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2021
Arquier Nathalie, Bjordal Marianne, Hammann Philippe, Kuhn Lauriane, Léopold Pierre
Brain adiponectin signaling controls peripheral insulin response in Drosophila Article de journal
Dans: Nature Communications, vol. 12, no. 1, p. 5633, 2021, ISSN: 2041-1723.
Résumé | Liens | BibTeX | Étiquettes: Adiponectin, Animals, Brain, Cell Line, Drosophila melanogaster, Drosophila Proteins, Energy Metabolism, Genetically Modified, Hemolymph, Homeostasis, Insulin, Juvenile Hormones, Larva, Neurons, PPSE, Receptors, Signal Transduction
@article{arquier_brain_2021,
title = {Brain adiponectin signaling controls peripheral insulin response in Drosophila},
author = {Nathalie Arquier and Marianne Bjordal and Philippe Hammann and Lauriane Kuhn and Pierre Léopold},
doi = {10.1038/s41467-021-25940-6},
issn = {2041-1723},
year = {2021},
date = {2021-09-01},
journal = {Nature Communications},
volume = {12},
number = {1},
pages = {5633},
abstract = {The brain plays a key role in energy homeostasis, detecting nutrients, metabolites and circulating hormones from peripheral organs and integrating this information to control food intake and energy expenditure. Here, we show that a group of neurons in the Drosophila larval brain expresses the adiponectin receptor (AdipoR) and controls systemic growth and metabolism through insulin signaling. We identify glucose-regulated protein 78 (Grp78) as a circulating antagonist of AdipoR function produced by fat cells in response to dietary sugar. We further show that central AdipoR signaling inhibits peripheral Juvenile Hormone (JH) response, promoting insulin signaling. In conclusion, we identify a neuroendocrine axis whereby AdipoR-positive neurons control systemic insulin response.},
keywords = {Adiponectin, Animals, Brain, Cell Line, Drosophila melanogaster, Drosophila Proteins, Energy Metabolism, Genetically Modified, Hemolymph, Homeostasis, Insulin, Juvenile Hormones, Larva, Neurons, PPSE, Receptors, Signal Transduction},
pubstate = {published},
tppubtype = {article}
}
The brain plays a key role in energy homeostasis, detecting nutrients, metabolites and circulating hormones from peripheral organs and integrating this information to control food intake and energy expenditure. Here, we show that a group of neurons in the Drosophila larval brain expresses the adiponectin receptor (AdipoR) and controls systemic growth and metabolism through insulin signaling. We identify glucose-regulated protein 78 (Grp78) as a circulating antagonist of AdipoR function produced by fat cells in response to dietary sugar. We further show that central AdipoR signaling inhibits peripheral Juvenile Hormone (JH) response, promoting insulin signaling. In conclusion, we identify a neuroendocrine axis whereby AdipoR-positive neurons control systemic insulin response.
2018
Arosio Paolo, Comito Giuseppina, Orsini Francesco, Lascialfari Alessandro, Chiarugi Paola, Ménard-Moyon Cécilia, Nativi Cristina, Richichi Barbara
Conjugation of a GM3 lactone mimetic on carbon nanotubes enhances the related inhibition of melanoma-associated metastatic events Article de journal
Dans: Organic & Biomolecular Chemistry, vol. 16, no. 33, p. 6086–6095, 2018, ISSN: 1477-0539.
Résumé | Liens | BibTeX | Étiquettes: Antineoplastic Agents, Biomimetic Materials, carbon, Cell Line, G(M3) Ganglioside, Humans, I2CT, Melanoma, Models, Molecular, Molecular Conformation, Nanotubes, Neoplasm Metastasis, Team-Bianco, tumor
@article{arosio_conjugation_2018,
title = {Conjugation of a GM3 lactone mimetic on carbon nanotubes enhances the related inhibition of melanoma-associated metastatic events},
author = {Paolo Arosio and Giuseppina Comito and Francesco Orsini and Alessandro Lascialfari and Paola Chiarugi and Cécilia Ménard-Moyon and Cristina Nativi and Barbara Richichi},
doi = {10.1039/c8ob01817k},
issn = {1477-0539},
year = {2018},
date = {2018-01-01},
journal = {Organic & Biomolecular Chemistry},
volume = {16},
number = {33},
pages = {6086--6095},
abstract = {GM3-ganglioside is known to be involved in melanoma proliferation. In order to modulate metastatic-related events, we have functionalized multi-walled carbon nanotubes (MWCNTs) with multiple copies of a GM3-lactone mimetic. The MWCNTs proved to guarantee the appropriate spatial arrangement of the mimetic allowing a stronger inhibition of migration and invasiveness of human melanoma (A375) cells compared to other multivalent constructs reported before. In addition, the effect of the multivalent tubular conjugate on the inhibition of specific tyrosine kinases, which are associated with the ganglioside complexes within the membrane domains, was demonstrated. Finally, the short-term fate of the conjugate was assessed, for the first time, by means of the 1H NMR relaxometry technique by exploiting the signal arising from the CNTs.},
keywords = {Antineoplastic Agents, Biomimetic Materials, carbon, Cell Line, G(M3) Ganglioside, Humans, I2CT, Melanoma, Models, Molecular, Molecular Conformation, Nanotubes, Neoplasm Metastasis, Team-Bianco, tumor},
pubstate = {published},
tppubtype = {article}
}
GM3-ganglioside is known to be involved in melanoma proliferation. In order to modulate metastatic-related events, we have functionalized multi-walled carbon nanotubes (MWCNTs) with multiple copies of a GM3-lactone mimetic. The MWCNTs proved to guarantee the appropriate spatial arrangement of the mimetic allowing a stronger inhibition of migration and invasiveness of human melanoma (A375) cells compared to other multivalent constructs reported before. In addition, the effect of the multivalent tubular conjugate on the inhibition of specific tyrosine kinases, which are associated with the ganglioside complexes within the membrane domains, was demonstrated. Finally, the short-term fate of the conjugate was assessed, for the first time, by means of the 1H NMR relaxometry technique by exploiting the signal arising from the CNTs.
Schaeffer Evelyne, Flacher Vincent, Neuberg Patrick, Hoste Astrid, Brulefert Adrien, Fauny Jean-Daniel, Wagner Alain, Mueller Christopher G
Inhibition of dengue virus infection by mannoside glycolipid conjugates Article de journal
Dans: Antiviral Research, vol. 154, p. 116–123, 2018, ISSN: 1872-9096.
Résumé | Liens | BibTeX | Étiquettes: Animals, Antiviral Agents, Cell Line, Cell Membrane, Chemistry, Chlorocebus aethiops, Dendritic Cells, Dengue, Dengue virus, development, Drug, Drug Discovery, Flavivirus, function, Fusion, Glycolipids, Health, Hep G2 Cells, Human, Humans, immunopathology, infection, inhibition, inhibitors, Inhibitory Concentration 50, lipid, Macrophages, Mannosides, Membrane, Serogroup, Skin, Team-Mueller, vaccine, Vaccines, Vero Cells, viral Infection, virus, Virus Replication
@article{schaeffer_inhibition_2018b,
title = {Inhibition of dengue virus infection by mannoside glycolipid conjugates},
author = {Evelyne Schaeffer and Vincent Flacher and Patrick Neuberg and Astrid Hoste and Adrien Brulefert and Jean-Daniel Fauny and Alain Wagner and Christopher G Mueller},
doi = {10.1016/j.antiviral.2018.04.005},
issn = {1872-9096},
year = {2018},
date = {2018-01-01},
journal = {Antiviral Research},
volume = {154},
pages = {116--123},
abstract = {Dengue virus (DENV), a mosquito-borne flavivirus, causes severe and potentially fatal symptoms in millions of infected individuals each year. Although dengue fever represents a major global public health problem, the vaccines or antiviral drugs proposed so far have not shown sufficient efficacy and safety, calling for new antiviral developments. Here we have shown that a mannoside glycolipid conjugate (MGC) bearing a trimannose head with a saturated lipid chain inhibited DENV productive infection. It showed remarkable cell promiscuity, being active in human skin dendritic cells, hepatoma cell lines and Vero cells, and was active against all four DENV serotypes, with an IC50 in the low micromolar range. Time-of-addition experiments and structure-activity analyses revealed the importance of the lipid chain to interfere with an early viral infection step. This, together with a correlation between antiviral activity and membrane polarization by the lipid moiety indicated that the inhibitor functions by blocking viral envelope fusion with the endosome membrane. These finding establish MGCs as a novel class of antivirals against the DENV.},
keywords = {Animals, Antiviral Agents, Cell Line, Cell Membrane, Chemistry, Chlorocebus aethiops, Dendritic Cells, Dengue, Dengue virus, development, Drug, Drug Discovery, Flavivirus, function, Fusion, Glycolipids, Health, Hep G2 Cells, Human, Humans, immunopathology, infection, inhibition, inhibitors, Inhibitory Concentration 50, lipid, Macrophages, Mannosides, Membrane, Serogroup, Skin, Team-Mueller, vaccine, Vaccines, Vero Cells, viral Infection, virus, Virus Replication},
pubstate = {published},
tppubtype = {article}
}
Dengue virus (DENV), a mosquito-borne flavivirus, causes severe and potentially fatal symptoms in millions of infected individuals each year. Although dengue fever represents a major global public health problem, the vaccines or antiviral drugs proposed so far have not shown sufficient efficacy and safety, calling for new antiviral developments. Here we have shown that a mannoside glycolipid conjugate (MGC) bearing a trimannose head with a saturated lipid chain inhibited DENV productive infection. It showed remarkable cell promiscuity, being active in human skin dendritic cells, hepatoma cell lines and Vero cells, and was active against all four DENV serotypes, with an IC50 in the low micromolar range. Time-of-addition experiments and structure-activity analyses revealed the importance of the lipid chain to interfere with an early viral infection step. This, together with a correlation between antiviral activity and membrane polarization by the lipid moiety indicated that the inhibitor functions by blocking viral envelope fusion with the endosome membrane. These finding establish MGCs as a novel class of antivirals against the DENV.
2017
Gies Vincent, Wagner Alain, Seifert Cécile, Guffroy Aurélien, Fauny Jean-D., Knapp Anne-M., Pasquali Jean-L., Martin Thierry, Dumortier Hélène, Korganow Anne-S., Soulas-Sprauel Pauline
Identification of autoreactive B cells with labeled nucleosomes Article de journal
Dans: Scientific Reports, vol. 7, no. 1, p. 602, 2017, ISSN: 2045-2322.
Résumé | Liens | BibTeX | Étiquettes: Animals, Autoantibodies, Autoantigens, Autoimmunity, B-Lymphocytes, Biomarkers, Cell Line, Dumortier, Female, Flow Cytometry, Humans, I2CT, Lupus Erythematosus, Mice, Nucleosomes, Staining and Labeling, Systemic, Team-Dumortier
@article{gies_identification_2017b,
title = {Identification of autoreactive B cells with labeled nucleosomes},
author = {Vincent Gies and Alain Wagner and Cécile Seifert and Aurélien Guffroy and Jean-D. Fauny and Anne-M. Knapp and Jean-L. Pasquali and Thierry Martin and Hélène Dumortier and Anne-S. Korganow and Pauline Soulas-Sprauel},
doi = {10.1038/s41598-017-00664-0},
issn = {2045-2322},
year = {2017},
date = {2017-01-01},
journal = {Scientific Reports},
volume = {7},
number = {1},
pages = {602},
abstract = {The pathogenesis of autoimmune diseases has not been completely elucidated yet, and only a few specific treatments have been developed so far. In autoimmune diseases mediated by pathogenic autoantibodies, such as systemic lupus erythematosus, the specific detection and analysis of autoreactive B cells is crucial for a better understanding of the physiopathology. Biological characterization of these cells may help to define new therapeutic targets. Very few techniques allowing the precise detection of autoreactive B cells have been described so far. Herein we propose a new flow cytometry technique for specific detection of anti-nucleosome B cells, which secrete autoantibodies in systemic lupus erythematosus, using labeled nucleosomes. We produced different fluorochrome-labeled nucleosomes, characterized them, and finally tested them in flow cytometry. Nucleosomes labeled via the cysteines present in H3 histone specifically bind to autoreactive B cells in the anti-DNA transgenic B6.56R mice model. The present work validates the use of fluorochrome-labeled nucleosomes via cysteines to identify anti-nucleosome B cells and offers new opportunities for the description of autoreactive B cell phenotype.},
keywords = {Animals, Autoantibodies, Autoantigens, Autoimmunity, B-Lymphocytes, Biomarkers, Cell Line, Dumortier, Female, Flow Cytometry, Humans, I2CT, Lupus Erythematosus, Mice, Nucleosomes, Staining and Labeling, Systemic, Team-Dumortier},
pubstate = {published},
tppubtype = {article}
}
The pathogenesis of autoimmune diseases has not been completely elucidated yet, and only a few specific treatments have been developed so far. In autoimmune diseases mediated by pathogenic autoantibodies, such as systemic lupus erythematosus, the specific detection and analysis of autoreactive B cells is crucial for a better understanding of the physiopathology. Biological characterization of these cells may help to define new therapeutic targets. Very few techniques allowing the precise detection of autoreactive B cells have been described so far. Herein we propose a new flow cytometry technique for specific detection of anti-nucleosome B cells, which secrete autoantibodies in systemic lupus erythematosus, using labeled nucleosomes. We produced different fluorochrome-labeled nucleosomes, characterized them, and finally tested them in flow cytometry. Nucleosomes labeled via the cysteines present in H3 histone specifically bind to autoreactive B cells in the anti-DNA transgenic B6.56R mice model. The present work validates the use of fluorochrome-labeled nucleosomes via cysteines to identify anti-nucleosome B cells and offers new opportunities for the description of autoreactive B cell phenotype.
