efficiency of the antiparasitic factor TEP1. In the absence of either nutrient transport protein, TEP1 binding to the ookinete surface becomes more efficient. We also show that Lp is required for the normal expression of Vg, and for later Plasmodium development at the oocyst stage. Furthermore, our results uncover an inhibitory role of the Cactus/REL1/REL2 signaling cassette in the expression of Vg, but not of Lp. We reveal molecular links that connect reproduction and immunity at several levels and provide a molecular basis for a long-suspected trade-off between these two processes.},
keywords = {anti-Plasmodium response, M3i, marois, vittelogenin},
pubstate = {published},
tppubtype = {article}
}
When taking a blood meal on a person infected with malaria, female Anopheles gambiae mosquitoes, the major vector of human malaria, acquire nutrients that will activate egg development (oogenesis) in their ovaries. Simultaneously, they infect themselves with the malaria parasite. On traversing the mosquito midgut epithelium, invading Plasmodium ookinetes are met with a potent innate immune response predominantly controlled by mosquito blood cells. Whether the concomitant processes of mosquito reproduction and immunity affect each other remains controversial. Here, we show that proteins that deliver nutrients to maturing mosquito oocytes interfere with the antiparasitic response. Lipophorin (Lp) and vitellogenin (Vg), two nutrient transport proteins, reduce the parasite-killing efficiency of the antiparasitic factor TEP1. In the absence of either nutrient transport protein, TEP1 binding to the ookinete surface becomes more efficient. We also show that Lp is required for the normal expression of Vg, and for later Plasmodium development at the oocyst stage. Furthermore, our results uncover an inhibitory role of the Cactus/REL1/REL2 signaling cassette in the expression of Vg, but not of Lp. We reveal molecular links that connect reproduction and immunity at several levels and provide a molecular basis for a long-suspected trade-off between these two processes.
Matskevich Alexey A, Quintin Jessica, Ferrandon Dominique
The Drosophila PRR GNBP3 assembles effector complexes involved in antifungal defenses independently of its Toll-pathway activation function Article de journal
Dans: Eur. J. Immunol., vol. 40, no. 5, p. 1244–1254, 2010, ISSN: 1521-4141.
Résumé | Liens | BibTeX | Étiquettes: Agglutination, Animals, Beauveria, Beauveria/immunology, Candida albicans, Candida albicans/immunology, Carrier Proteins, Carrier Proteins/*immunology/pharmacology, Drosophila melanogaster/*immunology/microbiology, Drosophila Proteins/*immunology/pharmacology/physiology, Enzyme Activation, ferrandon, Fungal, Fungi, Fungi/*immunology, Hemolymph, Hemolymph/immunology, M3i, Melanins, Melanins/*physiology, Monophenol Monooxygenase, Monophenol Monooxygenase/physiology, Multiprotein Complexes, Multiprotein Complexes/physiology, Recombinant Fusion Proteins, Recombinant Fusion Proteins/pharmacology, Serpins, Serpins/physiology, Spores, Toll-Like Receptors, Toll-Like Receptors/immunology
@article{matskevich_drosophila_2010b,
title = {The Drosophila PRR GNBP3 assembles effector complexes involved in antifungal defenses independently of its Toll-pathway activation function},
author = {Alexey A Matskevich and Jessica Quintin and Dominique Ferrandon},
doi = {10.1002/eji.200940164},
issn = {1521-4141},
year = {2010},
date = {2010-05-01},
journal = {Eur. J. Immunol.},
volume = {40},
number = {5},
pages = {1244--1254},
abstract = {The Drosophila Toll-signaling pathway controls the systemic antifungal host response. Gram-negative binding protein 3 (GNBP3), a member of the beta-glucan recognition protein family senses fungal infections and activates this pathway. A second detection system perceives the activity of proteolytic fungal virulence factors and redundantly activates Toll. GNBP3(hades) mutant flies succumb more rapidly to Candida albicans and to entomopathogenic fungal infections than WT flies, despite normal triggering of the Toll pathway via the virulence detection system. These observations suggest that GNBP3 triggers antifungal defenses that are not dependent on activation of the Toll pathway. Here, we show that GNBP3 agglutinates fungal cells. Furthermore, it can activate melanization in a Toll-independent manner. Melanization is likely to be an essential defense against some fungal infections given that the entomopathogenic fungus Beauveria bassiana inhibits the activity of the main melanization enzymes, the phenol oxidases. Finally, we show that GNBP3 assembles "attack complexes", which comprise phenoloxidase and the necrotic serpin. We propose that Drosophila GNBP3 targets fungi immediately at the inception of the infection by bringing effector molecules in direct contact with the invading microorganisms.},
