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2010
Matskevich Alexey A, Quintin Jessica, Ferrandon Dominique
The Drosophila PRR GNBP3 assembles effector complexes involved in antifungal defenses independently of its Toll-pathway activation function Article de journal
Dans: Eur. J. Immunol., vol. 40, no. 5, p. 1244–1254, 2010, ISSN: 1521-4141.
Résumé | Liens | BibTeX | Étiquettes: Agglutination, Animals, Beauveria, Beauveria/immunology, Candida albicans, Candida albicans/immunology, Carrier Proteins, Carrier Proteins/*immunology/pharmacology, Drosophila melanogaster/*immunology/microbiology, Drosophila Proteins/*immunology/pharmacology/physiology, Enzyme Activation, ferrandon, Fungal, Fungi, Fungi/*immunology, Hemolymph, Hemolymph/immunology, M3i, Melanins, Melanins/*physiology, Monophenol Monooxygenase, Monophenol Monooxygenase/physiology, Multiprotein Complexes, Multiprotein Complexes/physiology, Recombinant Fusion Proteins, Recombinant Fusion Proteins/pharmacology, Serpins, Serpins/physiology, Spores, Toll-Like Receptors, Toll-Like Receptors/immunology
@article{matskevich_drosophila_2010b,
title = {The Drosophila PRR GNBP3 assembles effector complexes involved in antifungal defenses independently of its Toll-pathway activation function},
author = {Alexey A Matskevich and Jessica Quintin and Dominique Ferrandon},
doi = {10.1002/eji.200940164},
issn = {1521-4141},
year = {2010},
date = {2010-05-01},
journal = {Eur. J. Immunol.},
volume = {40},
number = {5},
pages = {1244--1254},
abstract = {The Drosophila Toll-signaling pathway controls the systemic antifungal host response. Gram-negative binding protein 3 (GNBP3), a member of the beta-glucan recognition protein family senses fungal infections and activates this pathway. A second detection system perceives the activity of proteolytic fungal virulence factors and redundantly activates Toll. GNBP3(hades) mutant flies succumb more rapidly to Candida albicans and to entomopathogenic fungal infections than WT flies, despite normal triggering of the Toll pathway via the virulence detection system. These observations suggest that GNBP3 triggers antifungal defenses that are not dependent on activation of the Toll pathway. Here, we show that GNBP3 agglutinates fungal cells. Furthermore, it can activate melanization in a Toll-independent manner. Melanization is likely to be an essential defense against some fungal infections given that the entomopathogenic fungus Beauveria bassiana inhibits the activity of the main melanization enzymes, the phenol oxidases. Finally, we show that GNBP3 assembles "attack complexes", which comprise phenoloxidase and the necrotic serpin. We propose that Drosophila GNBP3 targets fungi immediately at the inception of the infection by bringing effector molecules in direct contact with the invading microorganisms.},
keywords = {Agglutination, Animals, Beauveria, Beauveria/immunology, Candida albicans, Candida albicans/immunology, Carrier Proteins, Carrier Proteins/*immunology/pharmacology, Drosophila melanogaster/*immunology/microbiology, Drosophila Proteins/*immunology/pharmacology/physiology, Enzyme Activation, ferrandon, Fungal, Fungi, Fungi/*immunology, Hemolymph, Hemolymph/immunology, M3i, Melanins, Melanins/*physiology, Monophenol Monooxygenase, Monophenol Monooxygenase/physiology, Multiprotein Complexes, Multiprotein Complexes/physiology, Recombinant Fusion Proteins, Recombinant Fusion Proteins/pharmacology, Serpins, Serpins/physiology, Spores, Toll-Like Receptors, Toll-Like Receptors/immunology},
pubstate = {published},
tppubtype = {article}
}
The Drosophila Toll-signaling pathway controls the systemic antifungal host response. Gram-negative binding protein 3 (GNBP3), a member of the beta-glucan recognition protein family senses fungal infections and activates this pathway. A second detection system perceives the activity of proteolytic fungal virulence factors and redundantly activates Toll. GNBP3(hades) mutant flies succumb more rapidly to Candida albicans and to entomopathogenic fungal infections than WT flies, despite normal triggering of the Toll pathway via the virulence detection system. These observations suggest that GNBP3 triggers antifungal defenses that are not dependent on activation of the Toll pathway. Here, we show that GNBP3 agglutinates fungal cells. Furthermore, it can activate melanization in a Toll-independent manner. Melanization is likely to be an essential defense against some fungal infections given that the entomopathogenic fungus Beauveria bassiana inhibits the activity of the main melanization enzymes, the phenol oxidases. Finally, we show that GNBP3 assembles "attack complexes", which comprise phenoloxidase and the necrotic serpin. We propose that Drosophila GNBP3 targets fungi immediately at the inception of the infection by bringing effector molecules in direct contact with the invading microorganisms.
