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2011
Aoun Richard Bou, Hetru Charles, Troxler Laurent, Doucet Daniel, Ferrandon Dominique, Matt Nicolas
Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster Journal Article
In: J Innate Immun, vol. 3, no. 1, pp. 52–64, 2011, ISSN: 1662-8128.
Abstract | Links | BibTeX | Tags: Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis
@article{bou_aoun_analysis_2011,
title = {Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster},
author = {Richard Bou Aoun and Charles Hetru and Laurent Troxler and Daniel Doucet and Dominique Ferrandon and Nicolas Matt},
doi = {10.1159/000321554},
issn = {1662-8128},
year = {2011},
date = {2011-01-01},
journal = {J Innate Immun},
volume = {3},
number = {1},
pages = {52--64},
abstract = {Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila.},
keywords = {Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis},
pubstate = {published},
tppubtype = {article}
}
Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila.
2008
Chamy L El, Leclerc V, Caldelari I, Reichhart J-M
Sensing of 'danger signals' and pathogen-associated molecular patterns defines binary signaling pathways 'upstream' of Toll Journal Article
In: Nat. Immunol., vol. 9, no. 10, pp. 1165–1170, 2008, ISSN: 1529-2916.
Abstract | Links | BibTeX | Tags: Animals, Fungi, Genetically Modified, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, In Situ Hybridization, M3i, Mycoses, Pattern Recognition, Peptide Hydrolases, Receptors, reichhart, ROMBY, Serine Endopeptidases, Signal Transduction, Toll-Like Receptors, Unité ARN
@article{el_chamy_sensing_2008,
title = {Sensing of 'danger signals' and pathogen-associated molecular patterns defines binary signaling pathways 'upstream' of Toll},
author = {L El Chamy and V Leclerc and I Caldelari and J-M Reichhart},
doi = {10.1038/ni.1643},
issn = {1529-2916},
year = {2008},
date = {2008-10-01},
journal = {Nat. Immunol.},
volume = {9},
number = {10},
pages = {1165--1170},
abstract = {In drosophila, molecular determinants from fungi and Gram-positive bacteria are detected by circulating pattern-recognition receptors. Published findings suggest that such pattern-recognition receptors activate as-yet-unidentified serine-protease cascades that culminate in the cleavage of Spätzle, the endogenous Toll receptor ligand, and trigger the immune response. We demonstrate here that the protease Grass defines a common activation cascade for the detection of fungi and Gram-positive bacteria mediated by pattern-recognition receptors. The serine protease Persephone, shown before to be specific for fungal detection in a cascade activated by secreted fungal proteases, was also required for the sensing of proteases elicited by bacteria in the hemolymph. Hence, Persephone defines a parallel proteolytic cascade activated by 'danger signals' such as abnormal proteolytic activities.},
keywords = {Animals, Fungi, Genetically Modified, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, In Situ Hybridization, M3i, Mycoses, Pattern Recognition, Peptide Hydrolases, Receptors, reichhart, ROMBY, Serine Endopeptidases, Signal Transduction, Toll-Like Receptors, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
In drosophila, molecular determinants from fungi and Gram-positive bacteria are detected by circulating pattern-recognition receptors. Published findings suggest that such pattern-recognition receptors activate as-yet-unidentified serine-protease cascades that culminate in the cleavage of Spätzle, the endogenous Toll receptor ligand, and trigger the immune response. We demonstrate here that the protease Grass defines a common activation cascade for the detection of fungi and Gram-positive bacteria mediated by pattern-recognition receptors. The serine protease Persephone, shown before to be specific for fungal detection in a cascade activated by secreted fungal proteases, was also required for the sensing of proteases elicited by bacteria in the hemolymph. Hence, Persephone defines a parallel proteolytic cascade activated by 'danger signals' such as abnormal proteolytic activities.