keywords = {Agglutination, Animals, Beauveria, Beauveria/immunology, Candida albicans, Candida albicans/immunology, Carrier Proteins, Carrier Proteins/*immunology/pharmacology, Drosophila melanogaster/*immunology/microbiology, Drosophila Proteins/*immunology/pharmacology/physiology, Enzyme Activation, ferrandon, Fungal, Fungi, Fungi/*immunology, Hemolymph, Hemolymph/immunology, M3i, Melanins, Melanins/*physiology, Monophenol Monooxygenase, Monophenol Monooxygenase/physiology, Multiprotein Complexes, Multiprotein Complexes/physiology, Recombinant Fusion Proteins, Recombinant Fusion Proteins/pharmacology, Serpins, Serpins/physiology, Spores, Toll-Like Receptors, Toll-Like Receptors/immunology},
pubstate = {published},
tppubtype = {article}
}
The Drosophila Toll-signaling pathway controls the systemic antifungal host response. Gram-negative binding protein 3 (GNBP3), a member of the beta-glucan recognition protein family senses fungal infections and activates this pathway. A second detection system perceives the activity of proteolytic fungal virulence factors and redundantly activates Toll. GNBP3(hades) mutant flies succumb more rapidly to Candida albicans and to entomopathogenic fungal infections than WT flies, despite normal triggering of the Toll pathway via the virulence detection system. These observations suggest that GNBP3 triggers antifungal defenses that are not dependent on activation of the Toll pathway. Here, we show that GNBP3 agglutinates fungal cells. Furthermore, it can activate melanization in a Toll-independent manner. Melanization is likely to be an essential defense against some fungal infections given that the entomopathogenic fungus Beauveria bassiana inhibits the activity of the main melanization enzymes, the phenol oxidases. Finally, we show that GNBP3 assembles "attack complexes", which comprise phenoloxidase and the necrotic serpin. We propose that Drosophila GNBP3 targets fungi immediately at the inception of the infection by bringing effector molecules in direct contact with the invading microorganisms.
Garcia Alvaro Baeza, Pierce Raymond J, Gourbal Benjamin, Werkmeister Elisabeth, Colinet Dominique, Reichhart Jean-Marc, Dissous Colette, Coustau Christine
Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni Article de journal
Dans: PLoS Pathog., vol. 6, no. 9, p. e1001115, 2010, ISSN: 1553-7374.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western
@article{baeza_garcia_involvement_2010,
title = {Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni},
author = {Alvaro Baeza Garcia and Raymond J Pierce and Benjamin Gourbal and Elisabeth Werkmeister and Dominique Colinet and Jean-Marc Reichhart and Colette Dissous and Christine Coustau},
doi = {10.1371/journal.ppat.1001115},
issn = {1553-7374},
year = {2010},
date = {2010-01-01},
journal = {PLoS Pathog.},
volume = {6},
number = {9},
pages = {e1001115},
abstract = {We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions.},
keywords = {Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western},
pubstate = {published},
tppubtype = {article}
}
We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions.
Paquette Nicholas, Broemer Meike, Aggarwal Kamna, Chen Li, Husson Marie, Ertürk-Hasdemir Deniz, Reichhart Jean-Marc, Meier Pascal, Silverman Neal
Caspase-mediated cleavage, IAP binding, and ubiquitination: linking three mechanisms crucial for Drosophila NF-kappaB signaling Article de journal
Dans: Mol. Cell, vol. 37, no. 2, p. 172–182, 2010, ISSN: 1097-4164.
Résumé | Liens | BibTeX | Étiquettes: Alleles, Amino Acid Motifs, Animals, Biological, Caspases, Inhibitor of Apoptosis Proteins, M3i, MAP Kinase Kinase Kinases, Models, NF-kappa B, reichhart, Sequence Alignment, Signal Transduction, Ubiquitin-Protein Ligases, Ubiquitination
@article{paquette_caspase-mediated_2010,
title = {Caspase-mediated cleavage, IAP binding, and ubiquitination: linking three mechanisms crucial for Drosophila NF-kappaB signaling},
author = {Nicholas Paquette and Meike Broemer and Kamna Aggarwal and Li Chen and Marie Husson and Deniz Ertürk-Hasdemir and Jean-Marc Reichhart and Pascal Meier and Neal Silverman},
doi = {10.1016/j.molcel.2009.12.036},
issn = {1097-4164},
year = {2010},
date = {2010-01-01},
journal = {Mol. Cell},
volume = {37},
number = {2},
pages = {172--182},
abstract = {Innate immune responses are critical for the immediate protection against microbial infection. In Drosophila, infection leads to the rapid and robust production of antimicrobial peptides through two NF-kappaB signaling pathways-IMD and Toll. The IMD pathway is triggered by DAP-type peptidoglycan, common to most Gram-negative bacteria. Signaling downstream from the peptidoglycan receptors is thought to involve K63 ubiquitination and caspase-mediated cleavage, but the molecular mechanisms remain obscure. We now show that PGN stimulation causes caspase-mediated cleavage of the imd protein, exposing a highly conserved IAP-binding motif (IBM) at its neo-N terminus. A functional IBM is required for the association of cleaved IMD with the ubiquitin E3-ligase DIAP2. Through its association with DIAP2, IMD is rapidly conjugated with K63-linked polyubiquitin chains. These results mechanistically connect caspase-mediated cleavage and K63 ubiquitination in immune-induced NF-kappaB signaling.},