1998
Braun A, Hoffmann Jules A, Meister Marie
Analysis of the Drosophila host defense in domino mutant larvae, which are devoid of hemocytes Article de journal
Dans: Proc. Natl. Acad. Sci. U.S.A., vol. 95, no. 24, p. 14337–14342, 1998, ISSN: 0027-8424.
Résumé | BibTeX | Étiquettes: Adipose Tissue, Animals, Candida, Escherichia coli, Fungal, Genotype, Hemocytes, hoffmann, Larva, M3i, Melanins, Micrococcus luteus, Spores
@article{braun_analysis_1998,
title = {Analysis of the Drosophila host defense in domino mutant larvae, which are devoid of hemocytes},
author = {A Braun and Jules A Hoffmann and Marie Meister},
issn = {0027-8424},
year = {1998},
date = {1998-11-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {95},
number = {24},
pages = {14337--14342},
abstract = {We have analyzed the Drosophila immune response in domino mutant larvae, which are devoid of blood cells. The domino mutants have a good larval viability, but they die as prepupae. We show that, on immune challenge, induction of the genes encoding antimicrobial peptides in the fat body is not affected significantly in the mutant larvae, indicating that hemocytes are not essential in this process. The hemocoele of domino larvae contains numerous live microorganisms, the presence of which induces a weak antimicrobial response in the fat body. A full response is observed only after septic injury. We propose that the fat body cells are activated both by the presence of microorganisms and by injury and that injury potentiates the effect of microorganisms. Survival experiments after an immune challenge showed that domino mutants devoid of blood cells maintain a wild-type resistance to septic injury. This resistance was also observed in mutant larvae in which the synthesis of antibacterial peptides is impaired (immune deficiency larvae) and in mutants that are deficient for humoral melanization (Black cells larvae). However, if domino was combined with either the immune deficiency or the Black cell mutation, the resistance to septic injury was reduced severely. These results establish the relevance of the three immune reactions: phagocytosis, synthesis of antibacterial peptides, and melanization. By working in synergy, they provide Drosophila a highly effective defense against injury and/or infection.},
keywords = {Adipose Tissue, Animals, Candida, Escherichia coli, Fungal, Genotype, Hemocytes, hoffmann, Larva, M3i, Melanins, Micrococcus luteus, Spores},
pubstate = {published},
tppubtype = {article}
}
We have analyzed the Drosophila immune response in domino mutant larvae, which are devoid of blood cells. The domino mutants have a good larval viability, but they die as prepupae. We show that, on immune challenge, induction of the genes encoding antimicrobial peptides in the fat body is not affected significantly in the mutant larvae, indicating that hemocytes are not essential in this process. The hemocoele of domino larvae contains numerous live microorganisms, the presence of which induces a weak antimicrobial response in the fat body. A full response is observed only after septic injury. We propose that the fat body cells are activated both by the presence of microorganisms and by injury and that injury potentiates the effect of microorganisms. Survival experiments after an immune challenge showed that domino mutants devoid of blood cells maintain a wild-type resistance to septic injury. This resistance was also observed in mutant larvae in which the synthesis of antibacterial peptides is impaired (immune deficiency larvae) and in mutants that are deficient for humoral melanization (Black cells larvae). However, if domino was combined with either the immune deficiency or the Black cell mutation, the resistance to septic injury was reduced severely. These results establish the relevance of the three immune reactions: phagocytosis, synthesis of antibacterial peptides, and melanization. By working in synergy, they provide Drosophila a highly effective defense against injury and/or infection.
