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2005
Imler Jean-Luc, Bulet Philippe
Antimicrobial peptides in Drosophila: structures, activities and gene regulation Article de journal
Dans: Chemical Immunology and Allergy, vol. 86, p. 1–21, 2005, ISSN: 1660-2242.
Résumé | Liens | BibTeX | Étiquettes: Animals, Antimicrobial Cationic Peptides, Defensins, Gene Expression Regulation, Genes, Glycopeptides, imler, Immunity, Innate, Insect, Insect Proteins, M3i, Molecular Structure, Signal Transduction
@article{imler_antimicrobial_2005,
title = {Antimicrobial peptides in Drosophila: structures, activities and gene regulation},
author = {Jean-Luc Imler and Philippe Bulet},
doi = {10.1159/000086648},
issn = {1660-2242},
year = {2005},
date = {2005-01-01},
journal = {Chemical Immunology and Allergy},
volume = {86},
pages = {1--21},
abstract = {The production of antimicrobial peptides (AMPs) is an important aspect of host-defence in multicellular organisms. Biochemical analysis of the hemolymph of the fruit-fly Drosophila melanogaster and other Diptera has led to the discovery of eight classes of AMPs. These peptides can be grouped into three families based on their main biological targets, gram-positive bacteria (defensin), gram-negative bacteria (cecropins, drosocin, attacins, diptericin, MPAC), or fungi (drosomycin, metchnikowin). Drosophila AMPs are synthesized by the fat body in response to infection, and secreted into the blood. Most of them can also be induced in surface epithelia in a tissue-specific manner. Finally, some of them are constitutively expressed in defined tissues, such as the salivary glands or the reproductive tract. We review here the structures and activities of these AMPs, as well as the signalling cascades, which lead to their induction upon detection of infectious non-self.},
keywords = {Animals, Antimicrobial Cationic Peptides, Defensins, Gene Expression Regulation, Genes, Glycopeptides, imler, Immunity, Innate, Insect, Insect Proteins, M3i, Molecular Structure, Signal Transduction},
pubstate = {published},
tppubtype = {article}
}
The production of antimicrobial peptides (AMPs) is an important aspect of host-defence in multicellular organisms. Biochemical analysis of the hemolymph of the fruit-fly Drosophila melanogaster and other Diptera has led to the discovery of eight classes of AMPs. These peptides can be grouped into three families based on their main biological targets, gram-positive bacteria (defensin), gram-negative bacteria (cecropins, drosocin, attacins, diptericin, MPAC), or fungi (drosomycin, metchnikowin). Drosophila AMPs are synthesized by the fat body in response to infection, and secreted into the blood. Most of them can also be induced in surface epithelia in a tissue-specific manner. Finally, some of them are constitutively expressed in defined tissues, such as the salivary glands or the reproductive tract. We review here the structures and activities of these AMPs, as well as the signalling cascades, which lead to their induction upon detection of infectious non-self.
2001
Boulanger Nathalie, Ehret-Sabatier Laurence, Brun R, Zachary Daniel, Bulet Philippe, Imler Jean-Luc
Immune response of Drosophila melanogaster to infection with the flagellate parasite Crithidia spp Article de journal
Dans: Insect Biochemistry and Molecular Biology, vol. 31, no. 2, p. 129–137, 2001, ISSN: 0965-1748.