keywords = {Alleles, Amino Acid Motifs, Animals, Biological, Caspases, Inhibitor of Apoptosis Proteins, M3i, MAP Kinase Kinase Kinases, Models, NF-kappa B, reichhart, Sequence Alignment, Signal Transduction, Ubiquitin-Protein Ligases, Ubiquitination},
pubstate = {published},
tppubtype = {article}
}
Innate immune responses are critical for the immediate protection against microbial infection. In Drosophila, infection leads to the rapid and robust production of antimicrobial peptides through two NF-kappaB signaling pathways-IMD and Toll. The IMD pathway is triggered by DAP-type peptidoglycan, common to most Gram-negative bacteria. Signaling downstream from the peptidoglycan receptors is thought to involve K63 ubiquitination and caspase-mediated cleavage, but the molecular mechanisms remain obscure. We now show that PGN stimulation causes caspase-mediated cleavage of the imd protein, exposing a highly conserved IAP-binding motif (IBM) at its neo-N terminus. A functional IBM is required for the association of cleaved IMD with the ubiquitin E3-ligase DIAP2. Through its association with DIAP2, IMD is rapidly conjugated with K63-linked polyubiquitin chains. These results mechanistically connect caspase-mediated cleavage and K63 ubiquitination in immune-induced NF-kappaB signaling.
Pospisilik Andrew J, Schramek Daniel, Schnidar Harald, Cronin Shane J F, Nehme Nadine T, Zhang Xiaoyun, Knauf Claude, Cani Patrice D, Aumayr Karin, Todoric Jelena, Bayer Martina, Haschemi Arvand, Puviindran Vijitha, Tar Krisztina, Orthofer Michael, Neely Gregory G, Dietzl Georg, Manoukian Armen, Funovics Martin, Prager Gerhard, Wagner Oswald, Ferrandon Dominique, Aberger Fritz, Hui Chi-chung, Esterbauer Harald, Penninger Josef M
Drosophila genome-wide obesity screen reveals hedgehog as a determinant of brown versus white adipose cell fate Article de journal
Dans: Cell, vol. 140, no. 1, p. 148–160, 2010, ISSN: 1097-4172.
Résumé | Liens | BibTeX | Étiquettes: Adipocytes, Adipogenesis, Animals, Brown, Brown/metabolism, Cyclic AMP, Cyclic AMP/metabolism, Drosophila Proteins/*metabolism, ferrandon, Glucocorticoids, Glucocorticoids/metabolism, Hedgehog Proteins, Hedgehog Proteins/*metabolism, Humans, Knockout, M3i, Mice, Muscle Cells, Muscle Cells/metabolism, Obesity, Obesity/*genetics, Repressor Proteins, Repressor Proteins/genetics, White, White/metabolism
@article{pospisilik_drosophila_2010b,
title = {Drosophila genome-wide obesity screen reveals hedgehog as a determinant of brown versus white adipose cell fate},
author = {Andrew J Pospisilik and Daniel Schramek and Harald Schnidar and Shane J F Cronin and Nadine T Nehme and Xiaoyun Zhang and Claude Knauf and Patrice D Cani and Karin Aumayr and Jelena Todoric and Martina Bayer and Arvand Haschemi and Vijitha Puviindran and Krisztina Tar and Michael Orthofer and Gregory G Neely and Georg Dietzl and Armen Manoukian and Martin Funovics and Gerhard Prager and Oswald Wagner and Dominique Ferrandon and Fritz Aberger and Chi-chung Hui and Harald Esterbauer and Josef M Penninger},
doi = {10.1016/j.cell.2009.12.027},
issn = {1097-4172},
year = {2010},
date = {2010-01-01},
journal = {Cell},
volume = {140},
number = {1},
pages = {148--160},
abstract = {Over 1 billion people are estimated to be overweight, placing them at risk for diabetes, cardiovascular disease, and cancer. We performed a systems-level genetic dissection of adiposity regulation using genome-wide RNAi screening in adult Drosophila. As a follow-up, the resulting approximately 500 candidate obesity genes were functionally classified using muscle-, oenocyte-, fat-body-, and neuronal-specific knockdown in vivo and revealed hedgehog signaling as the top-scoring fat-body-specific pathway. To extrapolate these findings into mammals, we generated fat-specific hedgehog-activation mutant mice. Intriguingly, these mice displayed near total loss of white, but not brown, fat compartments. Mechanistically, activation of hedgehog signaling irreversibly blocked differentiation of white adipocytes through direct, coordinate modulation of early adipogenic factors. These findings identify a role for hedgehog signaling in white/brown adipocyte determination and link in vivo RNAi-based scanning of the Drosophila genome to regulation of adipocyte cell fate in mammals.},
