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Montagnani C, Kappler C, Reichhart JM, Escoubas JM. Cg-Rel, the first Rel/NF-kappaB homolog characterized in a mollusk, the Pacific oyster Crassostrea gigas. FEBS Lett 2004; 561:75-82. [PMID: 15013754 DOI: 10.1016/s0014-5793(04)00124-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2003] [Accepted: 12/30/2003] [Indexed: 11/24/2022]
Abstract
We report here the identification and functional characterization of Cg-Rel, a gene encoding the Crassostrea gigas homolog of Rel/NF-kappaB transcription factors found in insects and mammals. Sequence and phylogenetic analysis showed that Cg-Rel shares the structural organization of Rel/NF-kappaB transcription factors of class II. It includes a Rel homology domain as well as a C-terminal transactivation domain (TD). Overexpression of Cg-Rel in the Drosophila S2 cell line activated the expression of a NF-kappaB-dependent reporter gene, whereas transfection with a Cg-Rel construct containing a C-terminal deletion of the TD or using a reporter gene with mutated kappaB binding sites failed to activate expression. These results suggest that Cg-Rel is a functional member of the Rel family of transcription factors, making this the sixth structurally homologous component of the Rel/NF-kappaB pathway characterized in C. gigas. Based on homology to other invertebrates' Rel/NF-kappaB cascade, the function of the oyster pathway may serve to regulate genes involved in innate defense and/or development. These findings serve to highlight a potentially important regulatory pathway to the study of oyster immunology, hence allowing comparison of the immune system in vertebrates and invertebrates, an important key issue to understand its evolution.
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Affiliation(s)
- C Montagnani
- Laboratoire de Défense et Résistance chez les Invertébrés Marins (DRIM) (IFREMER, CNRS, UMII), Université de Montpellier II, 2 place Eugène Bataillon, CC80, 34095 Montpellier, France
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Irving P, Troxler L, Heuer TS, Belvin M, Kopczynski C, Reichhart JM, Hoffmann JA, Hetru C. A genome-wide analysis of immune responses in Drosophila. Proc Natl Acad Sci U S A 2001; 98:15119-24. [PMID: 11742098 PMCID: PMC64993 DOI: 10.1073/pnas.261573998] [Citation(s) in RCA: 300] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Oligonucleotide DNA microarrays were used for a genome-wide analysis of immune-challenged Drosophila infected with Gram-positive or Gram-negative bacteria, or with fungi. Aside from the expression of an established set of immune defense genes, a significant number of previously unseen immune-induced genes were found. Genes of particular interest include corin- and Stubble-like genes, both of which have a type II transmembrane domain; easter- and snake-like genes, which may fulfil the roles of easter and snake in the Toll pathway; and a masquerade-like gene, potentially involved in enzyme regulation. The microarray data has also helped to greatly reduce the number of target genes in large gene groups, such as the proteases, helping to direct the choices for future mutant studies. Many of the up-regulated genes fit into the current conceptual framework of host defense, whereas others, including the substantial number of genes with unknown functions, offer new avenues for research.
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Affiliation(s)
- P Irving
- Institut de Biologie Moléculaire et Cellulaire, Unité Propre de Recherche, 9022 du Centre National de la Recherche Scientifique, 15 Rue Descartes, F67084 Strasbourg Cedex, France
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Michel T, Reichhart JM, Hoffmann JA, Royet J. Drosophila Toll is activated by Gram-positive bacteria through a circulating peptidoglycan recognition protein. Nature 2001; 414:756-9. [PMID: 11742401 DOI: 10.1038/414756a] [Citation(s) in RCA: 554] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microbial infection activates two distinct intracellular signalling cascades in the immune-responsive fat body of Drosophila. Gram-positive bacteria and fungi predominantly induce the Toll signalling pathway, whereas Gram-negative bacteria activate the Imd pathway. Loss-of-function mutants in either pathway reduce the resistance to corresponding infections. Genetic screens have identified a range of genes involved in these intracellular signalling cascades, but how they are activated by microbial infection is largely unknown. Activation of the transmembrane receptor Toll requires a proteolytically cleaved form of an extracellular cytokine-like polypeptide, Spätzle, suggesting that Toll does not itself function as a bona fide recognition receptor of microbial patterns. This is in apparent contrast with the mammalian Toll-like receptors and raises the question of which host molecules actually recognize microbial patterns to activate Toll through Spätzle. Here we present a mutation that blocks Toll activation by Gram-positive bacteria and significantly decreases resistance to this type of infection. The mutation semmelweis (seml) inactivates the gene encoding a peptidoglycan recognition protein (PGRP-SA). Interestingly, seml does not affect Toll activation by fungal infection, indicating the existence of a distinct recognition system for fungi to activate the Toll pathway.