2014
Goto Akira, Fukuyama Hidehiro, Imler Jean-Luc, Hoffmann Jules A
The chromatin regulator DMAP1 modulates activity of the nuclear factor B (NF-B) transcription factor Relish in the Drosophila innate immune response Article de journal
Dans: The Journal of Biological Chemistry, vol. 289, no. 30, p. 20470–20476, 2014, ISSN: 1083-351X.
Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Line, Chromatin Assembly and Disassembly, Epistasis, Escherichia coli, Escherichia coli Infections, Genetic, hoffmann, imler, Immunity, Innate, M3i, NF-kappa B, Repressor Proteins, Signal Transduction, Transcription Factors
@article{goto_chromatin_2014,
title = {The chromatin regulator DMAP1 modulates activity of the nuclear factor B (NF-B) transcription factor Relish in the Drosophila innate immune response},
author = {Akira Goto and Hidehiro Fukuyama and Jean-Luc Imler and Jules A Hoffmann},
doi = {10.1074/jbc.C114.553719},
issn = {1083-351X},
year = {2014},
date = {2014-07-01},
journal = {The Journal of Biological Chemistry},
volume = {289},
number = {30},
pages = {20470--20476},
abstract = {The host defense of the model organism Drosophila is under the control of two major signaling cascades controlling transcription factors of the NF-B family, the Toll and the immune deficiency (IMD) pathways. The latter shares extensive similarities with the mammalian TNF-R pathway and was initially discovered for its role in anti-Gram-negative bacterial reactions. A previous interactome study from this laboratory reported that an unexpectedly large number of proteins are binding to the canonical components of the IMD pathway. Here, we focus on DNA methyltransferase-associated protein 1 (DMAP1), which this study identified as an interactant of Relish, a Drosophila transcription factor reminiscent of the mammalian p105 NF-B protein. We show that silencing of DMAP1 expression both in S2 cells and in flies results in a significant reduction of Escherichia coli-induced expression of antimicrobial peptides. Epistatic analysis indicates that DMAP1 acts in parallel or downstream of Relish. Co-immunoprecipitation experiments further reveal that, in addition to Relish, DMAP1 also interacts with Akirin and the Brahma-associated protein 55 kDa (BAP55). Taken together, these results reveal that DMAP1 is a novel nuclear modulator of the IMD pathway, possibly acting at the level of chromatin remodeling.},
keywords = {Animals, Cell Line, Chromatin Assembly and Disassembly, Epistasis, Escherichia coli, Escherichia coli Infections, Genetic, hoffmann, imler, Immunity, Innate, M3i, NF-kappa B, Repressor Proteins, Signal Transduction, Transcription Factors},
pubstate = {published},
tppubtype = {article}
}
The host defense of the model organism Drosophila is under the control of two major signaling cascades controlling transcription factors of the NF-B family, the Toll and the immune deficiency (IMD) pathways. The latter shares extensive similarities with the mammalian TNF-R pathway and was initially discovered for its role in anti-Gram-negative bacterial reactions. A previous interactome study from this laboratory reported that an unexpectedly large number of proteins are binding to the canonical components of the IMD pathway. Here, we focus on DNA methyltransferase-associated protein 1 (DMAP1), which this study identified as an interactant of Relish, a Drosophila transcription factor reminiscent of the mammalian p105 NF-B protein. We show that silencing of DMAP1 expression both in S2 cells and in flies results in a significant reduction of Escherichia coli-induced expression of antimicrobial peptides. Epistatic analysis indicates that DMAP1 acts in parallel or downstream of Relish. Co-immunoprecipitation experiments further reveal that, in addition to Relish, DMAP1 also interacts with Akirin and the Brahma-associated protein 55 kDa (BAP55). Taken together, these results reveal that DMAP1 is a novel nuclear modulator of the IMD pathway, possibly acting at the level of chromatin remodeling.
2013
Petrillo Jessica E, Venter Arno P, Short James R, Gopal Radhika, Deddouche Safia, Lamiable Olivier, Imler Jean-Luc, Schneemann Anette
Cytoplasmic granule formation and translational inhibition of nodaviral RNAs in the absence of the double-stranded RNA binding protein B2 Article de journal
Dans: Journal of Virology, vol. 87, no. 24, p. 13409–13421, 2013, ISSN: 1098-5514.
Résumé | Liens | BibTeX | Étiquettes: Animals, Capsid Proteins, Cell Line, Cricetinae, Cytoplasmic Granules, Double-Stranded, imler, M3i, Nodaviridae, Protein Biosynthesis, RNA, RNA Virus Infections, RNA-Binding Proteins, Viral, Viral Proteins
@article{petrillo_cytoplasmic_2013,
title = {Cytoplasmic granule formation and translational inhibition of nodaviral RNAs in the absence of the double-stranded RNA binding protein B2},
author = {Jessica E Petrillo and Arno P Venter and James R Short and Radhika Gopal and Safia Deddouche and Olivier Lamiable and Jean-Luc Imler and Anette Schneemann},
doi = {10.1128/JVI.02362-13},
issn = {1098-5514},
year = {2013},
date = {2013-12-01},
journal = {Journal of Virology},
volume = {87},
number = {24},
pages = {13409--13421},
abstract = {Flock House virus (FHV) is a positive-sense RNA insect virus with a bipartite genome. RNA1 encodes the RNA-dependent RNA polymerase, and RNA2 encodes the capsid protein. A third protein, B2, is translated from a subgenomic RNA3 derived from the 3' end of RNA1. B2 is a double-stranded RNA (dsRNA) binding protein that inhibits RNA silencing, a major antiviral defense pathway in insects. FHV is conveniently propagated in Drosophila melanogaster cells but can also be grown in mammalian cells. It was previously reported that B2 is dispensable for FHV RNA replication in BHK21 cells; therefore, we chose this cell line to generate a viral mutant that lacked the ability to produce B2. Consistent with published results, we found that RNA replication was indeed vigorous but the yield of progeny virus was negligible. Closer inspection revealed that infected cells contained very small amounts of coat protein despite an abundance of RNA2. B2 mutants that had reduced affinity for dsRNA produced analogous results, suggesting that the dsRNA binding capacity of B2 somehow played a role in coat protein synthesis. Using fluorescence in situ hybridization of FHV RNAs, we discovered that RNA2 is recruited into large cytoplasmic granules in the absence of B2, whereas the distribution of RNA1 remains largely unaffected. We conclude that B2, by binding to double-stranded regions in progeny RNA2, prevents recruitment of RNA2 into cellular structures, where it is translationally silenced. This represents a novel function of B2 that further contributes to successful completion of the nodaviral life cycle.},
keywords = {Animals, Capsid Proteins, Cell Line, Cricetinae, Cytoplasmic Granules, Double-Stranded, imler, M3i, Nodaviridae, Protein Biosynthesis, RNA, RNA Virus Infections, RNA-Binding Proteins, Viral, Viral Proteins},
pubstate = {published},
tppubtype = {article}
}
Flock House virus (FHV) is a positive-sense RNA insect virus with a bipartite genome. RNA1 encodes the RNA-dependent RNA polymerase, and RNA2 encodes the capsid protein. A third protein, B2, is translated from a subgenomic RNA3 derived from the 3' end of RNA1. B2 is a double-stranded RNA (dsRNA) binding protein that inhibits RNA silencing, a major antiviral defense pathway in insects. FHV is conveniently propagated in Drosophila melanogaster cells but can also be grown in mammalian cells. It was previously reported that B2 is dispensable for FHV RNA replication in BHK21 cells; therefore, we chose this cell line to generate a viral mutant that lacked the ability to produce B2. Consistent with published results, we found that RNA replication was indeed vigorous but the yield of progeny virus was negligible. Closer inspection revealed that infected cells contained very small amounts of coat protein despite an abundance of RNA2. B2 mutants that had reduced affinity for dsRNA produced analogous results, suggesting that the dsRNA binding capacity of B2 somehow played a role in coat protein synthesis. Using fluorescence in situ hybridization of FHV RNAs, we discovered that RNA2 is recruited into large cytoplasmic granules in the absence of B2, whereas the distribution of RNA1 remains largely unaffected. We conclude that B2, by binding to double-stranded regions in progeny RNA2, prevents recruitment of RNA2 into cellular structures, where it is translationally silenced. This represents a novel function of B2 that further contributes to successful completion of the nodaviral life cycle.
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.
2012
Thomann Jean-Sébastien, Monneaux Fanny, Creusat Gaëlle, Spanedda Maria Vittoria, Heurtault Béatrice, Habermacher Chloé, Schuber Francis, Bourel-Bonnet Line, Frisch Benoît
Novel glycolipid TLR2 ligands of the type Pam2Cys-α-Gal: synthesis and biological properties Article de journal
Dans: European Journal of Medicinal Chemistry, vol. 51, p. 174–183, 2012, ISSN: 1768-3254.