Résumé | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Crithidia, Defensins, Gene Expression, Glycopeptides, Hemocytes, imler, Insect Proteins, M3i, Phagocytosis
@article{boulanger_immune_2001,
title = {Immune response of Drosophila melanogaster to infection with the flagellate parasite Crithidia spp},
author = {Nathalie Boulanger and Laurence Ehret-Sabatier and R Brun and Daniel Zachary and Philippe Bulet and Jean-Luc Imler},
issn = {0965-1748},
year = {2001},
date = {2001-02-01},
journal = {Insect Biochemistry and Molecular Biology},
volume = {31},
number = {2},
pages = {129--137},
abstract = {Insects are able to recognize invading microorganisms and to mount an immune response to bacterial and fungal infections. Recently, the fruitfly Drosophila melanogaster has emerged as a promising invertebrate model to investigate innate immunity because of its well-characterized genetics. Insects are also vectors of numerous parasites which can trigger an immune response. We have investigated the interaction of Drosophila melanogaster with the flagellate protozoan Crithidia spp. We show that a per os parasitic infection triggers the synthesis of several antimicrobial peptides. By reverse phase HPLC and mass spectrometry, peptides were shown to be present in the hemolymph and not in the gut tissue, suggesting the presence of immune messengers between the site of the infection, namely the gut, and the fat body, the main site of synthesis for antimicrobial peptides. Interestingly, we have identified one molecule which is specifically induced in the hemolymph after infection with Crithidia, but not with bacteria, suggesting that Drosophila can discriminate between pathogens. When flagellates were injected into the hemolymph, a low synthesis of antimicrobial peptides was observed together with phagocytosis of parasites by circulating hemocytes. The data presented here suggest that Drosophila-Crithidia spp. represents an interesting model to study host defense against protozoan parasites.},
keywords = {Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Crithidia, Defensins, Gene Expression, Glycopeptides, Hemocytes, imler, Insect Proteins, M3i, Phagocytosis},
pubstate = {published},
tppubtype = {article}
}
Insects are able to recognize invading microorganisms and to mount an immune response to bacterial and fungal infections. Recently, the fruitfly Drosophila melanogaster has emerged as a promising invertebrate model to investigate innate immunity because of its well-characterized genetics. Insects are also vectors of numerous parasites which can trigger an immune response. We have investigated the interaction of Drosophila melanogaster with the flagellate protozoan Crithidia spp. We show that a per os parasitic infection triggers the synthesis of several antimicrobial peptides. By reverse phase HPLC and mass spectrometry, peptides were shown to be present in the hemolymph and not in the gut tissue, suggesting the presence of immune messengers between the site of the infection, namely the gut, and the fat body, the main site of synthesis for antimicrobial peptides. Interestingly, we have identified one molecule which is specifically induced in the hemolymph after infection with Crithidia, but not with bacteria, suggesting that Drosophila can discriminate between pathogens. When flagellates were injected into the hemolymph, a low synthesis of antimicrobial peptides was observed together with phagocytosis of parasites by circulating hemocytes. The data presented here suggest that Drosophila-Crithidia spp. represents an interesting model to study host defense against protozoan parasites.
1998
Levashina Elena A, Ohresser S, Lemaitre Bruno, Imler Jean-Luc
Two distinct pathways can control expression of the gene encoding the Drosophila antimicrobial peptide metchnikowin Article de journal
Dans: Journal of Molecular Biology, vol. 278, no. 3, p. 515–527, 1998, ISSN: 0022-2836.
Résumé | Liens | BibTeX | Étiquettes: Animals, Anti-Infective Agents, Antimicrobial Cationic Peptides, Base Sequence, Cloning, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Glycopeptides, imler, Insect, Insect Proteins, Larva, M3i, Molecular, Mutation, Peptides, Promoter Regions, Recombinant Fusion Proteins, Reporter, Restriction Mapping, Transcription
@article{levashina_two_1998,
title = {Two distinct pathways can control expression of the gene encoding the Drosophila antimicrobial peptide metchnikowin},
author = {Elena A Levashina and S Ohresser and Bruno Lemaitre and Jean-Luc Imler},
doi = {10.1006/jmbi.1998.1705},
issn = {0022-2836},
year = {1998},
date = {1998-01-01},
journal = {Journal of Molecular Biology},
volume = {278},
number = {3},
pages = {515--527},