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Affiliation(s)
- T Michel
- Institut de Biologie Moleculaire et Cellulaire, UPR 9022 du CNRS, 15 rue Rene Descartes, 67084 Strasbourg Cedex, France
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Georgel P, Naitza S, Kappler C, Ferrandon D, Zachary D, Swimmer C, Kopczynski C, Duyk G, Reichhart JM, Hoffmann JA. Drosophila immune deficiency (IMD) is a death domain protein that activates antibacterial defense and can promote apoptosis. Dev Cell 2001; 1:503-14. [PMID: 11703941 DOI: 10.1016/s1534-5807(01)00059-4] [Citation(s) in RCA: 324] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We report the molecular characterization of the immune deficiency (imd) gene, which controls antibacterial defense in Drosophila. imd encodes a protein with a death domain similar to that of mammalian RIP (receptor interacting protein), a protein that plays a role in both NF-kappaB activation and apoptosis. We show that imd functions upstream of the DmIKK signalosome and the caspase DREDD in the control of antibacterial peptide genes. Strikingly, overexpression of imd leads to constitutive transcription of these genes and to apoptosis, and both effects are blocked by coexpression of the caspase inhibitor P35. We also show that imd is involved in the apoptotic response to UV irradiation. These data raise the possibility that antibacterial response and apoptosis share common control elements in Drosophila.
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Affiliation(s)
- P Georgel
- Institut de Biologie Moleculaire et Cellulaire, UPR 9022 du CNRS, Strasbourg, France
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Green C, Levashina E, McKimmie C, Dafforn T, Reichhart JM, Gubb D. The necrotic gene in Drosophila corresponds to one of a cluster of three serpin transcripts mapping at 43A1.2. Genetics 2000; 156:1117-27. [PMID: 11063688 PMCID: PMC1461326 DOI: 10.1093/genetics/156.3.1117] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutants of the necrotic (nec) gene in Drosophila melanogaster die in the late pupal stage as pharate adults, or hatch as weak, but relatively normal-looking, flies. Adults develop black melanized spots on the body and leg joints, the abdomen swells with hemolymph, and flies die within 3 or 4 days of eclosion. The TOLL-mediated immune response to fungal infections is constitutively activated in nec mutants and pleiotropic phenotypes include melanization and cellular necrosis. These changes are consistent with activation of one or more proteolytic cascades. The nec gene corresponds to Spn43Ac, one of a cluster of three putative serine proteinase inhibitors at 43A1.2, on the right arm of chromosome 2. Although serpins have been implicated in the activation of many diverse pathways, lack of an individual serpin rarely causes a detectable phenotype. Absence of Spn43Ac, however, gives a clear phenotype, which will allow a mutational analysis of critical features of the molecular structure of serpins.