Résumé | Liens | BibTeX | Étiquettes: Adjuvants, Animals, Cell Line, Chemistry Techniques, Female, Galactose, Glycolipids, Humans, I2CT, Immunologic, ligands, Mice, Monneaux, Structure-Activity Relationship, Synthetic, Team-Dumortier, Toll-Like Receptor 2
@article{thomann_novel_2012,
title = {Novel glycolipid TLR2 ligands of the type Pam2Cys-α-Gal: synthesis and biological properties},
author = {Jean-Sébastien Thomann and Fanny Monneaux and Gaëlle Creusat and Maria Vittoria Spanedda and Béatrice Heurtault and Chloé Habermacher and Francis Schuber and Line Bourel-Bonnet and Benoît Frisch},
doi = {10.1016/j.ejmech.2012.02.039},
issn = {1768-3254},
year = {2012},
date = {2012-05-01},
journal = {European Journal of Medicinal Chemistry},
volume = {51},
pages = {174--183},
abstract = {A more complete understanding of the mechanism of action of TLR agonists has fueled the investigation of new synthetic immunoadjuvants. In this context, we designed and synthesized glycolipids of the type Pam(2)Cys-α-Galactose as novel immunoadjuvants. Their synthesis required modifying a hydrophobic tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety, i.e. the minimal structure required for TLR2 agonist activity, by addition of a hydrophilic head, either an α-Galactosylpyranose or an α-Galactosylfuranose to gain respectively Pam(2)CGalp and Pam(2)CGalf. While preparing a carbohydrate building block, an unexpected stereoselectivity was observed during a halide ion-catalytic process on a protected galactofuranose: the alpha anomer was obtained with surprisingly high selectivity (α/β ratiotextgreater9) and with good isolated yield (51%). The TLR2 binding properties of Pam(2)CGalp and Pam(2)CGalf were then fully evaluated. Their efficiency in triggering the proliferation of BALB/c mouse splenocytes was also compared to that of Pam(2)CAG and Pam(3)CAG, two well-established ligands of TLRs. Moreover, the maturation state of murine dendritic cells previously incubated with either Pam(2)CGalp or Pam(2)CGalf was monitored by flow cytometry and compared to that induced by lipopolysaccharide. Pam(2)CGalp and Pam(2)CGalf were found to be equivalent TLR2 agonists, and induced splenocyte proliferation and DC maturation. With very similar activity, Pam(2)CGalp and Pam(2)CGalf were also 10-fold to 100-fold better than Pam(2)CAG and Pam(3)CAG at inducing B cell proliferation. This represents the first time a glucidic head has been added to the tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety whilst maintaining the immunomodulating activity. This should greatly enrich the data available on Pam(2)C structure/activity relationships.},
keywords = {Adjuvants, Animals, Cell Line, Chemistry Techniques, Female, Galactose, Glycolipids, Humans, I2CT, Immunologic, ligands, Mice, Monneaux, Structure-Activity Relationship, Synthetic, Team-Dumortier, Toll-Like Receptor 2},
pubstate = {published},
tppubtype = {article}
}
A more complete understanding of the mechanism of action of TLR agonists has fueled the investigation of new synthetic immunoadjuvants. In this context, we designed and synthesized glycolipids of the type Pam(2)Cys-α-Galactose as novel immunoadjuvants. Their synthesis required modifying a hydrophobic tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety, i.e. the minimal structure required for TLR2 agonist activity, by addition of a hydrophilic head, either an α-Galactosylpyranose or an α-Galactosylfuranose to gain respectively Pam(2)CGalp and Pam(2)CGalf. While preparing a carbohydrate building block, an unexpected stereoselectivity was observed during a halide ion-catalytic process on a protected galactofuranose: the alpha anomer was obtained with surprisingly high selectivity (α/β ratiotextgreater9) and with good isolated yield (51%). The TLR2 binding properties of Pam(2)CGalp and Pam(2)CGalf were then fully evaluated. Their efficiency in triggering the proliferation of BALB/c mouse splenocytes was also compared to that of Pam(2)CAG and Pam(3)CAG, two well-established ligands of TLRs. Moreover, the maturation state of murine dendritic cells previously incubated with either Pam(2)CGalp or Pam(2)CGalf was monitored by flow cytometry and compared to that induced by lipopolysaccharide. Pam(2)CGalp and Pam(2)CGalf were found to be equivalent TLR2 agonists, and induced splenocyte proliferation and DC maturation. With very similar activity, Pam(2)CGalp and Pam(2)CGalf were also 10-fold to 100-fold better than Pam(2)CAG and Pam(3)CAG at inducing B cell proliferation. This represents the first time a glucidic head has been added to the tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety whilst maintaining the immunomodulating activity. This should greatly enrich the data available on Pam(2)C structure/activity relationships.
Lamanna Giuseppe, Russier Julie, Dumortier Hélène, Bianco Alberto
Enhancement of anti-inflammatory drug activity by multivalent adamantane-based dendrons Article de journal
Dans: Biomaterials, vol. 33, no. 22, p. 5610–5617, 2012, ISSN: 1878-5905.
Résumé | Liens | BibTeX | Étiquettes: Animals, Anti-Inflammatory Agents, Cell Line, Cell Survival, Dendrimers, Drug Synergism, Dumortier, I2CT, Ibuprofen, Macrophages, Mice, Team-Bianco, Team-Dumortier
@article{lamanna_enhancement_2012,
title = {Enhancement of anti-inflammatory drug activity by multivalent adamantane-based dendrons},
author = {Giuseppe Lamanna and Julie Russier and Hélène Dumortier and Alberto Bianco},
doi = {10.1016/j.biomaterials.2012.03.072},
issn = {1878-5905},
year = {2012},
date = {2012-01-01},
journal = {Biomaterials},
volume = {33},
number = {22},
pages = {5610--5617},
abstract = {We have developed a straightforward method to prepare 1(st) and 2(nd) generation adamantane-based dendrons, previously called HYDRAmers, bearing at the periphery the anti-inflammatory drug, ibuprofen. The multivalency effect on the drug activity was studied, demonstrating that our multivalent ibuprofen-dendron conjugates exert an enhanced anti-inflammatory activity compared to free ibuprofen, in vitro. These results provide insights into the effect of HYDRAmer multivalency on biological interactions for therapeutic applications.},
keywords = {Animals, Anti-Inflammatory Agents, Cell Line, Cell Survival, Dendrimers, Drug Synergism, Dumortier, I2CT, Ibuprofen, Macrophages, Mice, Team-Bianco, Team-Dumortier},
pubstate = {published},
tppubtype = {article}
}
We have developed a straightforward method to prepare 1(st) and 2(nd) generation adamantane-based dendrons, previously called HYDRAmers, bearing at the periphery the anti-inflammatory drug, ibuprofen. The multivalency effect on the drug activity was studied, demonstrating that our multivalent ibuprofen-dendron conjugates exert an enhanced anti-inflammatory activity compared to free ibuprofen, in vitro. These results provide insights into the effect of HYDRAmer multivalency on biological interactions for therapeutic applications.
Lacerda Lara, Russier Julie, Pastorin Giorgia, Herrero Antonia M, Venturelli Enrica, Dumortier Hélène, Al-Jamal Khuloud T, Prato Maurizio, Kostarelos Kostas, Bianco Alberto
Translocation mechanisms of chemically functionalised carbon nanotubes across plasma membranes Article de journal
Dans: Biomaterials, vol. 33, no. 11, p. 3334–3343, 2012, ISSN: 1878-5905.
Résumé | Liens | BibTeX | Étiquettes: Animals, carbon, Cell Line, Cell Membrane, Dumortier, I2CT, Macrophages, Mice, Nanotubes, Phagocytosis, Team-Bianco, Team-Dumortier
@article{lacerda_translocation_2012,
title = {Translocation mechanisms of chemically functionalised carbon nanotubes across plasma membranes},
author = {Lara Lacerda and Julie Russier and Giorgia Pastorin and Antonia M Herrero and Enrica Venturelli and Hélène Dumortier and Khuloud T Al-Jamal and Maurizio Prato and Kostas Kostarelos and Alberto Bianco},
doi = {10.1016/j.biomaterials.2012.01.024},
issn = {1878-5905},
year = {2012},
date = {2012-01-01},
journal = {Biomaterials},
volume = {33},
number = {11},
pages = {3334--3343},
abstract = {Understanding the mechanisms responsible for carbon nanotube (CNT) internalisation into live cells is considered critical both from a fundamental point of view and for further engineering of CNT-based delivery systems to intracellular targets. While several studies are focused on the development of such CNT-based delivery systems, attempts to systematically elucidate the cellular uptake mechanisms of CNTs are still rather limited. The aim of the present study is to evaluate the cellular internalisation of chemically functionalised multi-walled carbon nanotubes (f-MWCNTs) in the presence of different well-known cellular uptake inhibitors. Our data reveal how f-MWCNTs are able to translocate across cell membranes of both phagocytic and non-phagocytic cell lines. We have evidenced that at least 30-50% of f-MWCNTs are taken up by cells through an energy-independent mechanism. This characteristic makes nanotubes loaded with therapeutic or diagnostic cargos extremely interesting as the release of active molecules directly into the cytoplasm increase their biological activity and therapeutic efficacy.},
keywords = {Animals, carbon, Cell Line, Cell Membrane, Dumortier, I2CT, Macrophages, Mice, Nanotubes, Phagocytosis, Team-Bianco, Team-Dumortier},
pubstate = {published},
tppubtype = {article}
}
Understanding the mechanisms responsible for carbon nanotube (CNT) internalisation into live cells is considered critical both from a fundamental point of view and for further engineering of CNT-based delivery systems to intracellular targets. While several studies are focused on the development of such CNT-based delivery systems, attempts to systematically elucidate the cellular uptake mechanisms of CNTs are still rather limited. The aim of the present study is to evaluate the cellular internalisation of chemically functionalised multi-walled carbon nanotubes (f-MWCNTs) in the presence of different well-known cellular uptake inhibitors. Our data reveal how f-MWCNTs are able to translocate across cell membranes of both phagocytic and non-phagocytic cell lines. We have evidenced that at least 30-50% of f-MWCNTs are taken up by cells through an energy-independent mechanism. This characteristic makes nanotubes loaded with therapeutic or diagnostic cargos extremely interesting as the release of active molecules directly into the cytoplasm increase their biological activity and therapeutic efficacy.
2011
Ali-Boucetta Hanene, Al-Jamal Khuloud T, Müller Karin H, Li Shouping, Porter Alexandra E, Eddaoudi Ayad, Prato Maurizio, Bianco Alberto, Kostarelos Kostas
Cellular uptake and cytotoxic impact of chemically functionalized and polymer-coated carbon nanotubes Article de journal
Dans: Small (Weinheim an Der Bergstrasse, Germany), vol. 7, no. 22, p. 3230–3238, 2011, ISSN: 1613-6829.
Résumé | Liens | BibTeX | Étiquettes: Annexin A5, carbon, Cell Death, Cell Line, Endocytosis, Flow Cytometry, Fluorescein-5-isothiocyanate, Humans, I2CT, L-Lactate Dehydrogenase, mitochondria, Nanotubes, Polymers, Propidium, Surface Properties, Team-Bianco, tumor, water
@article{ali-boucetta_cellular_2011,
title = {Cellular uptake and cytotoxic impact of chemically functionalized and polymer-coated carbon nanotubes},
author = {Hanene Ali-Boucetta and Khuloud T Al-Jamal and Karin H Müller and Shouping Li and Alexandra E Porter and Ayad Eddaoudi and Maurizio Prato and Alberto Bianco and Kostas Kostarelos},
doi = {10.1002/smll.201101004},
issn = {1613-6829},
year = {2011},
date = {2011-11-01},
journal = {Small (Weinheim an Der Bergstrasse, Germany)},
volume = {7},
number = {22},
pages = {3230--3238},
abstract = {The impact of nanomaterials such as carbon nanotubes on biological matter is a topic of increasing interest and concern and requires a multifaceted approach to be resolved. A modified cytotoxic (lactate dehydrogenase (LDH)) assay is developed in an attempt to offer a valid and reliable methodology for screening carbon nanotube toxicity in vitro. Two of the most widely used types of surface-modified multiwalled carbon nanotubes (MWNTs) are tested: ammonium-functionalized MWNTs (MWNT-NH3+ ) and Pluronic F127 coated MWNTs (MWNT:F127). Chemically functionalized MWNTs show significantly greater cellular uptake into lung epithelial A549 cells compared to the non-covalently Pluronic F127-coated MWNTs. In spite of this, MWNT:F127 exhibit enhanced cytotoxicity according to the modified LDH assay. The validity of the modified LDH assay is further validated by direct comparison with other less reliable or accurate cytotoxicity assays. These findings indicate the reliability of the modified LDH assay as a screening tool to assess carbon nanotube cytotoxicity and illustrate that high levels of carbon nanotube cellular internalization do not necessarily lead to adverse responses.},
keywords = {Annexin A5, carbon, Cell Death, Cell Line, Endocytosis, Flow Cytometry, Fluorescein-5-isothiocyanate, Humans, I2CT, L-Lactate Dehydrogenase, mitochondria, Nanotubes, Polymers, Propidium, Surface Properties, Team-Bianco, tumor, water},
pubstate = {published},
tppubtype = {article}
}
The impact of nanomaterials such as carbon nanotubes on biological matter is a topic of increasing interest and concern and requires a multifaceted approach to be resolved. A modified cytotoxic (lactate dehydrogenase (LDH)) assay is developed in an attempt to offer a valid and reliable methodology for screening carbon nanotube toxicity in vitro. Two of the most widely used types of surface-modified multiwalled carbon nanotubes (MWNTs) are tested: ammonium-functionalized MWNTs (MWNT-NH3+ ) and Pluronic F127 coated MWNTs (MWNT:F127). Chemically functionalized MWNTs show significantly greater cellular uptake into lung epithelial A549 cells compared to the non-covalently Pluronic F127-coated MWNTs. In spite of this, MWNT:F127 exhibit enhanced cytotoxicity according to the modified LDH assay. The validity of the modified LDH assay is further validated by direct comparison with other less reliable or accurate cytotoxicity assays. These findings indicate the reliability of the modified LDH assay as a screening tool to assess carbon nanotube cytotoxicity and illustrate that high levels of carbon nanotube cellular internalization do not necessarily lead to adverse responses.