keywords = {Adipocytes, Adipogenesis, Animals, Brown, Brown/metabolism, Cyclic AMP, Cyclic AMP/metabolism, Drosophila Proteins/*metabolism, ferrandon, Glucocorticoids, Glucocorticoids/metabolism, Hedgehog Proteins, Hedgehog Proteins/*metabolism, Humans, Knockout, M3i, Mice, Muscle Cells, Muscle Cells/metabolism, Obesity, Obesity/*genetics, Repressor Proteins, Repressor Proteins/genetics, White, White/metabolism},
pubstate = {published},
tppubtype = {article}
}
Over 1 billion people are estimated to be overweight, placing them at risk for diabetes, cardiovascular disease, and cancer. We performed a systems-level genetic dissection of adiposity regulation using genome-wide RNAi screening in adult Drosophila. As a follow-up, the resulting approximately 500 candidate obesity genes were functionally classified using muscle-, oenocyte-, fat-body-, and neuronal-specific knockdown in vivo and revealed hedgehog signaling as the top-scoring fat-body-specific pathway. To extrapolate these findings into mammals, we generated fat-specific hedgehog-activation mutant mice. Intriguingly, these mice displayed near total loss of white, but not brown, fat compartments. Mechanistically, activation of hedgehog signaling irreversibly blocked differentiation of white adipocytes through direct, coordinate modulation of early adipogenic factors. These findings identify a role for hedgehog signaling in white/brown adipocyte determination and link in vivo RNAi-based scanning of the Drosophila genome to regulation of adipocyte cell fate in mammals.
2009
Shia Alice K H, Glittenberg Marcus, Thompson Gavin, Weber Alexander N R, Reichhart Jean-Marc, Ligoxygakis Petros
Toll-dependent antimicrobial responses in Drosophila larval fat body require Spätzle secreted by haemocytes Article de journal
Dans: J. Cell. Sci., vol. 122, no. Pt 24, p. 4505–4515, 2009, ISSN: 1477-9137.
Résumé | Liens | BibTeX | Étiquettes: Animals, Enterococcus faecalis, Escherichia coli, Fat Body, Hemocytes, Larva, M3i, reichhart, Toll-Like Receptors
@article{shia_toll-dependent_2009,
title = {Toll-dependent antimicrobial responses in Drosophila larval fat body require Spätzle secreted by haemocytes},
author = {Alice K H Shia and Marcus Glittenberg and Gavin Thompson and Alexander N R Weber and Jean-Marc Reichhart and Petros Ligoxygakis},
doi = {10.1242/jcs.049155},
issn = {1477-9137},
year = {2009},
date = {2009-12-01},
journal = {J. Cell. Sci.},
volume = {122},
number = {Pt 24},
pages = {4505--4515},
abstract = {In Drosophila, the humoral response characterised by the synthesis of antimicrobial peptides (AMPs) in the fat body (the equivalent of the mammalian liver) and the cellular response mediated by haemocytes (blood cells) engaged in phagocytosis represent two major reactions that counter pathogens. Although considerable analysis has permitted the elucidation of mechanisms pertaining to the two responses individually, the mechanism of their coordination has been unclear. To characterise the signals with which infection might be communicated between blood cells and fat body, we ablated circulating haemocytes and defined the parameters of AMP gene activation in larvae. We found that targeted ablation of blood cells influenced the levels of AMP gene expression in the fat body following both septic injury and oral infection. Expression of the AMP gene drosomycin (a Toll target) was blocked when expression of the Toll ligand Spätzle was knocked down in haemocytes. These results show that in larvae, integration of the two responses in a systemic reaction depend on the production of a cytokine (spz), a process that strongly parallels the mammalian immune response.},
keywords = {Animals, Enterococcus faecalis, Escherichia coli, Fat Body, Hemocytes, Larva, M3i, reichhart, Toll-Like Receptors},
pubstate = {published},
tppubtype = {article}
}
In Drosophila, the humoral response characterised by the synthesis of antimicrobial peptides (AMPs) in the fat body (the equivalent of the mammalian liver) and the cellular response mediated by haemocytes (blood cells) engaged in phagocytosis represent two major reactions that counter pathogens. Although considerable analysis has permitted the elucidation of mechanisms pertaining to the two responses individually, the mechanism of their coordination has been unclear. To characterise the signals with which infection might be communicated between blood cells and fat body, we ablated circulating haemocytes and defined the parameters of AMP gene activation in larvae. We found that targeted ablation of blood cells influenced the levels of AMP gene expression in the fat body following both septic injury and oral infection. Expression of the AMP gene drosomycin (a Toll target) was blocked when expression of the Toll ligand Spätzle was knocked down in haemocytes. These results show that in larvae, integration of the two responses in a systemic reaction depend on the production of a cytokine (spz), a process that strongly parallels the mammalian immune response.