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Affiliation(s)
- C Green
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, England
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Tzou P, Ohresser S, Ferrandon D, Capovilla M, Reichhart JM, Lemaitre B, Hoffmann JA, Imler JL. Tissue-specific inducible expression of antimicrobial peptide genes in Drosophila surface epithelia. Immunity 2000; 13:737-48. [PMID: 11114385 DOI: 10.1016/s1074-7613(00)00072-8] [Citation(s) in RCA: 415] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The production of antimicrobial peptides is an important aspect of host defense in multicellular organisms. In Drosophila, seven antimicrobial peptides with different spectra of activities are synthesized by the fat body during the immune response and secreted into the hemolymph. Using GFP reporter transgenes, we show here that all seven Drosophila antimicrobial peptides can be induced in surface epithelia in a tissue-specific manner. The imd gene plays a critical role in the activation of this local response to infection. In particular, drosomycin expression, which is regulated by the Toll pathway during the systemic response, is regulated by imd in the respiratory tract, thus demonstrating the existence of distinct regulatory mechanisms for local and systemic induction of antimicrobial peptide genes in Drosophila.
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Affiliation(s)
- P Tzou
- Centre de Génétique Moléculaire du CNRS, 91198 Gif-sur-Yvette, France
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Rutschmann S, Jung AC, Hetru C, Reichhart JM, Hoffmann JA, Ferrandon D. The Rel protein DIF mediates the antifungal but not the antibacterial host defense in Drosophila. Immunity 2000; 12:569-80. [PMID: 10843389 DOI: 10.1016/s1074-7613(00)80208-3] [Citation(s) in RCA: 269] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We have isolated two Drosophila lines that carry point mutations in the gene coding for the NF-KB-like factor DIF. Like mutants of the Toll pathway, Dif mutant flies are susceptible to fungal but not to bacterial infections. Genetic epistasis experiments demonstrate that Dif mediates the Toll-dependent control of the inducibility of the antifungal peptide gene Drosomycin. Strikingly, DIF alone is required for the antifungal response in adults, but is redundant in larvae with Dorsal, another Rel family member. In Drosophila, Dif appears to be dedicated to the antifungal defense elicited by fungi and gram-positive bacteria. We discuss in this light the possibility that NF-KB1/p50 might be required more specifically in the innate immune response against gram-positive bacteria in mammals.
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Affiliation(s)
- S Rutschmann
- Institut de Biologie Moléculaire et Cellulaire, UPR 9022 du CNRS, Strasbourg, France
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Levashina EA, Langley E, Green C, Gubb D, Ashburner M, Hoffmann JA, Reichhart JM. Constitutive activation of toll-mediated antifungal defense in serpin-deficient Drosophila. Science 1999; 285:1917-9. [PMID: 10489372 DOI: 10.1126/science.285.5435.1917] [Citation(s) in RCA: 325] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The antifungal defense of Drosophila is controlled by the spaetzle/Toll/cactus gene cassette. Here, a loss-of-function mutation in the gene encoding a blood serine protease inhibitor, Spn43Ac, was shown to lead to constitutive expression of the antifungal peptide drosomycin, and this effect was mediated by the spaetzle and Toll gene products. Spaetzle was cleaved by proteolytic enzymes to its active ligand form shortly after immune challenge, and cleaved Spaetzle was constitutively present in Spn43Ac-deficient flies. Hence, Spn43Ac negatively regulates the Toll signaling pathway, and Toll does not function as a pattern recognition receptor in the Drosophila host defense.