abstract = {Metchnikowin is a recently discovered proline-rich peptide from Drosophila with antibacterial and antifungal properties. Like most other antimicrobial peptides from insects, its expression is immune-inducible. Here we present evidence that induction of metchnikowin gene expression can be mediated either by the TOLL pathway or by the imd gene product. We show that the gene remains inducible in Toll-deficient mutants, in which the antifungal response is blocked, as well as in imd mutants, which fail to mount an antibacterial response. However, in Toll-deficient;imd double mutants, metchnikowin gene expression can no longer be detected after immune challenge. Our results suggest that expression of this peptide with dual activity can be triggered by signals generated by either bacterial or fungal infection. Cloning of the metchnikowin gene revealed the presence in the 5' flanking region of several putative cis-regulatory motifs characterized in the promoters of insect immune genes: namely, Rel sites, GATA motifs, interferon consensus response elements and NF-IL6 response elements. Establishment of transgenic fly lines in which the GFP reporter gene was placed under the control of 1.5 kb of metchnikowin gene upstream sequences indicates that this fragment is able to confer full immune inducibility and tissue specificity of expression on the transgene.},
keywords = {Animals, Anti-Infective Agents, Antimicrobial Cationic Peptides, Base Sequence, Cloning, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Glycopeptides, imler, Insect, Insect Proteins, Larva, M3i, Molecular, Mutation, Peptides, Promoter Regions, Recombinant Fusion Proteins, Reporter, Restriction Mapping, Transcription},
pubstate = {published},
tppubtype = {article}
}
Metchnikowin is a recently discovered proline-rich peptide from Drosophila with antibacterial and antifungal properties. Like most other antimicrobial peptides from insects, its expression is immune-inducible. Here we present evidence that induction of metchnikowin gene expression can be mediated either by the TOLL pathway or by the imd gene product. We show that the gene remains inducible in Toll-deficient mutants, in which the antifungal response is blocked, as well as in imd mutants, which fail to mount an antibacterial response. However, in Toll-deficient;imd double mutants, metchnikowin gene expression can no longer be detected after immune challenge. Our results suggest that expression of this peptide with dual activity can be triggered by signals generated by either bacterial or fungal infection. Cloning of the metchnikowin gene revealed the presence in the 5' flanking region of several putative cis-regulatory motifs characterized in the promoters of insect immune genes: namely, Rel sites, GATA motifs, interferon consensus response elements and NF-IL6 response elements. Establishment of transgenic fly lines in which the GFP reporter gene was placed under the control of 1.5 kb of metchnikowin gene upstream sequences indicates that this fragment is able to confer full immune inducibility and tissue specificity of expression on the transgene.
1995
Lemaitre Bruno, Kromer-Metzger E, Michaut Lydia, Nicolas E, Meister Marie, Georgel Philippe, Reichhart Jean-Marc, Hoffmann Jules A
A recessive mutation, immune deficiency (imd), defines two distinct control pathways in the Drosophila host defense Article de journal
Dans: Proc. Natl. Acad. Sci. U.S.A., vol. 92, no. 21, p. 9465–9469, 1995, ISSN: 0027-8424.
Résumé | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Bacterial Infections, Base Sequence, Gene Expression Regulation, Genes, Glycopeptides, hoffmann, Insect, Insect Hormones, Insect Proteins, M3i, Male, Mutation, Mycoses, Nucleic Acid, Peptides, Protein Binding, Recessive, Regulatory Sequences, reichhart, Reporter, Survival Analysis
@article{lemaitre_recessive_1995,
title = {A recessive mutation, immune deficiency (imd), defines two distinct control pathways in the Drosophila host defense},
author = {Bruno Lemaitre and E Kromer-Metzger and Lydia Michaut and E Nicolas and Marie Meister and Philippe Georgel and Jean-Marc Reichhart and Jules A Hoffmann},
issn = {0027-8424},
year = {1995},
date = {1995-10-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {92},
number = {21},
pages = {9465--9469},
abstract = {In this paper we report a recessive mutation, immune deficiency (imd), that impairs the inducibility of all genes encoding antibacterial peptides during the immune response of Drosophila. When challenged with bacteria, flies carrying this mutation show a lower survival rate than wild-type flies. We also report that, in contrast to the antibacterial peptides, the antifungal peptide drosomycin remains inducible in a homozygous imd mutant background. These results point to the existence of two different pathways leading to the expression of two types of target genes, encoding either the antibacterial peptides or the antifungal peptide drosomycin.},
keywords = {Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Bacterial Infections, Base Sequence, Gene Expression Regulation, Genes, Glycopeptides, hoffmann, Insect, Insect Hormones, Insect Proteins, M3i, Male, Mutation, Mycoses, Nucleic Acid, Peptides, Protein Binding, Recessive, Regulatory Sequences, reichhart, Reporter, Survival Analysis},
pubstate = {published},
tppubtype = {article}
}
In this paper we report a recessive mutation, immune deficiency (imd), that impairs the inducibility of all genes encoding antibacterial peptides during the immune response of Drosophila. When challenged with bacteria, flies carrying this mutation show a lower survival rate than wild-type flies. We also report that, in contrast to the antibacterial peptides, the antifungal peptide drosomycin remains inducible in a homozygous imd mutant background. These results point to the existence of two different pathways leading to the expression of two types of target genes, encoding either the antibacterial peptides or the antifungal peptide drosomycin.