Lamanna Giuseppe, Russier Julie, Ménard-Moyon Cécilia, Bianco Alberto
HYDRAmers: design, synthesis and characterization of different generation novel Hydra-like dendrons based on multifunctionalized adamantane Article de journal
Dans: Chemical Communications (Cambridge, England), vol. 47, no. 31, p. 8955–8957, 2011, ISSN: 1364-548X.
Résumé | Liens | BibTeX | Étiquettes: Adamantane, Animals, Cell Line, Dendrimers, Drug Design, Humans, I2CT, L-Lactate Dehydrogenase, Magnetic Resonance Spectroscopy, Mice, Team-Bianco, tumor
@article{lamanna_hydramers_2011,
title = {HYDRAmers: design, synthesis and characterization of different generation novel Hydra-like dendrons based on multifunctionalized adamantane},
author = {Giuseppe Lamanna and Julie Russier and Cécilia Ménard-Moyon and Alberto Bianco},
doi = {10.1039/c1cc11689d},
issn = {1364-548X},
year = {2011},
date = {2011-08-01},
journal = {Chemical Communications (Cambridge, England)},
volume = {47},
number = {31},
pages = {8955--8957},
abstract = {In this communication we present a new synthetic strategy to different generation Hydra-like dendrons based on tetrafunctionalized adamantane as a building block. The novel dendrons, which we termed HYDRAmers, possess at the periphery and at the central core orthogonal protections that can be exploited for conjugation of targeting ligands, drugs and/or imaging probes.},
keywords = {Adamantane, Animals, Cell Line, Dendrimers, Drug Design, Humans, I2CT, L-Lactate Dehydrogenase, Magnetic Resonance Spectroscopy, Mice, Team-Bianco, tumor},
pubstate = {published},
tppubtype = {article}
}
In this communication we present a new synthetic strategy to different generation Hydra-like dendrons based on tetrafunctionalized adamantane as a building block. The novel dendrons, which we termed HYDRAmers, possess at the periphery and at the central core orthogonal protections that can be exploited for conjugation of targeting ligands, drugs and/or imaging probes.
Al-Jamal Khuloud T, Gherardini Lisa, Bardi Giuseppe, Nunes Antonio, Guo Chang, Bussy Cyrill, Herrero Antonia M, Bianco Alberto, Prato Maurizio, Kostarelos Kostas, Pizzorusso Tommaso
Functional motor recovery from brain ischemic insult by carbon nanotube-mediated siRNA silencing Article de journal
Dans: Proceedings of the National Academy of Sciences of the United States of America, vol. 108, no. 27, p. 10952–10957, 2011, ISSN: 1091-6490.
Résumé | Liens | BibTeX | Étiquettes: Animals, Apoptosis, Base Sequence, Brain Ischemia, carbon, Caspase 3, Caspase Inhibitors, Cell Line, Cells, Cultured, Electron, Endothelin-1, Female, Genetic Therapy, I2CT, Inbred C57BL, Mice, Microscopy, Nanomedicine, Nanotubes, Neurons, Psychomotor Performance, Rats, RNA, RNA Interference, Small Interfering, Sprague-Dawley, Team-Bianco, Transmission
@article{al-jamal_functional_2011,
title = {Functional motor recovery from brain ischemic insult by carbon nanotube-mediated siRNA silencing},
author = {Khuloud T Al-Jamal and Lisa Gherardini and Giuseppe Bardi and Antonio Nunes and Chang Guo and Cyrill Bussy and Antonia M Herrero and Alberto Bianco and Maurizio Prato and Kostas Kostarelos and Tommaso Pizzorusso},
doi = {10.1073/pnas.1100930108},
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 = {27},
pages = {10952--10957},
abstract = {Stroke is the second cause of death worldwide with ischemic stroke accounting for 80% of all stroke insults. Caspase-3 activation contributes to brain tissue loss and downstream biochemical events that lead to programmed cell death after traumatic brain injury. Alleviation of symptoms following ischemic neuronal injury can be potentially achieved by either genetic disruption or pharmacological inhibition of caspases. Here, we studied whether silencing of Caspase-3 using carbon nanotube-mediated in vivo RNA interference (RNAi) could offer a therapeutic opportunity against stroke. Effective delivery of siRNA directly to the CNS has been shown to normalize phenotypes in animal models of several neurological diseases. It is shown here that peri-lesional stereotactic administration of a Caspase-3 siRNA (siCas 3) delivered by functionalized carbon nanotubes (f-CNT) reduced neurodegeneration and promoted functional preservation before and after focal ischemic damage of the rodent motor cortex using an endothelin-1 induced stroke model. These observations illustrate the opportunity offered by carbon nanotube-mediated siRNA delivery and gene silencing of neuronal tissue applicable to a variety of different neuropathological conditions where intervention at well localized brain foci may offer therapeutic and functional benefits.},
keywords = {Animals, Apoptosis, Base Sequence, Brain Ischemia, carbon, Caspase 3, Caspase Inhibitors, Cell Line, Cells, Cultured, Electron, Endothelin-1, Female, Genetic Therapy, I2CT, Inbred C57BL, Mice, Microscopy, Nanomedicine, Nanotubes, Neurons, Psychomotor Performance, Rats, RNA, RNA Interference, Small Interfering, Sprague-Dawley, Team-Bianco, Transmission},
pubstate = {published},
tppubtype = {article}
}
Stroke is the second cause of death worldwide with ischemic stroke accounting for 80% of all stroke insults. Caspase-3 activation contributes to brain tissue loss and downstream biochemical events that lead to programmed cell death after traumatic brain injury. Alleviation of symptoms following ischemic neuronal injury can be potentially achieved by either genetic disruption or pharmacological inhibition of caspases. Here, we studied whether silencing of Caspase-3 using carbon nanotube-mediated in vivo RNA interference (RNAi) could offer a therapeutic opportunity against stroke. Effective delivery of siRNA directly to the CNS has been shown to normalize phenotypes in animal models of several neurological diseases. It is shown here that peri-lesional stereotactic administration of a Caspase-3 siRNA (siCas 3) delivered by functionalized carbon nanotubes (f-CNT) reduced neurodegeneration and promoted functional preservation before and after focal ischemic damage of the rodent motor cortex using an endothelin-1 induced stroke model. These observations illustrate the opportunity offered by carbon nanotube-mediated siRNA delivery and gene silencing of neuronal tissue applicable to a variety of different neuropathological conditions where intervention at well localized brain foci may offer therapeutic and functional benefits.
Al-Jamal Khuloud T, Nerl Hannah, Müller Karin H, Ali-Boucetta Hanene, Li Shouping, Haynes Peter D, Jinschek Joerg R, Prato Maurizio, Bianco Alberto, Kostarelos Kostas, Porter Alexandra E
Cellular uptake mechanisms of functionalised multi-walled carbon nanotubes by 3D electron tomography imaging Article de journal
Dans: Nanoscale, vol. 3, no. 6, p. 2627–2635, 2011, ISSN: 2040-3372.
Résumé | Liens | BibTeX | Étiquettes: carbon, Cell Line, Cell Membrane, Cytoplasm, Electron Microscope Tomography, Humans, I2CT, imaging, Macrophages, Nanotubes, Phagocytosis, Phagosomes, Team-Bianco, Three-Dimensional, tumor
@article{al-jamal_cellular_2011,
title = {Cellular uptake mechanisms of functionalised multi-walled carbon nanotubes by 3D electron tomography imaging},
author = {Khuloud T Al-Jamal and Hannah Nerl and Karin H Müller and Hanene Ali-Boucetta and Shouping Li and Peter D Haynes and Joerg R Jinschek and Maurizio Prato and Alberto Bianco and Kostas Kostarelos and Alexandra E Porter},
doi = {10.1039/c1nr10080g},
issn = {2040-3372},
year = {2011},
date = {2011-06-01},
journal = {Nanoscale},
volume = {3},
number = {6},
pages = {2627--2635},
abstract = {Carbon nanotubes (CNTs) are being investigated for a variety of biomedical applications. Despite numerous studies, the pathways by which carbon nanotubes enter cells and their subsequent intracellular trafficking and distribution remain poorly determined. Here, we use 3-D electron tomography techniques that offer optimum enhancement of contrast between carbon nanotubes and the plasma membrane to investigate the mechanisms involved in the cellular uptake of shortened, functionalised multi-walled carbon nanotubes (MWNT-NH(3)(+)). Both human lung epithelial (A549) cells, that are almost incapable of phagocytosis and primary macrophages, capable of extremely efficient phagocytosis, were used. We observed that MWNT-NH(3)(+) were internalised in both phagocytic and non-phagocytic cells by any one of three mechanisms: (a) individually via membrane wrapping; (b) individually by direct membrane translocation; and (c) in clusters within vesicular compartments. At early time points following intracellular translocation, we noticed accumulation of nanotube material within various intracellular compartments, while a long-term (14-day) study using primary human macrophages revealed that MWNT-NH(3)(+) were able to escape vesicular (phagosome) entrapment by translocating directly into the cytoplasm.},
keywords = {carbon, Cell Line, Cell Membrane, Cytoplasm, Electron Microscope Tomography, Humans, I2CT, imaging, Macrophages, Nanotubes, Phagocytosis, Phagosomes, Team-Bianco, Three-Dimensional, tumor},
pubstate = {published},
tppubtype = {article}
}
Carbon nanotubes (CNTs) are being investigated for a variety of biomedical applications. Despite numerous studies, the pathways by which carbon nanotubes enter cells and their subsequent intracellular trafficking and distribution remain poorly determined. Here, we use 3-D electron tomography techniques that offer optimum enhancement of contrast between carbon nanotubes and the plasma membrane to investigate the mechanisms involved in the cellular uptake of shortened, functionalised multi-walled carbon nanotubes (MWNT-NH(3)(+)). Both human lung epithelial (A549) cells, that are almost incapable of phagocytosis and primary macrophages, capable of extremely efficient phagocytosis, were used. We observed that MWNT-NH(3)(+) were internalised in both phagocytic and non-phagocytic cells by any one of three mechanisms: (a) individually via membrane wrapping; (b) individually by direct membrane translocation; and (c) in clusters within vesicular compartments. At early time points following intracellular translocation, we noticed accumulation of nanotube material within various intracellular compartments, while a long-term (14-day) study using primary human macrophages revealed that MWNT-NH(3)(+) were able to escape vesicular (phagosome) entrapment by translocating directly into the cytoplasm.
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.
2010
Cellot Giada, Ballerini Laura, Prato Maurizio, Bianco Alberto
Neurons are able to internalize soluble carbon nanotubes: new opportunities or old risks? Article de journal
Dans: Small (Weinheim an Der Bergstrasse, Germany), vol. 6, no. 23, p. 2630–2633, 2010, ISSN: 1613-6829.
Liens | BibTeX | Étiquettes: carbon, Cell Line, Cells, Cultured, Humans, I2CT, Nanotubes, Neurons, Team-Bianco, tumor
@article{cellot_neurons_2010,
title = {Neurons are able to internalize soluble carbon nanotubes: new opportunities or old risks?},
author = {Giada Cellot and Laura Ballerini and Maurizio Prato and Alberto Bianco},
doi = {10.1002/smll.201000906},
issn = {1613-6829},
year = {2010},
date = {2010-12-01},
journal = {Small (Weinheim an Der Bergstrasse, Germany)},
volume = {6},
number = {23},
pages = {2630--2633},
keywords = {carbon, Cell Line, Cells, Cultured, Humans, I2CT, Nanotubes, Neurons, Team-Bianco, tumor},
pubstate = {published},
tppubtype = {article}
}
Al-Jamal Khuloud T, Toma Francesca M, Yilmazer Açelya, Ali-Boucetta Hanene, Nunes Antonio, Herrero Maria-Antonia, Tian Bowen, Eddaoudi Ayad, Eddaoui Ayad, Al-Jamal Wafa' T, Bianco Alberto, Prato Maurizio, Kostarelo Kostas
Enhanced cellular internalization and gene silencing with a series of cationic dendron-multiwalled carbon nanotube:siRNA complexes Article de journal
Dans: FASEB journal: official publication of the Federation of American Societies for Experimental Biology, vol. 24, no. 11, p. 4354–4365, 2010, ISSN: 1530-6860.