Ferrandon Dominique, Jung Alain C, Criqui M, Lemaitre Bruno, Uttenweiler-Joseph S, Michaut Lydia, Reichhart Jean-Marc, Hoffmann Jules A
A drosomycin-GFP reporter transgene reveals a local immune response in Drosophila that is not dependent on the Toll pathway Article de journal
Dans: EMBO J., vol. 17, no. 5, p. 1217–1227, 1998, ISSN: 0261-4189.
Résumé | Liens | BibTeX | Étiquettes: Animals, bacteria, Cell Surface, Developmental, Digestive System, Epithelium, Fat Body, Female, ferrandon, Fungal, Gene Expression Regulation, Genes, Green Fluorescent Proteins, hoffmann, Insect Proteins, Larva, Luminescent Proteins, M3i, Male, Membrane Glycoproteins, Organ Specificity, Receptors, reichhart, Reporter, Respiratory System, Spores, Toll-Like Receptors, Trachea, Transgenes
@article{ferrandon_drosomycin-gfp_1998,
title = {A drosomycin-GFP reporter transgene reveals a local immune response in Drosophila that is not dependent on the Toll pathway},
author = {Dominique Ferrandon and Alain C Jung and M Criqui and Bruno Lemaitre and S Uttenweiler-Joseph and Lydia Michaut and Jean-Marc Reichhart and Jules A Hoffmann},
doi = {10.1093/emboj/17.5.1217},
issn = {0261-4189},
year = {1998},
date = {1998-08-01},
journal = {EMBO J.},
volume = {17},
number = {5},
pages = {1217--1227},
abstract = {A hallmark of the systemic antimicrobial response of Drosophila is the synthesis by the fat body of several antimicrobial peptides which are released into the hemolymph in response to a septic injury. One of these peptides, drosomycin, is active primarily against fungi. Using a drosomycin-green fluorescent protein (GFP) reporter gene, we now show that in addition to the fat body, a variety of epithelial tissues that are in direct contact with the external environment, including those of the respiratory, digestive and reproductive tracts, can express the antifungal peptide, suggesting a local response to infections affecting these barrier tissues. As is the case for vertebrate epithelia, insect epithelia appear to be more than passive physical barriers and are likely to constitute an active component of innate immunity. We also show that, in contrast to the systemic antifungal response, this local immune response is independent of the Toll pathway.},
keywords = {Animals, bacteria, Cell Surface, Developmental, Digestive System, Epithelium, Fat Body, Female, ferrandon, Fungal, Gene Expression Regulation, Genes, Green Fluorescent Proteins, hoffmann, Insect Proteins, Larva, Luminescent Proteins, M3i, Male, Membrane Glycoproteins, Organ Specificity, Receptors, reichhart, Reporter, Respiratory System, Spores, Toll-Like Receptors, Trachea, Transgenes},
pubstate = {published},
tppubtype = {article}
}
A hallmark of the systemic antimicrobial response of Drosophila is the synthesis by the fat body of several antimicrobial peptides which are released into the hemolymph in response to a septic injury. One of these peptides, drosomycin, is active primarily against fungi. Using a drosomycin-green fluorescent protein (GFP) reporter gene, we now show that in addition to the fat body, a variety of epithelial tissues that are in direct contact with the external environment, including those of the respiratory, digestive and reproductive tracts, can express the antifungal peptide, suggesting a local response to infections affecting these barrier tissues. As is the case for vertebrate epithelia, insect epithelia appear to be more than passive physical barriers and are likely to constitute an active component of innate immunity. We also show that, in contrast to the systemic antifungal response, this local immune response is independent of the Toll pathway.