Bulet Philippe, Hegy G, Lambert J, van Dorsselaer Alan, Hoffmann Jules A, Hetru Charles
Insect immunity. The inducible antibacterial peptide diptericin carries two O-glycans necessary for biological activity Article de journal
Dans: Biochemistry, vol. 34, no. 22, p. 7394–7400, 1995, ISSN: 0006-2960.
Résumé | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Carbohydrate Sequence, Carbohydrates, Diptera, Escherichia coli, Glycopeptides, Hemolymph, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Mass Spectrometry, Plants, Trisaccharides
@article{bulet_insect_1995,
title = {Insect immunity. The inducible antibacterial peptide diptericin carries two O-glycans necessary for biological activity},
author = {Philippe Bulet and G Hegy and J Lambert and Alan van Dorsselaer and Jules A Hoffmann and Charles Hetru},
issn = {0006-2960},
year = {1995},
date = {1995-06-01},
journal = {Biochemistry},
volume = {34},
number = {22},
pages = {7394--7400},
abstract = {A bacterial challenge of larvae of the dipteran insect Phormia terranovae induces the rapid synthesis of diptericin, an antibacterial polypeptide, previously characterized at the amino acid level and indirectly by cDNA cloning studies. This 82-residue polypeptide consists of an N-terminal proline-rich domain and a central and C-terminal glycine-rich domain. Using liquid chromatography coupled to electrospray ionization-mass spectrometry, we demonstrate here that this molecule is more complex than anticipated and carries two O-substitutions on threonine residues, one in the proline-rich domain (residue 10) and one in the glycine-rich domain (residue 54). These substitutions consist of identical trisaccharides: glucose--textgreatergalactose--textgreaterN-acetylgalactosamine--textgreater(threonine). Treatment of diptericin with O-glycosidase, which selectively removes the substitutions without altering the polypeptide proper, abolishes the antibacterial activity, indicating that this posttranslational modification is essential for biological activity of the polypeptide. We also show that diptericin is posttranslationally modified by a C-terminal amidation.},
keywords = {Animals, Anti-Bacterial Agents, Carbohydrate Sequence, Carbohydrates, Diptera, Escherichia coli, Glycopeptides, Hemolymph, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Mass Spectrometry, Plants, Trisaccharides},
pubstate = {published},
tppubtype = {article}
}
A bacterial challenge of larvae of the dipteran insect Phormia terranovae induces the rapid synthesis of diptericin, an antibacterial polypeptide, previously characterized at the amino acid level and indirectly by cDNA cloning studies. This 82-residue polypeptide consists of an N-terminal proline-rich domain and a central and C-terminal glycine-rich domain. Using liquid chromatography coupled to electrospray ionization-mass spectrometry, we demonstrate here that this molecule is more complex than anticipated and carries two O-substitutions on threonine residues, one in the proline-rich domain (residue 10) and one in the glycine-rich domain (residue 54). These substitutions consist of identical trisaccharides: glucose--textgreatergalactose--textgreaterN-acetylgalactosamine--textgreater(threonine). Treatment of diptericin with O-glycosidase, which selectively removes the substitutions without altering the polypeptide proper, abolishes the antibacterial activity, indicating that this posttranslational modification is essential for biological activity of the polypeptide. We also show that diptericin is posttranslationally modified by a C-terminal amidation.