Résumé | Liens | BibTeX | Étiquettes: Biological Transport, carbon, Cations, Cell Line, Cell Survival, Gene Silencing, HeLa Cells, Humans, I2CT, Models, Molecular, Nanotubes, RNA, Small Interfering, Team-Bianco, Transfection, tumor
@article{al-jamal_enhanced_2010,
title = {Enhanced cellular internalization and gene silencing with a series of cationic dendron-multiwalled carbon nanotube:siRNA complexes},
author = {Khuloud T Al-Jamal and Francesca M Toma and Açelya Yilmazer and Hanene Ali-Boucetta and Antonio Nunes and Maria-Antonia Herrero and Bowen Tian and Ayad Eddaoudi and Ayad Eddaoui and Wafa' T Al-Jamal and Alberto Bianco and Maurizio Prato and Kostas Kostarelo},
doi = {10.1096/fj.09-141036},
issn = {1530-6860},
year = {2010},
date = {2010-11-01},
journal = {FASEB journal: official publication of the Federation of American Societies for Experimental Biology},
volume = {24},
number = {11},
pages = {4354--4365},
abstract = {One of the major obstacles to the clinical development of gene silencing by small interfering RNA (siRNA) is its effective cytoplasmic delivery. Carbon nanotubes have been proposed as novel nanomaterials that can offer significant advantages for the intracellular delivery of nucleic acids, such as siRNA. We recently demonstrated in a proof-of-principle study that amino-functionalized multiwalled carbon nanotubes (f-MWNT) can effectively deliver in vivo an siRNA sequence, triggering cell apoptosis that results in human lung xenograft eradication and prolonged survival. In the present study, we demonstrate how a newly synthesized series of polycationic dendron-MWNT constructs with a precisely tailored number of amino functions (dendron generations) can complex and effectively deliver double-stranded siRNA to achieve gene silencing in vitro. A systematic comparison between the f-MWNT series in terms of cellular uptake, cytotoxicity, and siRNA complexation is offered. Significant improvement in siRNA delivery with the dendron-MWNT conjugates is shown, and gene silencing was obtained in 2 human cell lines using 2 different siRNA sequences. The study reveals that through f-MWNT structure-biological function analysis novel nanotube-based siRNA transfer vectors can be designed with minimal cytotoxicity and effective delivery and gene-silencing capabilities.},
keywords = {Biological Transport, carbon, Cations, Cell Line, Cell Survival, Gene Silencing, HeLa Cells, Humans, I2CT, Models, Molecular, Nanotubes, RNA, Small Interfering, Team-Bianco, Transfection, tumor},
pubstate = {published},
tppubtype = {article}
}
One of the major obstacles to the clinical development of gene silencing by small interfering RNA (siRNA) is its effective cytoplasmic delivery. Carbon nanotubes have been proposed as novel nanomaterials that can offer significant advantages for the intracellular delivery of nucleic acids, such as siRNA. We recently demonstrated in a proof-of-principle study that amino-functionalized multiwalled carbon nanotubes (f-MWNT) can effectively deliver in vivo an siRNA sequence, triggering cell apoptosis that results in human lung xenograft eradication and prolonged survival. In the present study, we demonstrate how a newly synthesized series of polycationic dendron-MWNT constructs with a precisely tailored number of amino functions (dendron generations) can complex and effectively deliver double-stranded siRNA to achieve gene silencing in vitro. A systematic comparison between the f-MWNT series in terms of cellular uptake, cytotoxicity, and siRNA complexation is offered. Significant improvement in siRNA delivery with the dendron-MWNT conjugates is shown, and gene silencing was obtained in 2 human cell lines using 2 different siRNA sequences. The study reveals that through f-MWNT structure-biological function analysis novel nanotube-based siRNA transfer vectors can be designed with minimal cytotoxicity and effective delivery and gene-silencing capabilities.
den Bossche Jeroen Van, Al-Jamal Wafa' T, Tian Bowen, Nunes Antonio, Fabbro Chiara, Bianco Alberto, Prato Maurizio, Kostarelos Kostas
Efficient receptor-independent intracellular translocation of aptamers mediated by conjugation to carbon nanotubes Article de journal
Dans: Chemical Communications (Cambridge, England), vol. 46, no. 39, p. 7379–7381, 2010, ISSN: 1364-548X.
Résumé | Liens | BibTeX | Étiquettes: Aptamers, Base Sequence, Biological Transport, carbon, Cell Line, Cell Surface, DNA Primers, Electron, Electrophoresis, Humans, I2CT, Microscopy, Nanotubes, Nucleotide, Polyacrylamide Gel, Receptors, Team-Bianco, Transmission, tumor
@article{van_den_bossche_efficient_2010,
title = {Efficient receptor-independent intracellular translocation of aptamers mediated by conjugation to carbon nanotubes},
author = {Jeroen Van den Bossche and Wafa' T Al-Jamal and Bowen Tian and Antonio Nunes and Chiara Fabbro and Alberto Bianco and Maurizio Prato and Kostas Kostarelos},
doi = {10.1039/c0cc02092c},
issn = {1364-548X},
year = {2010},
date = {2010-10-01},
journal = {Chemical Communications (Cambridge, England)},
volume = {46},
number = {39},
pages = {7379--7381},
abstract = {We have covalently grafted aptamers onto carboxylated carbon nanotubes to design a novel vector system that can easily translocate into the cytosol of different cell types independent of receptor-mediated uptake. We propose the use of carbon nanotubes for the efficient intracellular delivery of biologically active aptamers for potential therapeutic applications.},
keywords = {Aptamers, Base Sequence, Biological Transport, carbon, Cell Line, Cell Surface, DNA Primers, Electron, Electrophoresis, Humans, I2CT, Microscopy, Nanotubes, Nucleotide, Polyacrylamide Gel, Receptors, Team-Bianco, Transmission, tumor},
pubstate = {published},
tppubtype = {article}
}
We have covalently grafted aptamers onto carboxylated carbon nanotubes to design a novel vector system that can easily translocate into the cytosol of different cell types independent of receptor-mediated uptake. We propose the use of carbon nanotubes for the efficient intracellular delivery of biologically active aptamers for potential therapeutic applications.
Samorì Cristian, Ali-Boucetta Hanene, Sainz Raquel, Guo Chang, Toma Francesca Maria, Fabbro Chiara, da Ros Tatiana, Prato Maurizio, Kostarelos Kostas, Bianco Alberto
Enhanced anticancer activity of multi-walled carbon nanotube-methotrexate conjugates using cleavable linkers Article de journal
Dans: Chemical Communications (Cambridge, England), vol. 46, no. 9, p. 1494–1496, 2010, ISSN: 1364-548X.
Résumé | Liens | BibTeX | Étiquettes: Antineoplastic Agents, Azo Compounds, carbon, Cell Line, Cross-Linking Reagents, Humans, I2CT, Methotrexate, Nanotubes, Team-Bianco, Thiosemicarbazones, tumor
@article{samori_enhanced_2010,
title = {Enhanced anticancer activity of multi-walled carbon nanotube-methotrexate conjugates using cleavable linkers},
author = {Cristian Samorì and Hanene Ali-Boucetta and Raquel Sainz and Chang Guo and Francesca Maria Toma and Chiara Fabbro and Tatiana da Ros and Maurizio Prato and Kostas Kostarelos and Alberto Bianco},
doi = {10.1039/b923560d},
issn = {1364-548X},
year = {2010},
date = {2010-03-01},
journal = {Chemical Communications (Cambridge, England)},
volume = {46},
number = {9},
pages = {1494--1496},
abstract = {Methotrexate was tethered to multi-walled carbon nanotubes through different cleavable linkers exploiting the ammonium functionalities introduced by 1,3-dipolar cycloaddition reaction of azomethine ylides to the nanotubes. The new nanobio-hybrid conjugates were internalized into human breast cancer cells and it was shown that the cytotoxic activity was strongly dependent on the presence and type of linker.},
keywords = {Antineoplastic Agents, Azo Compounds, carbon, Cell Line, Cross-Linking Reagents, Humans, I2CT, Methotrexate, Nanotubes, Team-Bianco, Thiosemicarbazones, tumor},
pubstate = {published},
tppubtype = {article}
}
Methotrexate was tethered to multi-walled carbon nanotubes through different cleavable linkers exploiting the ammonium functionalities introduced by 1,3-dipolar cycloaddition reaction of azomethine ylides to the nanotubes. The new nanobio-hybrid conjugates were internalized into human breast cancer cells and it was shown that the cytotoxic activity was strongly dependent on the presence and type of linker.
2009
Podesta Jennifer E, Al-Jamal Khuloud T, Herrero Antonia M, Tian Bowen, Ali-Boucetta Hanene, Hegde Vikas, Bianco Alberto, Prato Maurizio, Kostarelos Kostas
Antitumor activity and prolonged survival by carbon-nanotube-mediated therapeutic siRNA silencing in a human lung xenograft model Article de journal
Dans: Small (Weinheim an Der Bergstrasse, Germany), vol. 5, no. 10, p. 1176–1185, 2009, ISSN: 1613-6829.
Résumé | Liens | BibTeX | Étiquettes: Animals, Antineoplastic Agents, Apoptosis, carbon, Cell Line, Cell Proliferation, Electrophoresis, Gene Silencing, Humans, I2CT, Liposomes, Lung Neoplasms, Mice, Nanomedicine, Nanotubes, RNA, Small Interfering, Survival Analysis, Team-Bianco, tumor, Xenograft Model Antitumor Assays
@article{podesta_antitumor_2009,
title = {Antitumor activity and prolonged survival by carbon-nanotube-mediated therapeutic siRNA silencing in a human lung xenograft model},
author = {Jennifer E Podesta and Khuloud T Al-Jamal and Antonia M Herrero and Bowen Tian and Hanene Ali-Boucetta and Vikas Hegde and Alberto Bianco and Maurizio Prato and Kostas Kostarelos},
doi = {10.1002/smll.200801572},
issn = {1613-6829},
year = {2009},
date = {2009-05-01},
journal = {Small (Weinheim an Der Bergstrasse, Germany)},
volume = {5},
number = {10},
pages = {1176--1185},
abstract = {Carbon nanotubes are novel nanomaterials that are thought to offer potential benefits to a variety of biomedical and clinical applications. In this study, the treatment of a human lung carcinoma model in vivo using siRNA sequences leading to cytotoxicity and cell death is carried out using either cationic liposomes (DOTAP:cholesterol) or amino-functionalized multi-walled carbon nanotubes (MWNT - NH(+)(3)). Validation for the most cytotoxic siRNA sequence using a panel of human carcinoma and murine cells reveals that the proprietary siTOX sequence is human specific and can lead to significant cytotoxic activities delivered both by liposome or MWNT - NH(+)(3) in vitro. A comparative study using both types of vector indicates that only MWNT - NH(+)(3):siRNA complexes administered intratumorally can elicit delayed tumor growth and increased survival of xenograft-bearing animals. siTOX delivery via the cationic MWNT - NH(+)(3) is biologically active in vivo by triggering an apoptotic cascade, leading to extensive necrosis of the human tumor mass. This suggests that carbon-nanotube-mediated delivery of siRNA by intratumoral administration leads to successful and statistically significant suppression of tumor volume, followed by a concomitant prolongation of survival of human lung tumor-bearing animals. The direct comparison between carbon nanotubes and liposomes demonstrates the potential advantages offered by carbon nanotubes for the intracellular delivery of therapeutic agents in vivo. The present work may act as the impetus for further studies to explore the therapeutic capacity of chemically functionalized carbon nanotubes to deliver siRNA directly into the cytoplasm of target cells and achieve effective therapeutic silencing in various disease indications where local delivery is feasible or desirable.},
keywords = {Animals, Antineoplastic Agents, Apoptosis, carbon, Cell Line, Cell Proliferation, Electrophoresis, Gene Silencing, Humans, I2CT, Liposomes, Lung Neoplasms, Mice, Nanomedicine, Nanotubes, RNA, Small Interfering, Survival Analysis, Team-Bianco, tumor, Xenograft Model Antitumor Assays},
pubstate = {published},
tppubtype = {article}
}
Carbon nanotubes are novel nanomaterials that are thought to offer potential benefits to a variety of biomedical and clinical applications. In this study, the treatment of a human lung carcinoma model in vivo using siRNA sequences leading to cytotoxicity and cell death is carried out using either cationic liposomes (DOTAP:cholesterol) or amino-functionalized multi-walled carbon nanotubes (MWNT - NH(+)(3)). Validation for the most cytotoxic siRNA sequence using a panel of human carcinoma and murine cells reveals that the proprietary siTOX sequence is human specific and can lead to significant cytotoxic activities delivered both by liposome or MWNT - NH(+)(3) in vitro. A comparative study using both types of vector indicates that only MWNT - NH(+)(3):siRNA complexes administered intratumorally can elicit delayed tumor growth and increased survival of xenograft-bearing animals. siTOX delivery via the cationic MWNT - NH(+)(3) is biologically active in vivo by triggering an apoptotic cascade, leading to extensive necrosis of the human tumor mass. This suggests that carbon-nanotube-mediated delivery of siRNA by intratumoral administration leads to successful and statistically significant suppression of tumor volume, followed by a concomitant prolongation of survival of human lung tumor-bearing animals. The direct comparison between carbon nanotubes and liposomes demonstrates the potential advantages offered by carbon nanotubes for the intracellular delivery of therapeutic agents in vivo. The present work may act as the impetus for further studies to explore the therapeutic capacity of chemically functionalized carbon nanotubes to deliver siRNA directly into the cytoplasm of target cells and achieve effective therapeutic silencing in various disease indications where local delivery is feasible or desirable.