Hetru Charles, Hoffmann Jules A
NF-kappaB in the immune response of Drosophila Article de journal
Dans: Cold Spring Harb Perspect Biol, vol. 1, no. 6, p. a000232, 2009, ISSN: 1943-0264.
Résumé | Liens | BibTeX | Étiquettes: Animals, bacteria, Fungi, Gene Expression Regulation, hoffmann, M3i, NF-kappa B
@article{hetru_nf-kappab_2009,
title = {NF-kappaB in the immune response of Drosophila},
author = {Charles Hetru and Jules A Hoffmann},
doi = {10.1101/cshperspect.a000232},
issn = {1943-0264},
year = {2009},
date = {2009-12-01},
journal = {Cold Spring Harb Perspect Biol},
volume = {1},
number = {6},
pages = {a000232},
abstract = {The nuclear factor kappaB (NF-kappaB) pathways play a major role in Drosophila host defense. Two recognition and signaling cascades control this immune response. The Toll pathway is activated by Gram-positive bacteria and by fungi, whereas the immune deficiency (Imd) pathway responds to Gram-negative bacterial infection. The basic mechanisms of recognition of these various types of microbial infections by the adult fly are now globally understood. Even though some elements are missing in the intracellular pathways, numerous proteins and interactions have been identified. In this article, we present a general picture of the immune functions of NF-kappaB in Drosophila with all the partners involved in recognition and in the signaling cascades.},
keywords = {Animals, bacteria, Fungi, Gene Expression Regulation, hoffmann, M3i, NF-kappa B},
pubstate = {published},
tppubtype = {article}
}
The nuclear factor kappaB (NF-kappaB) pathways play a major role in Drosophila host defense. Two recognition and signaling cascades control this immune response. The Toll pathway is activated by Gram-positive bacteria and by fungi, whereas the immune deficiency (Imd) pathway responds to Gram-negative bacterial infection. The basic mechanisms of recognition of these various types of microbial infections by the adult fly are now globally understood. Even though some elements are missing in the intracellular pathways, numerous proteins and interactions have been identified. In this article, we present a general picture of the immune functions of NF-kappaB in Drosophila with all the partners involved in recognition and in the signaling cascades.
Blandin Stéphanie A, Wang-Sattler R, Lamacchia Marina, Gagneur Julien, Lycett G, Ning Y, Levashina Elena A, Steinmetz Lars M
Dissecting the genetic basis of resistance to malaria parasites in Anopheles gambiae Article de journal
Dans: Science, vol. 326, no. 5949, p. 147-50, 2009.
Résumé | Liens | BibTeX | Étiquettes: blandin, M3i, TEP1
@article{SA2009,
title = {Dissecting the genetic basis of resistance to malaria parasites in Anopheles gambiae},
author = {Stéphanie A Blandin and R Wang-Sattler and Marina Lamacchia and Julien Gagneur and G Lycett and Y Ning and Elena A Levashina and Lars M Steinmetz},
url = {http://www.ncbi.nlm.nih.gov/pubmed/19797663},
year = {2009},
date = {2009-10-02},
journal = {Science},
volume = {326},
number = {5949},
pages = {147-50},
abstract = {The ability of Anopheles gambiae mosquitoes to transmit Plasmodium parasites is highly variable between individuals. However, the genetic basis of this variability has remained unknown. We combined genome-wide mapping and reciprocal allele-specific RNA interference (rasRNAi) to identify the genomic locus that confers resistance to malaria parasites and demonstrated that polymorphisms in a single gene encoding the antiparasitic thioester-containing protein 1 (TEP1) explain a substantial part of the variability in parasite killing. The link between TEP1 alleles and resistance to malaria may offer new tools for controlling malaria transmission. The successful application of rasRNAi in Anopheles suggests that it could also be applied to other organisms where RNAi is feasible to dissect complex phenotypes to the level of individual quantitative trait alleles.},
keywords = {blandin, M3i, TEP1},
pubstate = {published},
tppubtype = {article}
}
The ability of Anopheles gambiae mosquitoes to transmit Plasmodium parasites is highly variable between individuals. However, the genetic basis of this variability has remained unknown. We combined genome-wide mapping and reciprocal allele-specific RNA interference (rasRNAi) to identify the genomic locus that confers resistance to malaria parasites and demonstrated that polymorphisms in a single gene encoding the antiparasitic thioester-containing protein 1 (TEP1) explain a substantial part of the variability in parasite killing. The link between TEP1 alleles and resistance to malaria may offer new tools for controlling malaria transmission. The successful application of rasRNAi in Anopheles suggests that it could also be applied to other organisms where RNAi is feasible to dissect complex phenotypes to the level of individual quantitative trait alleles.