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Affiliation(s)
- E A Levashina
- UPR 9022 CNRS, Institut de Biologie Moléculaire et Cellulaire, 15 Rue René Descartes, Strasbourg 67084, France
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Manfruelli P, Reichhart JM, Steward R, Hoffmann JA, Lemaitre B. A mosaic analysis in Drosophila fat body cells of the control of antimicrobial peptide genes by the Rel proteins Dorsal and DIF. EMBO J 1999; 18:3380-91. [PMID: 10369678 PMCID: PMC1171418 DOI: 10.1093/emboj/18.12.3380] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Expression of the gene encoding the antifungal peptide Drosomycin in Drosophila adults is controlled by the Toll signaling pathway. The Rel proteins Dorsal and DIF (Dorsal-related immunity factor) are possible candidates for the transactivating protein in the Toll pathway that directly regulates the drosomycin gene. We have examined the requirement of Dorsal and DIF for drosomycin expression in larval fat body cells, the predominant immune-responsive tissue, using the yeast site-specific flp/FRT recombination system to generate cell clones homozygous for a deficiency uncovering both the dorsal and the dif genes. Here we show that in the absence of both genes, the immune-inducibility of drosomycin is lost but can be rescued by overexpression of either dorsal or dif under the control of a heat-shock promoter. This result suggests a functional redundancy between both Rel proteins in the control of drosomycin gene expression in the larvae of Drosophila. Interestingly, the gene encoding the antibacterial peptide Diptericin remains fully inducible in the absence of the dorsal and dif genes. Finally, we have used fat body cell clones homozygous for various mutations to show that a linear activation cascade Spaetzle--> Toll-->Cactus-->Dorsal/DIF leads to the induction of the drosomycin gene in larval fat body cells.
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Affiliation(s)
- P Manfruelli
- Institut de Biologie Moléculaire et Cellulaire, UPR 9022 du Centre National de la Recherche Scientifique, 15, Rue René Descartes, F-67084 Strasbourg Cedex, France
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Gross I, Georgel P, Oertel-Buchheit P, Schnarr M, Reichhart JM. Dorsal-B, a splice variant of the Drosophila factor Dorsal, is a novel Rel/NF-kappaB transcriptional activator. Gene 1999; 228:233-42. [PMID: 10072776 DOI: 10.1016/s0378-1119(98)00595-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The Drosophila transcription factor Dorsal, a member of the Rel/NF-kappaB family of proteins, plays a key role in the establishment of dorsoventral polarity in the early embryo and is also involved in the immune response. Here, we present evidence that the primary transcript of dorsal can be alternatively spliced, generating Dorsal-B, a new Rel/NF-kappaB family member. Dorsal and Dorsal-B are identical in the N-terminal region, which comprises both a DNA-binding domain and a dimerization domain. However, Dorsal-B lacks the nuclear localization signal located at the end of the Rel domain of Dorsal and is totally divergent in the C-terminal portion. Although Dorsal-B by itself is not able to induce the expression of a kappaB-controlled Luciferase reporter gene, we demonstrate that its C-terminal portion has transactivating properties. Analysis of the dorsal-B expression pattern indicates that the splicing is tissue-specific and excludes a putative role in early embryogenesis. However, dorsal-B synthesis is enhanced upon septic injury, and this challenge induces a nuclear accumulation of the protein in fat body cells suggesting that it may be involved in the immune response.
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Affiliation(s)
- I Gross
- UPR CNRS 9022, Réponse Immunitaire et Développement chez les Insectes, Institut de Biologie Moléculaire et Cellulaire, 15 rue René Descartes, 67084, Strasbourg Cedex, France
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Nicolas E, Reichhart JM, Hoffmann JA, Lemaitre B. In vivo regulation of the IkappaB homologue cactus during the immune response of Drosophila. J Biol Chem 1998; 273:10463-9. [PMID: 9553105 DOI: 10.1074/jbc.273.17.10463] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The dorsoventral regulatory gene pathway (spätzle/Toll/cactus) controls the expression of several antimicrobial genes during the immune response of Drosophila. This regulatory cascade shows striking similarities with the cytokine-induced activation cascade of NF-kappaB during the inflammatory response in mammals. Here, we have studied the regulation of the IkappaB homologue Cactus in the fat body during the immune response. We observe that the cactus gene is up-regulated in response to immune challenge. Interestingly, the expression of the cactus gene is controlled by the spätzle/Toll/cactus gene pathway, indicating that the cactus gene is autoregulated. We also show that two Cactus isoforms are expressed in the cytoplasm of fat body cells and that they are rapidly degraded and resynthesized after immune challenge. This degradation is also dependent on the Toll signaling pathway. Altogether, our results underline the striking similarities between the regulation of IkappaB and cactus during the immune response.