2008
Geotti-Bianchini Piero, Beyrath Julien, Chaloin Olivier, Formaggio Fernando, Bianco Alberto
Design and synthesis of intrinsically cell-penetrating nucleopeptides Article de journal
Dans: Organic & Biomolecular Chemistry, vol. 6, no. 20, p. 3661–3663, 2008, ISSN: 1477-0539.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid Sequence, Cell Line, Cells, Drug Design, Humans, I2CT, Molecular Sequence Data, Peptides, Purines, Pyrimidines, Team-Bianco
@article{geotti-bianchini_design_2008,
title = {Design and synthesis of intrinsically cell-penetrating nucleopeptides},
author = {Piero Geotti-Bianchini and Julien Beyrath and Olivier Chaloin and Fernando Formaggio and Alberto Bianco},
doi = {10.1039/b811639c},
issn = {1477-0539},
year = {2008},
date = {2008-10-01},
journal = {Organic & Biomolecular Chemistry},
volume = {6},
number = {20},
pages = {3661--3663},
abstract = {Nucleopeptides, which are constituted of alpha-amino acids bearing nucleobases at their side chains, are able to penetrate into cells and to reach the nucleus without cytotoxic effects.},
keywords = {Amino Acid Sequence, Cell Line, Cells, Drug Design, Humans, I2CT, Molecular Sequence Data, Peptides, Purines, Pyrimidines, Team-Bianco},
pubstate = {published},
tppubtype = {article}
}
Nucleopeptides, which are constituted of alpha-amino acids bearing nucleobases at their side chains, are able to penetrate into cells and to reach the nucleus without cytotoxic effects.
Kwan Wing-Hong, Navarro-Sanchez Erika, Dumortier Hélène, Decossas Marion, Vachon Hortense, dos Santos Flavia Barreto, Fridman Hervé W, Rey Félix A, Harris Eva, Despres Philippe, Mueller Christopher G
Dermal-type macrophages expressing CD209/DC-SIGN show inherent resistance to dengue virus growth Article de journal
Dans: PLoS neglected tropical diseases, vol. 2, no. 10, p. e311, 2008, ISSN: 1935-2735.
Résumé | Liens | BibTeX | Étiquettes: Adhesion, adhesion molecules, C-Type, Cell Adhesion, Cell Adhesion Molecules, Cell Line, Cell Surface, Cells, Chemistry, Cultured, Dendritic Cells, Dengue, Dengue virus, Gene Expression, Genetics, GLYCOPROTEIN, Growth, growth & development, Humans, ICAM-3, IFN ALPHA, IL-10, IL10, IMMATURE, Immunology, in situ, infection, LECTIN, Lectins, Macrophage, Macrophages, metabolism, METHOD, methods, monocyte, Monocytes, myeloid dendritic cells, pathogenesis, Phagosomes, PRODUCTION, Protein, Protein Binding, Proteins, Receptor, Receptors, Resistance, Skin, Team-Mueller, Viral Envelope Proteins, virology, virus
@article{kwan_dermal-type_2008b,
title = {Dermal-type macrophages expressing CD209/DC-SIGN show inherent resistance to dengue virus growth},
author = {Wing-Hong Kwan and Erika Navarro-Sanchez and Hélène Dumortier and Marion Decossas and Hortense Vachon and Flavia Barreto dos Santos and Hervé W Fridman and Félix A Rey and Eva Harris and Philippe Despres and Christopher G Mueller},
doi = {10.1371/journal.pntd.0000311},
issn = {1935-2735},
year = {2008},
date = {2008-10-01},
journal = {PLoS neglected tropical diseases},
volume = {2},
number = {10},
pages = {e311},
abstract = {BACKGROUND: An important question in dengue pathogenesis is the identity of immune cells involved in the control of dengue virus infection at the site of the mosquito bite. There is evidence that infection of immature myeloid dendritic cells plays a crucial role in dengue pathogenesis and that the interaction of the viral envelope E glycoprotein with CD209/DC-SIGN is a key element for their productive infection. Dermal macrophages express CD209, yet little is known about their role in dengue virus infection.
METHODS AND FINDINGS: Here, we showed that dermal macrophages bound recombinant envelope E glycoprotein fused to green fluorescent protein. Because dermal macrophages stain for IL-10 in situ, we generated dermal-type macrophages from monocytes in the presence of IL-10 to study their infection by dengue virus. The macrophages were able to internalize the virus, but progeny virus production was undetectable in the infected cells. In addition, no IFN-alpha was produced in response to the virus. The inability of dengue virus to grow in the macrophages was attributable to accumulation of internalized virus particles into poorly-acidified phagosomes.
CONCLUSIONS: Aborting infection by viral sequestration in early phagosomes would present a novel means to curb infection of enveloped virus and may constitute a prime defense system to prevent dengue virus spread shortly after the bite of the infected mosquito.},
keywords = {Adhesion, adhesion molecules, C-Type, Cell Adhesion, Cell Adhesion Molecules, Cell Line, Cell Surface, Cells, Chemistry, Cultured, Dendritic Cells, Dengue, Dengue virus, Gene Expression, Genetics, GLYCOPROTEIN, Growth, growth & development, Humans, ICAM-3, IFN ALPHA, IL-10, IL10, IMMATURE, Immunology, in situ, infection, LECTIN, Lectins, Macrophage, Macrophages, metabolism, METHOD, methods, monocyte, Monocytes, myeloid dendritic cells, pathogenesis, Phagosomes, PRODUCTION, Protein, Protein Binding, Proteins, Receptor, Receptors, Resistance, Skin, Team-Mueller, Viral Envelope Proteins, virology, virus},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: An important question in dengue pathogenesis is the identity of immune cells involved in the control of dengue virus infection at the site of the mosquito bite. There is evidence that infection of immature myeloid dendritic cells plays a crucial role in dengue pathogenesis and that the interaction of the viral envelope E glycoprotein with CD209/DC-SIGN is a key element for their productive infection. Dermal macrophages express CD209, yet little is known about their role in dengue virus infection.
METHODS AND FINDINGS: Here, we showed that dermal macrophages bound recombinant envelope E glycoprotein fused to green fluorescent protein. Because dermal macrophages stain for IL-10 in situ, we generated dermal-type macrophages from monocytes in the presence of IL-10 to study their infection by dengue virus. The macrophages were able to internalize the virus, but progeny virus production was undetectable in the infected cells. In addition, no IFN-alpha was produced in response to the virus. The inability of dengue virus to grow in the macrophages was attributable to accumulation of internalized virus particles into poorly-acidified phagosomes.
CONCLUSIONS: Aborting infection by viral sequestration in early phagosomes would present a novel means to curb infection of enveloped virus and may constitute a prime defense system to prevent dengue virus spread shortly after the bite of the infected mosquito.
METHODS AND FINDINGS: Here, we showed that dermal macrophages bound recombinant envelope E glycoprotein fused to green fluorescent protein. Because dermal macrophages stain for IL-10 in situ, we generated dermal-type macrophages from monocytes in the presence of IL-10 to study their infection by dengue virus. The macrophages were able to internalize the virus, but progeny virus production was undetectable in the infected cells. In addition, no IFN-alpha was produced in response to the virus. The inability of dengue virus to grow in the macrophages was attributable to accumulation of internalized virus particles into poorly-acidified phagosomes.
CONCLUSIONS: Aborting infection by viral sequestration in early phagosomes would present a novel means to curb infection of enveloped virus and may constitute a prime defense system to prevent dengue virus spread shortly after the bite of the infected mosquito.
Goto Akira, Matsushita Kazufumi, Gesellchen Viola, Chamy Laure El, Kuttenkeuler David, Takeuchi Osamu, Hoffmann Jules A, Akira Shizuo, Boutros Michael, Reichhart Jean-Marc
Akirins are highly conserved nuclear proteins required for NF-kappaB-dependent gene expression in drosophila and mice Article de journal
Dans: Nat. Immunol., vol. 9, no. 1, p. 97–104, 2008, ISSN: 1529-2916.
Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Line, Embryo, Fibroblasts, hoffmann, Humans, Immunity, Innate, Interleukin-1beta, M3i, Mammalian, Mice, NF-kappa B, Nuclear Proteins, Proteins, reichhart, Signal Transduction, Toll-Like Receptors, transgenic, Tumor Necrosis Factor-alpha
@article{goto_akirins_2008,
title = {Akirins are highly conserved nuclear proteins required for NF-kappaB-dependent gene expression in drosophila and mice},
author = {Akira Goto and Kazufumi Matsushita and Viola Gesellchen and Laure El Chamy and David Kuttenkeuler and Osamu Takeuchi and Jules A Hoffmann and Shizuo Akira and Michael Boutros and Jean-Marc Reichhart},
doi = {10.1038/ni1543},
issn = {1529-2916},
year = {2008},
date = {2008-01-01},
journal = {Nat. Immunol.},
volume = {9},
number = {1},
pages = {97--104},
abstract = {During a genome-wide screen with RNA-mediated interference, we isolated CG8580 as a gene involved in the innate immune response of Drosophila melanogaster. CG8580, which we called Akirin, encoded a protein that acted in parallel with the NF-kappaB transcription factor downstream of the Imd pathway and was required for defense against Gram-negative bacteria. Akirin is highly conserved, and the human genome contains two homologs, one of which was able to rescue the loss-of-function phenotype in drosophila cells. Akirins were strictly localized to the nucleus. Knockout of both Akirin homologs in mice showed that one had an essential function downstream of the Toll-like receptor, tumor necrosis factor and interleukin (IL)-1beta signaling pathways leading to the production of IL-6. Thus, Akirin is a conserved nuclear factor required for innate immune responses.},
keywords = {Animals, Cell Line, Embryo, Fibroblasts, hoffmann, Humans, Immunity, Innate, Interleukin-1beta, M3i, Mammalian, Mice, NF-kappa B, Nuclear Proteins, Proteins, reichhart, Signal Transduction, Toll-Like Receptors, transgenic, Tumor Necrosis Factor-alpha},
pubstate = {published},
tppubtype = {article}
}
During a genome-wide screen with RNA-mediated interference, we isolated CG8580 as a gene involved in the innate immune response of Drosophila melanogaster. CG8580, which we called Akirin, encoded a protein that acted in parallel with the NF-kappaB transcription factor downstream of the Imd pathway and was required for defense against Gram-negative bacteria. Akirin is highly conserved, and the human genome contains two homologs, one of which was able to rescue the loss-of-function phenotype in drosophila cells. Akirins were strictly localized to the nucleus. Knockout of both Akirin homologs in mice showed that one had an essential function downstream of the Toll-like receptor, tumor necrosis factor and interleukin (IL)-1beta signaling pathways leading to the production of IL-6. Thus, Akirin is a conserved nuclear factor required for innate immune responses.
Kwan Wing-Hong, Navarro-Sanchez Erika, Dumortier Hélène, Decossas Marion, Vachon Hortense, dos Santos Flavia Barreto, Fridman Hervé W, Rey Félix A, Harris Eva, Despres Philippe, Mueller Christopher G
Dermal-type macrophages expressing CD209/DC-SIGN show inherent resistance to dengue virus growth Article de journal
Dans: PLoS neglected tropical diseases, vol. 2, no. 10, p. e311, 2008, ISSN: 1935-2735.