Mishima Yumiko, Quintin Jessica, Aimanianda Vishukumar, Kellenberger Christine, Coste Franck, Clavaud Cecile, Hetru Charles, Hoffmann Jules A, Latgé Jean-Paul, Ferrandon Dominique, Roussel Alain
The N-terminal domain of Drosophila Gram-negative binding protein 3 (GNBP3) defines a novel family of fungal pattern recognition receptors Article de journal
Dans: J. Biol. Chem., vol. 284, no. 42, p. 28687–28697, 2009, ISSN: 1083-351X.
Résumé | Liens | BibTeX | Étiquettes: Animals, beta-Glucans, Bombyx, Carrier Proteins, Crystallography, ferrandon, Fungal Proteins, Hemolymph, hoffmann, ligands, M3i, Molecular Conformation, Mutagenesis, Polysaccharides, Protein Structure, Secondary, Tertiary, X-Ray
@article{mishima_n-terminal_2009,
title = {The N-terminal domain of Drosophila Gram-negative binding protein 3 (GNBP3) defines a novel family of fungal pattern recognition receptors},
author = {Yumiko Mishima and Jessica Quintin and Vishukumar Aimanianda and Christine Kellenberger and Franck Coste and Cecile Clavaud and Charles Hetru and Jules A Hoffmann and Jean-Paul Latgé and Dominique Ferrandon and Alain Roussel},
doi = {10.1074/jbc.M109.034587},
issn = {1083-351X},
year = {2009},
date = {2009-10-01},
journal = {J. Biol. Chem.},
volume = {284},
number = {42},
pages = {28687--28697},
abstract = {Gram-negative binding protein 3 (GNBP3), a pattern recognition receptor that circulates in the hemolymph of Drosophila, is responsible for sensing fungal infection and triggering Toll pathway activation. Here, we report that GNBP3 N-terminal domain binds to fungi upon identifying long chains of beta-1,3-glucans in the fungal cell wall as a major ligand. Interestingly, this domain fails to interact strongly with short oligosaccharides. The crystal structure of GNBP3-Nter reveals an immunoglobulin-like fold in which the glucan binding site is masked by a loop that is highly conserved among glucan-binding proteins identified in several insect orders. Structure-based mutagenesis experiments reveal an essential role for this occluding loop in discriminating between short and long polysaccharides. The displacement of the occluding loop is necessary for binding and could explain the specificity of the interaction with long chain structured polysaccharides. This represents a novel mechanism for beta-glucan recognition.},
keywords = {Animals, beta-Glucans, Bombyx, Carrier Proteins, Crystallography, ferrandon, Fungal Proteins, Hemolymph, hoffmann, ligands, M3i, Molecular Conformation, Mutagenesis, Polysaccharides, Protein Structure, Secondary, Tertiary, X-Ray},
pubstate = {published},
tppubtype = {article}
}
Gram-negative binding protein 3 (GNBP3), a pattern recognition receptor that circulates in the hemolymph of Drosophila, is responsible for sensing fungal infection and triggering Toll pathway activation. Here, we report that GNBP3 N-terminal domain binds to fungi upon identifying long chains of beta-1,3-glucans in the fungal cell wall as a major ligand. Interestingly, this domain fails to interact strongly with short oligosaccharides. The crystal structure of GNBP3-Nter reveals an immunoglobulin-like fold in which the glucan binding site is masked by a loop that is highly conserved among glucan-binding proteins identified in several insect orders. Structure-based mutagenesis experiments reveal an essential role for this occluding loop in discriminating between short and long polysaccharides. The displacement of the occluding loop is necessary for binding and could explain the specificity of the interaction with long chain structured polysaccharides. This represents a novel mechanism for beta-glucan recognition.
Ferrandon Dominique
Host tolerance versus resistance and microbial virulence in the host-pathogen equation Article de journal
Dans: Cell Host Microbe, vol. 6, no. 3, p. 203–205, 2009, ISSN: 1934-6069.
Résumé | Liens | BibTeX | Étiquettes: Animals, ferrandon, Host-Pathogen Interactions, Immune Tolerance, M3i, Salmonella typhimurium, Virulence
@article{ferrandon_host_2009b,
title = {Host tolerance versus resistance and microbial virulence in the host-pathogen equation},
author = {Dominique Ferrandon},
doi = {10.1016/j.chom.2009.08.010},
issn = {1934-6069},
year = {2009},
date = {2009-09-01},
journal = {Cell Host Microbe},
volume = {6},
number = {3},
pages = {203--205},
abstract = {To deal with an infection, the organism resorts to nonmutually exclusive strategies: resistance, that is, neutralization or destruction of the pathogen; or tolerance, the ability to withstand damages inflicted by the pathogen or by host defense. In this issue of Cell Host & Microbe, Shinzawa et al. (2009) identify p38-mediated phagocytic encapsulation as a potential tolerance mechanism.},
keywords = {Animals, ferrandon, Host-Pathogen Interactions, Immune Tolerance, M3i, Salmonella typhimurium, Virulence},
pubstate = {published},
tppubtype = {article}
}
To deal with an infection, the organism resorts to nonmutually exclusive strategies: resistance, that is, neutralization or destruction of the pathogen; or tolerance, the ability to withstand damages inflicted by the pathogen or by host defense. In this issue of Cell Host & Microbe, Shinzawa et al. (2009) identify p38-mediated phagocytic encapsulation as a potential tolerance mechanism.