2005
Kocks Christine, Cho Ju Hyun, Nehme Nadine, Ulvila Johanna, Pearson Alan M, Meister Marie, Strom Charles, Conto Stephanie L, Hetru Charles, Stuart Lynda M, Stehle Thilo, Hoffmann Jules A, Reichhart Jean-Marc, Ferrandon Dominique, Rämet Mika, Ezekowitz Alan R B
Eater, a transmembrane protein mediating phagocytosis of bacterial pathogens in Drosophila Journal Article
In: Cell, vol. 123, no. 2, pp. 335–346, 2005, ISSN: 0092-8674.
Abstract | Links | BibTeX | Tags: Amino Acid, Amino Acid Motifs, Animals, Bacterial Infections, Cell Surface, Embryo, Escherichia coli, ferrandon, Flow Cytometry, Frameshift Mutation, Genes, Histidine, hoffmann, In Situ Hybridization, Insect, Insect Proteins, M3i, Macrophages, Membrane Proteins, messenger, Nonmammalian, Open Reading Frames, Phagocytosis, Receptors, reichhart, RNA, RNA Interference, Sequence Homology, Serratia marcescens
@article{kocks_eater_2005,
title = {Eater, a transmembrane protein mediating phagocytosis of bacterial pathogens in Drosophila},
author = {Christine Kocks and Ju Hyun Cho and Nadine Nehme and Johanna Ulvila and Alan M Pearson and Marie Meister and Charles Strom and Stephanie L Conto and Charles Hetru and Lynda M Stuart and Thilo Stehle and Jules A Hoffmann and Jean-Marc Reichhart and Dominique Ferrandon and Mika Rämet and Alan R B Ezekowitz},
doi = {10.1016/j.cell.2005.08.034},
issn = {0092-8674},
year = {2005},
date = {2005-10-01},
journal = {Cell},
volume = {123},
number = {2},
pages = {335--346},
abstract = {Phagocytosis is a complex, evolutionarily conserved process that plays a central role in host defense against infection. We have identified a predicted transmembrane protein, Eater, which is involved in phagocytosis in Drosophila. Transcriptional silencing of the eater gene in a macrophage cell line led to a significant reduction in the binding and internalization of bacteria. Moreover, the N terminus of the Eater protein mediated direct microbial binding which could be inhibited with scavenger receptor ligands, acetylated, and oxidized low-density lipoprotein. In vivo, eater expression was restricted to blood cells. Flies lacking the eater gene displayed normal responses in NF-kappaB-like Toll and IMD signaling pathways but showed impaired phagocytosis and decreased survival after bacterial infection. Our results suggest that Eater is a major phagocytic receptor for a broad range of bacterial pathogens in Drosophila and provide a powerful model to address the role of phagocytosis in vivo.},
keywords = {Amino Acid, Amino Acid Motifs, Animals, Bacterial Infections, Cell Surface, Embryo, Escherichia coli, ferrandon, Flow Cytometry, Frameshift Mutation, Genes, Histidine, hoffmann, In Situ Hybridization, Insect, Insect Proteins, M3i, Macrophages, Membrane Proteins, messenger, Nonmammalian, Open Reading Frames, Phagocytosis, Receptors, reichhart, RNA, RNA Interference, Sequence Homology, Serratia marcescens},
pubstate = {published},
tppubtype = {article}
}
Phagocytosis is a complex, evolutionarily conserved process that plays a central role in host defense against infection. We have identified a predicted transmembrane protein, Eater, which is involved in phagocytosis in Drosophila. Transcriptional silencing of the eater gene in a macrophage cell line led to a significant reduction in the binding and internalization of bacteria. Moreover, the N terminus of the Eater protein mediated direct microbial binding which could be inhibited with scavenger receptor ligands, acetylated, and oxidized low-density lipoprotein. In vivo, eater expression was restricted to blood cells. Flies lacking the eater gene displayed normal responses in NF-kappaB-like Toll and IMD signaling pathways but showed impaired phagocytosis and decreased survival after bacterial infection. Our results suggest that Eater is a major phagocytic receptor for a broad range of bacterial pathogens in Drosophila and provide a powerful model to address the role of phagocytosis in vivo.