1993
Bulet Philippe, Dimarcq Jean-Luc, Hetru Charles, Lagueux Marie, Charlet Maurice, Hegy G, Dorsselaer Alan Van, Hoffmann Jules A
A novel inducible antibacterial peptide of Drosophila carries an O-glycosylated substitution Article de journal
Dans: J. Biol. Chem., vol. 268, no. 20, p. 14893–14897, 1993, ISSN: 0021-9258.
Résumé | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Base Sequence, Carbohydrates, Cloning, DNA, Escherichia coli, Gas Chromatography-Mass Spectrometry, Glycopeptides, Glycosylation, hoffmann, M3i, Molecular
@article{bulet_novel_1993,
title = {A novel inducible antibacterial peptide of Drosophila carries an O-glycosylated substitution},
author = {Philippe Bulet and Jean-Luc Dimarcq and Charles Hetru and Marie Lagueux and Maurice Charlet and G Hegy and Alan Van Dorsselaer and Jules A Hoffmann},
issn = {0021-9258},
year = {1993},
date = {1993-07-01},
journal = {J. Biol. Chem.},
volume = {268},
number = {20},
pages = {14893--14897},
abstract = {One of the facets of the host defense of higher insects is the rapid and transient synthesis, following bacterial challenge or trauma, of a battery of potent antibacterial peptides (Steiner, H., Hultmark, D., Engström, A., Bennich, H., and Boman, H. G. (1981) Nature 292, 246-248). The best characterized of these peptides are the cecropins (ibid.), 4-kDa peptides devoid of cysteines, and the insect defensins (Hoffmann, J. A., and Hetru, C. (1992) Immunol. Today 13, 411-415), 4-kDa peptides with three intramolecular disulfide bridges. Several other inducible antibacterial peptides have been characterized only at the level of their amino acid sequences (Hoffmann, J. A., Dimarcq, J. L., and Bulet, P. (1992) Médecine & Sciences 8, 432-439). We report here the isolation of a novel 19-residue proline-rich inducible antibacterial peptide from Drosophila. In contrast to all previous reports on antibacterial peptides, this molecule carries a substitution as evidenced by molecular mass determinations; our data show that this reflects the O-glycosylation of a Thr residue by an N-acetylgalactosamine plus a galactose. A synthetic nonsubstituted peptide of identical amino acid sequence has an activity several times lower (5-10) than the native compound. Our data suggest that this substitution represents a post-translational modification essential for the full biological activity of this novel peptide.},
keywords = {Animals, Anti-Bacterial Agents, Base Sequence, Carbohydrates, Cloning, DNA, Escherichia coli, Gas Chromatography-Mass Spectrometry, Glycopeptides, Glycosylation, hoffmann, M3i, Molecular},
pubstate = {published},
tppubtype = {article}
}
One of the facets of the host defense of higher insects is the rapid and transient synthesis, following bacterial challenge or trauma, of a battery of potent antibacterial peptides (Steiner, H., Hultmark, D., Engström, A., Bennich, H., and Boman, H. G. (1981) Nature 292, 246-248). The best characterized of these peptides are the cecropins (ibid.), 4-kDa peptides devoid of cysteines, and the insect defensins (Hoffmann, J. A., and Hetru, C. (1992) Immunol. Today 13, 411-415), 4-kDa peptides with three intramolecular disulfide bridges. Several other inducible antibacterial peptides have been characterized only at the level of their amino acid sequences (Hoffmann, J. A., Dimarcq, J. L., and Bulet, P. (1992) Médecine & Sciences 8, 432-439). We report here the isolation of a novel 19-residue proline-rich inducible antibacterial peptide from Drosophila. In contrast to all previous reports on antibacterial peptides, this molecule carries a substitution as evidenced by molecular mass determinations; our data show that this reflects the O-glycosylation of a Thr residue by an N-acetylgalactosamine plus a galactose. A synthetic nonsubstituted peptide of identical amino acid sequence has an activity several times lower (5-10) than the native compound. Our data suggest that this substitution represents a post-translational modification essential for the full biological activity of this novel peptide.