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Affiliation(s)
- E Nicolas
- Institut de Biologie Moléculaire et Cellulaire, UPR 9022 du CNRS, 15 rue René Descartes, 67084 Strasbourg Cedex, France
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Lemaitre B, Reichhart JM, Hoffmann JA. Drosophila host defense: differential induction of antimicrobial peptide genes after infection by various classes of microorganisms. Proc Natl Acad Sci U S A 1997; 94:14614-9. [PMID: 9405661 PMCID: PMC25070 DOI: 10.1073/pnas.94.26.14614] [Citation(s) in RCA: 712] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Insects respond to microbial infection by the rapid and transient expression of several genes encoding potent antimicrobial peptides. Herein we demonstrate that this antimicrobial response of Drosophila is not aspecific but can discriminate between various classes of microorganisms. We first observe that the genes encoding antibacterial and antifungal peptides are differentially expressed after injection of distinct microorganisms. More strikingly, Drosophila that are naturally infected by entomopathogenic fungi exhibit an adapted response by producing only peptides with antifungal activities. This response is mediated through the selective activation of the Toll pathway.
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Affiliation(s)
- B Lemaitre
- Institut de Biologie Moléculaire et Cellulaire, Unité Propre de Recherche 9022 du Centre National de la Recherche Scientifique, 15 rue René Descartes, 67084 Strasbourg Cedex, France
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Charlet M, Lagueux M, Reichhart JM, Hoffmann D, Braun A, Meister M. Cloning of the gene encoding the antibacterial peptide drosocin involved in Drosophila immunity. Expression studies during the immune response. Eur J Biochem 1996; 241:699-706. [PMID: 8944755 DOI: 10.1111/j.1432-1033.1996.00699.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A potent inducible antibacterial peptide carrying an O-glycosylated substitution has recently been isolated from Drosophila [Bulet, P., Dimarcq, J. L., Hetru, C., Lagueux, M., Charlet, M., Hegy, G., Van Dorsselaer, A. and Hoffmann, J. A. (1993) J. Biol. Chem. 268, 14893-14897]. Here we report cloning studies that show that Drosophila contains a single, intronless gene, located at position 51C1-6, which encodes the precursor protein from which drosocin is processed. The upstream and the downstream sequences of the drosocin gene contain putative cis-regulatory elements similar to mammalian regulatory motifs, namely three kappa B-related decameric sequences. The drosocin gene is silent in naive animals, and is strongly induced with acute phase kinetics after immune challenge in larvae and in adults. We have established several transgenic fly lines in which reporter genes were placed under the control of various drosocin promoter sequences. Our results indicate that 2.5 kb of upstream sequences confer inducibility and tissue specificity to the transgene, but that the level of its expression in the fat body after immune challenge is low. Addition of genomic regions downstream of the drosocin transcribed sequences results in increased transcription levels, which are similar for the fusion and the resident drosocin genes upon infection. Analysis of transgenic fly lines showed that the drosocin reporter gene is constitutively expressed in the oviducts of egg-laying females.
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Affiliation(s)
- M Charlet
- Unité Propre de Recherche 9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
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Michaut L, Fehlbaum P, Moniatte M, Van Dorsselaer A, Reichhart JM, Bulet P. Determination of the disulfide array of the first inducible antifungal peptide from insects: drosomycin from Drosophila melanogaster. FEBS Lett 1996; 395:6-10. [PMID: 8849679 DOI: 10.1016/0014-5793(96)00992-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Drosomycin is a 44-residue antifungal peptide with four intramolecular disulfide bridges which have been isolated from immune-challenged Drosophila. To produce adequate amounts of this peptide for 3D-structure analysis, studies on the mode of action and activity spectrum, we expressed a synthetic cDNA in Saccharomyces cerevisiae. For this purpose, we used the mating factor alpha gene and concomitantly overexpressed the KEX2 gene to increase the yield of fully processed drosomycin. Using a combination of Edman degradation and mass spectrometry, we show that drosomycin shares the same array of intramolecular disulfide bridges than plant defensins, in addition to their sequence similarities.