Résumé | Liens | BibTeX | Étiquettes: C-Type, Cell Adhesion Molecules, Cell Line, Cell Surface, Cells, Cultured, Dengue, Dengue virus, Dumortier, Gene Expression, Humans, I2CT, Lectins, Macrophages, Protein Binding, Receptors, Skin, Team-Dumortier, Team-Mueller, Viral Envelope Proteins
@article{kwan_dermal-type_2008,
title = {Dermal-type macrophages expressing CD209/DC-SIGN show inherent resistance to dengue virus growth},
author = {Wing-Hong Kwan and Erika Navarro-Sanchez and Hélène Dumortier and Marion Decossas and Hortense Vachon and Flavia Barreto dos Santos and Hervé W Fridman and Félix A Rey and Eva Harris and Philippe Despres and Christopher G Mueller},
doi = {10.1371/journal.pntd.0000311},
issn = {1935-2735},
year = {2008},
date = {2008-01-01},
journal = {PLoS neglected tropical diseases},
volume = {2},
number = {10},
pages = {e311},
abstract = {BACKGROUND: An important question in dengue pathogenesis is the identity of immune cells involved in the control of dengue virus infection at the site of the mosquito bite. There is evidence that infection of immature myeloid dendritic cells plays a crucial role in dengue pathogenesis and that the interaction of the viral envelope E glycoprotein with CD209/DC-SIGN is a key element for their productive infection. Dermal macrophages express CD209, yet little is known about their role in dengue virus infection.
METHODS AND FINDINGS: Here, we showed that dermal macrophages bound recombinant envelope E glycoprotein fused to green fluorescent protein. Because dermal macrophages stain for IL-10 in situ, we generated dermal-type macrophages from monocytes in the presence of IL-10 to study their infection by dengue virus. The macrophages were able to internalize the virus, but progeny virus production was undetectable in the infected cells. In addition, no IFN-alpha was produced in response to the virus. The inability of dengue virus to grow in the macrophages was attributable to accumulation of internalized virus particles into poorly-acidified phagosomes.
CONCLUSIONS: Aborting infection by viral sequestration in early phagosomes would present a novel means to curb infection of enveloped virus and may constitute a prime defense system to prevent dengue virus spread shortly after the bite of the infected mosquito.},
keywords = {C-Type, Cell Adhesion Molecules, Cell Line, Cell Surface, Cells, Cultured, Dengue, Dengue virus, Dumortier, Gene Expression, Humans, I2CT, Lectins, Macrophages, Protein Binding, Receptors, Skin, Team-Dumortier, Team-Mueller, Viral Envelope Proteins},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: An important question in dengue pathogenesis is the identity of immune cells involved in the control of dengue virus infection at the site of the mosquito bite. There is evidence that infection of immature myeloid dendritic cells plays a crucial role in dengue pathogenesis and that the interaction of the viral envelope E glycoprotein with CD209/DC-SIGN is a key element for their productive infection. Dermal macrophages express CD209, yet little is known about their role in dengue virus infection.
METHODS AND FINDINGS: Here, we showed that dermal macrophages bound recombinant envelope E glycoprotein fused to green fluorescent protein. Because dermal macrophages stain for IL-10 in situ, we generated dermal-type macrophages from monocytes in the presence of IL-10 to study their infection by dengue virus. The macrophages were able to internalize the virus, but progeny virus production was undetectable in the infected cells. In addition, no IFN-alpha was produced in response to the virus. The inability of dengue virus to grow in the macrophages was attributable to accumulation of internalized virus particles into poorly-acidified phagosomes.
CONCLUSIONS: Aborting infection by viral sequestration in early phagosomes would present a novel means to curb infection of enveloped virus and may constitute a prime defense system to prevent dengue virus spread shortly after the bite of the infected mosquito.
METHODS AND FINDINGS: Here, we showed that dermal macrophages bound recombinant envelope E glycoprotein fused to green fluorescent protein. Because dermal macrophages stain for IL-10 in situ, we generated dermal-type macrophages from monocytes in the presence of IL-10 to study their infection by dengue virus. The macrophages were able to internalize the virus, but progeny virus production was undetectable in the infected cells. In addition, no IFN-alpha was produced in response to the virus. The inability of dengue virus to grow in the macrophages was attributable to accumulation of internalized virus particles into poorly-acidified phagosomes.
CONCLUSIONS: Aborting infection by viral sequestration in early phagosomes would present a novel means to curb infection of enveloped virus and may constitute a prime defense system to prevent dengue virus spread shortly after the bite of the infected mosquito.
2007
Habib Mohammed, Rivas Magali Noval, Chamekh Mustapha, Wieckowski Sébastien, Sun Weimin, Bianco Alberto, Trouche Nathalie, Chaloin Olivier, Dumortier Hélène, Goldman Michel, Guichard Gilles, Fournel Sylvie, Vray Bernard
Cutting edge: small molecule CD40 ligand mimetics promote control of parasitemia and enhance Ŧ cells producing IFN-gamma during experimental Trypanosoma cruzi infection Article de journal
Dans: Journal of Immunology (Baltimore, Md.: 1950), vol. 178, no. 11, p. 6700–6704, 2007, ISSN: 0022-1767.
Résumé | Liens | BibTeX | Étiquettes: Animals, CD40 Antigens, CD40 Ligand, Cell Line, Cells, Chagas Disease, Cultured, Dumortier, I2CT, Inbred BALB C, Inbred C57BL, Interferon-gamma, Knockout, Mice, Molecular Mimicry, Parasitemia, T-Lymphocyte Subsets, Team-Bianco, Team-Dumortier, Trypanosoma cruzi
@article{habib_cutting_2007,
title = {Cutting edge: small molecule CD40 ligand mimetics promote control of parasitemia and enhance Ŧ cells producing IFN-gamma during experimental Trypanosoma cruzi infection},
author = {Mohammed Habib and Magali Noval Rivas and Mustapha Chamekh and Sébastien Wieckowski and Weimin Sun and Alberto Bianco and Nathalie Trouche and Olivier Chaloin and Hélène Dumortier and Michel Goldman and Gilles Guichard and Sylvie Fournel and Bernard Vray},
doi = {10.4049/jimmunol.178.11.6700},
issn = {0022-1767},
year = {2007},
date = {2007-06-01},
journal = {Journal of Immunology (Baltimore, Md.: 1950)},
volume = {178},
number = {11},
pages = {6700--6704},
abstract = {Host resistance to Trypanosoma cruzi infection depends on a type 1 response characterized by a strong production of IL-12 and IFN-gamma. Amplifying this response through CD40 triggering results in control of parasitemia. Two newly synthesized molecules (textless3 kDa) mimicking trimeric CD40L (mini CD40Ls(-1) and (-2)) bind to CD40, activate murine dendritic cells, and elicit IL-12 production. Wild-type but not CD40 knockout mice exhibited a sharp decrease of parasitemia and mortality when inoculated with T. cruzi mixed with miniCD40Ls. Moreover, the immunosuppression induced by T. cruzi infection was impaired in mice treated with miniCD40Ls, as shown by proliferation of splenic lymphocytes, percentage of CD8(+) T cells, and IFN-gamma production. Mice surviving T. cruzi infection in the presence of miniCD40L(-1) were immunized against a challenge infection. Our results indicate that CD40L mimetics are effective in vivo and promote the control of T. cruzi infection by overcoming the immunosuppression usually induced by the parasites.},
keywords = {Animals, CD40 Antigens, CD40 Ligand, Cell Line, Cells, Chagas Disease, Cultured, Dumortier, I2CT, Inbred BALB C, Inbred C57BL, Interferon-gamma, Knockout, Mice, Molecular Mimicry, Parasitemia, T-Lymphocyte Subsets, Team-Bianco, Team-Dumortier, Trypanosoma cruzi},
pubstate = {published},
tppubtype = {article}
}
Host resistance to Trypanosoma cruzi infection depends on a type 1 response characterized by a strong production of IL-12 and IFN-gamma. Amplifying this response through CD40 triggering results in control of parasitemia. Two newly synthesized molecules (textless3 kDa) mimicking trimeric CD40L (mini CD40Ls(-1) and (-2)) bind to CD40, activate murine dendritic cells, and elicit IL-12 production. Wild-type but not CD40 knockout mice exhibited a sharp decrease of parasitemia and mortality when inoculated with T. cruzi mixed with miniCD40Ls. Moreover, the immunosuppression induced by T. cruzi infection was impaired in mice treated with miniCD40Ls, as shown by proliferation of splenic lymphocytes, percentage of CD8(+) T cells, and IFN-gamma production. Mice surviving T. cruzi infection in the presence of miniCD40L(-1) were immunized against a challenge infection. Our results indicate that CD40L mimetics are effective in vivo and promote the control of T. cruzi infection by overcoming the immunosuppression usually induced by the parasites.
2006
Bianco Alberto, Fournel Sylvie, Wieckowski Sébastien, Hoebeke Johan, Guichard Gilles
Solid-phase synthesis of CD40L mimetics Article de journal
Dans: Organic & Biomolecular Chemistry, vol. 4, no. 8, p. 1461–1463, 2006, ISSN: 1477-0520.
Résumé | Liens | BibTeX | Étiquettes: Apoptosis, CD40 Ligand, Cell Line, Chromatography, Combinatorial Chemistry Techniques, High Pressure Liquid, Humans, I2CT, Molecular Mimicry, Molecular Structure, Protein Binding, Team-Bianco, tumor
@article{bianco_solid-phase_2006,
title = {Solid-phase synthesis of CD40L mimetics},
author = {Alberto Bianco and Sylvie Fournel and Sébastien Wieckowski and Johan Hoebeke and Gilles Guichard},
doi = {10.1039/b601528j},
issn = {1477-0520},
year = {2006},
date = {2006-04-01},
journal = {Organic & Biomolecular Chemistry},
volume = {4},
number = {8},
pages = {1461--1463},
abstract = {The C3-symmetric molecule has been previously shown to mimic CD40 ligand (CD40L) homotrimers and to display effector functions. This molecule consists of a cyclic hexapeptide core containing the repetition of the D-Ala-L-Lys motif. The side chains of the lysine residues have been modified by appending the CD40L-derived sequence 143Lys-Gly-Tyr-Tyr146 via a 6-aminohexanoic acid residue as a spacer. The present report describes a general solid-phase synthesis approach to and related trimeric architectures. In addition, their CD40 binding properties as well as their effector functions have been evaluated.},
keywords = {Apoptosis, CD40 Ligand, Cell Line, Chromatography, Combinatorial Chemistry Techniques, High Pressure Liquid, Humans, I2CT, Molecular Mimicry, Molecular Structure, Protein Binding, Team-Bianco, tumor},
pubstate = {published},
tppubtype = {article}
}
The C3-symmetric molecule has been previously shown to mimic CD40 ligand (CD40L) homotrimers and to display effector functions. This molecule consists of a cyclic hexapeptide core containing the repetition of the D-Ala-L-Lys motif. The side chains of the lysine residues have been modified by appending the CD40L-derived sequence 143Lys-Gly-Tyr-Tyr146 via a 6-aminohexanoic acid residue as a spacer. The present report describes a general solid-phase synthesis approach to and related trimeric architectures. In addition, their CD40 binding properties as well as their effector functions have been evaluated.
2005
Fournel Sylvie, Wieckowski Sébastien, Sun Weimin, Trouche Nathalie, Dumortier Hélène, Bianco Alberto, Chaloin Olivier, Habib Mohammed, Peter Jean-Christophe, Schneider Pascal, Vray Bernard, Toes René E, Offringa Rienk, Melief Cornelis J M, Hoebeke Johan, Guichard Gilles
C3-symmetric peptide scaffolds are functional mimetics of trimeric CD40L Article de journal
Dans: Nature Chemical Biology, vol. 1, no. 7, p. 377–382, 2005, ISSN: 1552-4450.