Fraiture Malou, Baxter Richard H G, Steinert Stefanie, Chelliah Yogarany, Frolet Cécile, Quispe-Tintaya Wilber, Hoffmann Jules A, Blandin Stéphanie A, Levashina Elena A
Two mosquito LRR proteins function as complement control factors in the TEP1-mediated killing of Plasmodium Article de journal
Dans: Cell Host Microbe, vol. 5, no. 3, p. 273–284, 2009, ISSN: 1934-6069.
Résumé | Liens | BibTeX | Étiquettes: Animals, Anopheles, APL1, Biological, blandin, Complement System Proteins, Hemolymph, hoffmann, Immunologic Factors, LRIM1, M3i, Models, Plasmodium, Protein Binding, Proteins, TEP1
@article{fraiture_two_2009,
title = {Two mosquito LRR proteins function as complement control factors in the TEP1-mediated killing of Plasmodium},
author = {Malou Fraiture and Richard H G Baxter and Stefanie Steinert and Yogarany Chelliah and Cécile Frolet and Wilber Quispe-Tintaya and Jules A Hoffmann and Stéphanie A Blandin and Elena A Levashina},
doi = {10.1016/j.chom.2009.01.005},
issn = {1934-6069},
year = {2009},
date = {2009-03-01},
journal = {Cell Host Microbe},
volume = {5},
number = {3},
pages = {273--284},
abstract = {Plasmodium development within Anopheles mosquitoes is a vulnerable step in the parasite transmission cycle, and targeting this step represents a promising strategy for malaria control. The thioester-containing complement-like protein TEP1 and two leucine-rich repeat (LRR) proteins, LRIM1 and APL1, have been identified as major mosquito factors that regulate parasite loads. Here, we show that LRIM1 and APL1 are required for binding of TEP1 to parasites. RNAi silencing of the LRR-encoding genes results in deposition of TEP1 on Anopheles tissues, thereby depleting TEP1 from circulation in the hemolymph and impeding its binding to Plasmodium. LRIM1 and APL1 not only stabilize circulating TEP1, they also stabilize each other prior to their interaction with TEP1. Our results indicate that three major antiparasitic factors in mosquitoes jointly function as a complement-like system in parasite killing, and they reveal a role for LRR proteins as complement control factors.},
keywords = {Animals, Anopheles, APL1, Biological, blandin, Complement System Proteins, Hemolymph, hoffmann, Immunologic Factors, LRIM1, M3i, Models, Plasmodium, Protein Binding, Proteins, TEP1},
pubstate = {published},
tppubtype = {article}
}
Plasmodium development within Anopheles mosquitoes is a vulnerable step in the parasite transmission cycle, and targeting this step represents a promising strategy for malaria control. The thioester-containing complement-like protein TEP1 and two leucine-rich repeat (LRR) proteins, LRIM1 and APL1, have been identified as major mosquito factors that regulate parasite loads. Here, we show that LRIM1 and APL1 are required for binding of TEP1 to parasites. RNAi silencing of the LRR-encoding genes results in deposition of TEP1 on Anopheles tissues, thereby depleting TEP1 from circulation in the hemolymph and impeding its binding to Plasmodium. LRIM1 and APL1 not only stabilize circulating TEP1, they also stabilize each other prior to their interaction with TEP1. Our results indicate that three major antiparasitic factors in mosquitoes jointly function as a complement-like system in parasite killing, and they reveal a role for LRR proteins as complement control factors.
Kemp Cordula, Imler Jean-Luc
Antiviral immunity in drosophila Article de journal
Dans: Current Opinion in Immunology, vol. 21, no. 1, p. 3–9, 2009, ISSN: 1879-0372.