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Affiliation(s)
- L Michaut
- Institut de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Réponse Immunitaire et Développement chezles Insectes, Strasbourg, France
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Lemaitre B, Nicolas E, Michaut L, Reichhart JM, Hoffmann JA. The dorsoventral regulatory gene cassette spätzle/Toll/cactus controls the potent antifungal response in Drosophila adults. Cell 1996; 86:973-83. [PMID: 8808632 DOI: 10.1016/s0092-8674(00)80172-5] [Citation(s) in RCA: 2519] [Impact Index Per Article: 90.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The cytokine-induced activation cascade of NF-kappaB in mammals and the activation of the morphogen dorsal in Drosophila embryos show striking structural and functional similarities (Toll/IL-1, Cactus/I-kappaB, and dorsal/NF-kappaB). Here we demonstrate that these parallels extend to the immune response of Drosophila. In particular, the intracellular components of the dorsoventral signaling pathway (except for dorsal) and the extracellular Toll ligand, spätzle, control expression of the antifungal peptide gene drosomycin in adults. We also show that mutations in the Toll signaling pathway dramatically reduce survival after fungal infection. Antibacterial genes are induced either by a distinct pathway involving the immune deficiency gene (imd) or by combined activation of both imd and dorsoventral pathways.
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Affiliation(s)
- B Lemaitre
- Institut de Biologie Moléculaire at Cellulaire, UPR 9022 du Centre National de la Recherche Scientifique, Strasbourg, France
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Gross I, Georgel P, Kappler C, Reichhart JM, Hoffmann JA. Drosophila immunity: a comparative analysis of the Rel proteins dorsal and Dif in the induction of the genes encoding diptericin and cecropin. Nucleic Acids Res 1996; 24:1238-45. [PMID: 8614625 PMCID: PMC145794 DOI: 10.1093/nar/24.7.1238] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In Drosophila, bacterial challenge induces the rapid transcription of several genes encoding potent antibacterial peptides. The upstream sequences of the diptericin and cecropin Al genes, which have been investigated in detail, contain two, respectively one sequence element homologous to the binding site of the mammalian nuclear factor kappaB. These elements have been shown to be mandatory for immune-induced transcription of both genes. Functional studies have shown that these kappaB-related elements can be the target for the Drosophila Rel proteins dorsal and Dif. Here we present a comparative analysis of the transactivating capacities of these proteins on reporter genes fused to either the diptericin or the cecropin kappaB-related motifs. We conclude from our results: (i) the kappaB motifs of the diptericin and cecropin genes are not functionally equivalent; (ii) the dorsal and Dif proteins have distinct DNA-binding characteristics; (iii) dorsal and Dif can heterodimerize in vitro; (iv) mutants containing no copies of dorsal and a single copy of Dif retain their full capacity to express the diptericin and cecropin genes in response to challenge.
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Affiliation(s)
- I Gross
- Institut de Biologie Moléculaire et Cellulaire, CNRS, Strasbourg, France
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Abstract
The hallmark of the innate immune response of higher insects is the rapid and transient synthesis of a battery of broad spectrum antimicrobial peptides by the fat body. The control of the genes encoding these peptides involves cis-regulatory promoter elements homologous to sequences functional in mammalian acute-phase genes. Study of immune-deficient mutants of Drosophila has indicated that distinct pathways control the antibacterial and antifungal responses in this species. Novel receptors potentially involved in the initiation of the immune response have been recently characterized.