Résumé | Liens | BibTeX | Étiquettes: Animals, Apoptosis, Biological, CD40 Antigens, CD40 Ligand, Cell Line, Dumortier, Humans, I2CT, Inbred BALB C, Mice, Models, Molecular Mimicry, Molecular Structure, Peptides, Protein Conformation, Protein Structure, Quaternary, Structure-Activity Relationship, Team-Bianco, Team-Dumortier, Time Factors, tumor
@article{fournel_c3-symmetric_2005,
title = {C3-symmetric peptide scaffolds are functional mimetics of trimeric CD40L},
author = {Sylvie Fournel and Sébastien Wieckowski and Weimin Sun and Nathalie Trouche and Hélène Dumortier and Alberto Bianco and Olivier Chaloin and Mohammed Habib and Jean-Christophe Peter and Pascal Schneider and Bernard Vray and René E Toes and Rienk Offringa and Cornelis J M Melief and Johan Hoebeke and Gilles Guichard},
doi = {10.1038/nchembio746},
issn = {1552-4450},
year = {2005},
date = {2005-12-01},
journal = {Nature Chemical Biology},
volume = {1},
number = {7},
pages = {377--382},
abstract = {Interaction between CD40, a member of the tumor necrosis factor receptor (TNFR) superfamily, and its ligand CD40L, a 39-kDa glycoprotein, is essential for the development of humoral and cellular immune responses. Selective blockade or activation of this pathway provides the ground for the development of new treatments against immunologically based diseases and malignancies. Like other members of the TNF superfamily, CD40L monomers self-assemble around a threefold symmetry axis to form noncovalent homotrimers that can each bind three receptor molecules. Here, we report on the structure-based design of small synthetic molecules with C3 symmetry that can mimic CD40L homotrimers. These molecules interact with CD40, compete with the binding of CD40L to CD40, and reproduce, to a certain extent, the functional properties of the much larger homotrimeric soluble CD40L. Architectures based on rigid C3-symmetric cores may thus represent a general approach to mimicking homotrimers of the TNF superfamily.},
keywords = {Animals, Apoptosis, Biological, CD40 Antigens, CD40 Ligand, Cell Line, Dumortier, Humans, I2CT, Inbred BALB C, Mice, Models, Molecular Mimicry, Molecular Structure, Peptides, Protein Conformation, Protein Structure, Quaternary, Structure-Activity Relationship, Team-Bianco, Team-Dumortier, Time Factors, tumor},
pubstate = {published},
tppubtype = {article}
}
Interaction between CD40, a member of the tumor necrosis factor receptor (TNFR) superfamily, and its ligand CD40L, a 39-kDa glycoprotein, is essential for the development of humoral and cellular immune responses. Selective blockade or activation of this pathway provides the ground for the development of new treatments against immunologically based diseases and malignancies. Like other members of the TNF superfamily, CD40L monomers self-assemble around a threefold symmetry axis to form noncovalent homotrimers that can each bind three receptor molecules. Here, we report on the structure-based design of small synthetic molecules with C3 symmetry that can mimic CD40L homotrimers. These molecules interact with CD40, compete with the binding of CD40L to CD40, and reproduce, to a certain extent, the functional properties of the much larger homotrimeric soluble CD40L. Architectures based on rigid C3-symmetric cores may thus represent a general approach to mimicking homotrimers of the TNF superfamily.
Weber Alexander N R, Moncrieffe Martin C, Gangloff Monique, Imler Jean-Luc, Gay Nicholas J
Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway Article de journal
Dans: The Journal of Biological Chemistry, vol. 280, no. 24, p. 22793–22799, 2005, ISSN: 0021-9258.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation
@article{weber_ligand-receptor_2005,
title = {Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway},
author = {Alexander N R Weber and Martin C Moncrieffe and Monique Gangloff and Jean-Luc Imler and Nicholas J Gay},
doi = {10.1074/jbc.M502074200},
issn = {0021-9258},
year = {2005},
date = {2005-01-01},
journal = {The Journal of Biological Chemistry},
volume = {280},
number = {24},
pages = {22793--22799},
abstract = {In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions.},
keywords = {Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation},
pubstate = {published},
tppubtype = {article}
}
In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions.
Dumortier Hélène, van Mierlo Geertje J D, Egan Deirdre, van Ewijk Willem, Toes René E M, Offringa Rienk, Melief Cornelis J M
Dans: Journal of Immunology (Baltimore, Md.: 1950), vol. 175, no. 2, p. 855–863, 2005, ISSN: 0022-1767.
Résumé | Liens | BibTeX | Étiquettes: Adenovirus E1A Proteins, Animals, Antigen, Antigen Presentation, CD8-Positive T-Lymphocytes, Cell Differentiation, Cell Line, Cell Movement, Clonal Deletion, Cytotoxic, Cytotoxicity, Dendritic Cells, Down-Regulation, Dumortier, Epitopes, Female, I2CT, Immunologic, Immunologic Memory, Inbred C57BL, Lipopolysaccharides, Lymphocyte Activation, Mice, Myeloid Cells, Receptors, Regulatory, T-Cell, T-Lymphocyte, T-Lymphocytes, Team-Dumortier, transgenic
@article{dumortier_antigen_2005,
title = {Antigen presentation by an immature myeloid dendritic cell line does not cause CTL deletion in vivo, but generates CD8+ central memory-like Ŧ cells that can be rescued for full effector function},
author = {Hélène Dumortier and Geertje J D van Mierlo and Deirdre Egan and Willem van Ewijk and René E M Toes and Rienk Offringa and Cornelis J M Melief},
doi = {10.4049/jimmunol.175.2.855},
issn = {0022-1767},
year = {2005},
date = {2005-01-01},
journal = {Journal of Immunology (Baltimore, Md.: 1950)},
volume = {175},
number = {2},
pages = {855--863},
abstract = {Immature dendritic cells (DC), in contrast to their mature counterparts, are incapable of mobilizing a CD8+ CTL response, and, instead, have been reported to induce CTL tolerance. We directly addressed the impact of immature vs mature DC on CTL responses by infusing adenovirus peptide-loaded DC (of the D1 cell line) into mice that had received adenovirus-specific naive TCR-transgenic CD8+ T cells. Whereas i.v. injection of mature DC triggered vigorous CTL expansion, immature DC elicited little proliferation involving only a minority of the TCR-transgenic CTL. Even though the latter CTL developed effector functions, including cytolytic activity and proinflammatory cytokine secretion, these cells differed significantly from CTL primed by mature DC in that they did not exhibit down-regulation of CD62L and CCR7, receptors involved in trapping of T cells in the lymphoid organs. Interestingly, adoptive transfer of CTL effector cells harvested after priming by either mature or immature DC into naive recipient mice, followed by exposure to adenovirus, yielded quantitatively and qualitatively indistinguishable CTL memory responses. Therefore, in vivo priming of naive CD8+ T cells by immature DC, although failing to induce a full-blown, systemic CTL response, resulted in the formation of central memory-like T cells that were able to expand and produce IFN-gamma upon secondary antigenic stimulation.},
keywords = {Adenovirus E1A Proteins, Animals, Antigen, Antigen Presentation, CD8-Positive T-Lymphocytes, Cell Differentiation, Cell Line, Cell Movement, Clonal Deletion, Cytotoxic, Cytotoxicity, Dendritic Cells, Down-Regulation, Dumortier, Epitopes, Female, I2CT, Immunologic, Immunologic Memory, Inbred C57BL, Lipopolysaccharides, Lymphocyte Activation, Mice, Myeloid Cells, Receptors, Regulatory, T-Cell, T-Lymphocyte, T-Lymphocytes, Team-Dumortier, transgenic},
pubstate = {published},
tppubtype = {article}
}
Immature dendritic cells (DC), in contrast to their mature counterparts, are incapable of mobilizing a CD8+ CTL response, and, instead, have been reported to induce CTL tolerance. We directly addressed the impact of immature vs mature DC on CTL responses by infusing adenovirus peptide-loaded DC (of the D1 cell line) into mice that had received adenovirus-specific naive TCR-transgenic CD8+ T cells. Whereas i.v. injection of mature DC triggered vigorous CTL expansion, immature DC elicited little proliferation involving only a minority of the TCR-transgenic CTL. Even though the latter CTL developed effector functions, including cytolytic activity and proinflammatory cytokine secretion, these cells differed significantly from CTL primed by mature DC in that they did not exhibit down-regulation of CD62L and CCR7, receptors involved in trapping of T cells in the lymphoid organs. Interestingly, adoptive transfer of CTL effector cells harvested after priming by either mature or immature DC into naive recipient mice, followed by exposure to adenovirus, yielded quantitatively and qualitatively indistinguishable CTL memory responses. Therefore, in vivo priming of naive CD8+ T cells by immature DC, although failing to induce a full-blown, systemic CTL response, resulted in the formation of central memory-like T cells that were able to expand and produce IFN-gamma upon secondary antigenic stimulation.
Fournel Sylvie, Wieckowski Sébastien, Sun Weimin, Trouche Nathalie, Dumortier Hélène, Bianco Alberto, Chaloin Olivier, Habib Mohammed, Peter Jean-Christophe, Schneider Pascal, Vray Bernard, Toes René E, Offringa Rienk, Melief Cornelis J M, Hoebeke Johan, Guichard Gilles
C3-symmetric peptide scaffolds are functional mimetics of trimeric CD40L Article de journal
Dans: Nature Chemical Biology, vol. 1, no. 7, p. 377–382, 2005, ISSN: 1552-4450.
Résumé | Liens | BibTeX | Étiquettes: Animals, Apoptosis, Biological, CD40 Antigens, CD40 Ligand, Cell Line, Humans, I2CT, Inbred BALB C, Mice, Models, Molecular Mimicry, Molecular Structure, Peptides, Protein Conformation, Protein Structure, Quaternary, Structure-Activity Relationship, Team-Bianco, Time Factors, tumor
@article{fournel_c3-symmetric_2005b,
title = {C3-symmetric peptide scaffolds are functional mimetics of trimeric CD40L},
author = {Sylvie Fournel and Sébastien Wieckowski and Weimin Sun and Nathalie Trouche and Hélène Dumortier and Alberto Bianco and Olivier Chaloin and Mohammed Habib and Jean-Christophe Peter and Pascal Schneider and Bernard Vray and René E Toes and Rienk Offringa and Cornelis J M Melief and Johan Hoebeke and Gilles Guichard},
doi = {10.1038/nchembio746},
issn = {1552-4450},
year = {2005},
date = {2005-01-01},
journal = {Nature Chemical Biology},
volume = {1},
number = {7},
pages = {377--382},
abstract = {Interaction between CD40, a member of the tumor necrosis factor receptor (TNFR) superfamily, and its ligand CD40L, a 39-kDa glycoprotein, is essential for the development of humoral and cellular immune responses. Selective blockade or activation of this pathway provides the ground for the development of new treatments against immunologically based diseases and malignancies. Like other members of the TNF superfamily, CD40L monomers self-assemble around a threefold symmetry axis to form noncovalent homotrimers that can each bind three receptor molecules. Here, we report on the structure-based design of small synthetic molecules with C3 symmetry that can mimic CD40L homotrimers. These molecules interact with CD40, compete with the binding of CD40L to CD40, and reproduce, to a certain extent, the functional properties of the much larger homotrimeric soluble CD40L. Architectures based on rigid C3-symmetric cores may thus represent a general approach to mimicking homotrimers of the TNF superfamily.},
keywords = {Animals, Apoptosis, Biological, CD40 Antigens, CD40 Ligand, Cell Line, Humans, I2CT, Inbred BALB C, Mice, Models, Molecular Mimicry, Molecular Structure, Peptides, Protein Conformation, Protein Structure, Quaternary, Structure-Activity Relationship, Team-Bianco, Time Factors, tumor},
pubstate = {published},
tppubtype = {article}
}
Interaction between CD40, a member of the tumor necrosis factor receptor (TNFR) superfamily, and its ligand CD40L, a 39-kDa glycoprotein, is essential for the development of humoral and cellular immune responses. Selective blockade or activation of this pathway provides the ground for the development of new treatments against immunologically based diseases and malignancies. Like other members of the TNF superfamily, CD40L monomers self-assemble around a threefold symmetry axis to form noncovalent homotrimers that can each bind three receptor molecules. Here, we report on the structure-based design of small synthetic molecules with C3 symmetry that can mimic CD40L homotrimers. These molecules interact with CD40, compete with the binding of CD40L to CD40, and reproduce, to a certain extent, the functional properties of the much larger homotrimeric soluble CD40L. Architectures based on rigid C3-symmetric cores may thus represent a general approach to mimicking homotrimers of the TNF superfamily.
2000
Tauszig Servane, Jouanguy Emmanuelle, Hoffmann Jules A, Imler Jean-Luc
Toll-related receptors and the control of antimicrobial peptide expression in Drosophila Article de journal
Dans: Proceedings of the National Academy of Sciences of the United States of America, vol. 97, no. 19, p. 10520–10525, 2000, ISSN: 0027-8424.