Résumé | Liens | BibTeX | Étiquettes: Animals, Argonaute Proteins, Caspases, DEAD-box RNA Helicases, Evolution, Gene Expression Regulation, Host-Pathogen Interactions, imler, M3i, Membrane Proteins, Molecular, Nuclear Proteins, Ribonuclease III, RNA, RNA Helicases, RNA Interference, RNA Virus Infections, RNA Viruses, RNA-Induced Silencing Complex, Viral, Virulence
@article{kemp_antiviral_2009,
title = {Antiviral immunity in drosophila},
author = {Cordula Kemp and Jean-Luc Imler},
doi = {10.1016/j.coi.2009.01.007},
issn = {1879-0372},
year = {2009},
date = {2009-02-01},
journal = {Current Opinion in Immunology},
volume = {21},
number = {1},
pages = {3--9},
abstract = {Genetic analysis of the drosophila antiviral response indicates that RNA interference plays a major role. This contrasts with the situation in mammals, where interferon-induced responses mediate innate antiviral host-defense. An inducible response also contributes to antiviral immunity in drosophila, and similarities in the sensing and signaling of viral infection are becoming apparent between drosophila and mammals. In particular, DExD/H box helicases appear to play a crucial role in the cytosolic detection of viral RNAs in flies and mammals.},
keywords = {Animals, Argonaute Proteins, Caspases, DEAD-box RNA Helicases, Evolution, Gene Expression Regulation, Host-Pathogen Interactions, imler, M3i, Membrane Proteins, Molecular, Nuclear Proteins, Ribonuclease III, RNA, RNA Helicases, RNA Interference, RNA Virus Infections, RNA Viruses, RNA-Induced Silencing Complex, Viral, Virulence},
pubstate = {published},
tppubtype = {article}
}
Genetic analysis of the drosophila antiviral response indicates that RNA interference plays a major role. This contrasts with the situation in mammals, where interferon-induced responses mediate innate antiviral host-defense. An inducible response also contributes to antiviral immunity in drosophila, and similarities in the sensing and signaling of viral infection are becoming apparent between drosophila and mammals. In particular, DExD/H box helicases appear to play a crucial role in the cytosolic detection of viral RNAs in flies and mammals.
Berry Bassam, Deddouche Safia, Kirschner Doris, Imler Jean-Luc, Antoniewski Christophe
Viral suppressors of RNA silencing hinder exogenous and endogenous small RNA pathways in Drosophila Article de journal
Dans: PloS One, vol. 4, no. 6, p. e5866, 2009, ISSN: 1932-6203.
Résumé | Liens | BibTeX | Étiquettes: Animals, Antiviral Agents, Crosses, Double-Stranded, Gene Silencing, Genetic, Genetically Modified, Heterozygote, imler, Invertebrate, M3i, Photoreceptor Cells, Reverse Transcriptase Polymerase Chain Reaction, RNA, RNA Interference, Transgenes
@article{berry_viral_2009,
title = {Viral suppressors of RNA silencing hinder exogenous and endogenous small RNA pathways in Drosophila},
author = {Bassam Berry and Safia Deddouche and Doris Kirschner and Jean-Luc Imler and Christophe Antoniewski},
doi = {10.1371/journal.pone.0005866},
issn = {1932-6203},
year = {2009},
date = {2009-01-01},
journal = {PloS One},
volume = {4},
number = {6},
pages = {e5866},
abstract = {BACKGROUND: In plants and insects, RNA interference (RNAi) is the main responder against viruses and shapes the basis of antiviral immunity. Viruses counter this defense by expressing viral suppressors of RNAi (VSRs). While VSRs in Drosophila melanogaster were shown to inhibit RNAi through different modes of action, whether they act on other silencing pathways remained unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that expression of various plant and insect VSRs in transgenic flies does not perturb the Drosophila microRNA (miRNA) pathway; but in contrast, inhibits antiviral RNAi and the RNA silencing response triggered by inverted repeat transcripts, and injection of dsRNA or siRNA. Strikingly, these VSRs also suppressed transposon silencing by endogenous siRNAs (endo-siRNAs). CONCLUSIONS/SIGNIFICANCE: Our findings identify VSRs as tools to unravel small RNA pathways in insects and suggest a cosuppression of antiviral RNAi and endo-siRNA silencing by viruses during fly infections.},
keywords = {Animals, Antiviral Agents, Crosses, Double-Stranded, Gene Silencing, Genetic, Genetically Modified, Heterozygote, imler, Invertebrate, M3i, Photoreceptor Cells, Reverse Transcriptase Polymerase Chain Reaction, RNA, RNA Interference, Transgenes},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: In plants and insects, RNA interference (RNAi) is the main responder against viruses and shapes the basis of antiviral immunity. Viruses counter this defense by expressing viral suppressors of RNAi (VSRs). While VSRs in Drosophila melanogaster were shown to inhibit RNAi through different modes of action, whether they act on other silencing pathways remained unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that expression of various plant and insect VSRs in transgenic flies does not perturb the Drosophila microRNA (miRNA) pathway; but in contrast, inhibits antiviral RNAi and the RNA silencing response triggered by inverted repeat transcripts, and injection of dsRNA or siRNA. Strikingly, these VSRs also suppressed transposon silencing by endogenous siRNAs (endo-siRNAs). CONCLUSIONS/SIGNIFICANCE: Our findings identify VSRs as tools to unravel small RNA pathways in insects and suggest a cosuppression of antiviral RNAi and endo-siRNA silencing by viruses during fly infections.