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Affiliation(s)
- J A Hoffmann
- Institut de Biologie Moléculaire et Cellulaire, CNRS, Strasbourg, France
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Levashina EA, Ohresser S, Bulet P, Reichhart JM, Hetru C, Hoffmann JA. Metchnikowin, a novel immune-inducible proline-rich peptide from Drosophila with antibacterial and antifungal properties. Eur J Biochem 1995; 233:694-700. [PMID: 7588819 DOI: 10.1111/j.1432-1033.1995.694_2.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One of the characteristics of the host defense of higher insects is the rapid and transient synthesis of a variety of potent antimicrobial peptides. To date, several distinct inducible antimicrobial peptides or peptide families have been totally or partially characterized. We present here the isolation and characterization of a novel 26-residue proline-rich immune-inducible peptide from Drosophila, which exhibits both antibacterial (Gram-positive) and antifungal activities. Peptide sequencing and cDNA cloning indicate the presense of two isoforms in our Drosophila Oregon strain, which differ by one residue (His compared to Arg) as a consequence of a single nucleotide change. The gene, which maps in position 52A1-2 on the right arm of the second chromosome, is expressed in the fat body after immune challenge. The novel peptide, which we propose to name metchnikowin, is a member of a family of proline-rich peptides, and we discuss the possible evolutionary relationships within this family.
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Affiliation(s)
- E A Levashina
- Department of Genetics and Breeding, St Petersburg State University, Russia
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Lemaitre B, Kromer-Metzger E, Michaut L, Nicolas E, Meister M, Georgel P, Reichhart JM, Hoffmann JA. A recessive mutation, immune deficiency (imd), defines two distinct control pathways in the Drosophila host defense. Proc Natl Acad Sci U S A 1995; 92:9465-9. [PMID: 7568155 PMCID: PMC40822 DOI: 10.1073/pnas.92.21.9465] [Citation(s) in RCA: 442] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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.
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Affiliation(s)
- B Lemaitre
- Institut de Biologie Moléculaire et Cellulaire, Unité Propre de Recherche 9022 du Centre National de la Recherche Scientifique, Strasbourg, France
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22
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Georgel P, Kappler C, Langley E, Gross I, Nicolas E, Reichhart JM, Hoffmann JA. Drosophila immunity. A sequence homologous to mammalian interferon consensus response element enhances the activity of the diptericin promoter. Nucleic Acids Res 1995; 23:1140-5. [PMID: 7537872 PMCID: PMC306822 DOI: 10.1093/nar/23.7.1140] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Bacterial challenge of larvae or adults of Drosophila induces the rapid transcription of several genes encoding antibacterial peptides with a large spectrum of activity. One of these peptides, the 82-residue anti-gram negative diptericin, is encoded by a single intronless gene and we are investigating the control of expression of this gene. Previous studies using both transgenic experiments and footprint analysis have highlighted the role in the induction of this gene of a 30 nucleotide region which contains three partially overlapping motifs with sequence homology to mammalian NF-kappa B and NF-IL6 response elements and to the GAAANN sequence present in the interferon consensus response elements of some mammalian interferon-induced genes. We now show that the latter sequence binds in immune responsive tissues (fat body, blood cells) of Drosophila a approximately 45 kDa polypeptide which cross-reacts with a polyserum directed against mammalian interferon Regulatory Factor-I. Using a transfection assay of Drosophila tumorous blood cells, we show that the GAAANN sequence positively regulates the activity of the diptericin promoter. We propose that this motif cooperatively interacts with the other response elements in the regulation of the diptericin gene expression.
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Affiliation(s)
- P Georgel
- Institut de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Strasbourg, France
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23
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Lemaitre B, Meister M, Govind S, Georgel P, Steward R, Reichhart JM, Hoffmann JA. Functional analysis and regulation of nuclear import of dorsal during the immune response in Drosophila. EMBO J 1995; 14:536-45. [PMID: 7859742 PMCID: PMC398111 DOI: 10.1002/j.1460-2075.1995.tb07029.x] [Citation(s) in RCA: 184] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In addition to its function in embryonic development, the NF-kappa B/rel-related gene dorsal (dl) of Drosophila is expressed in larval and adult fat body where its RNA expression is enhanced upon injury. Injury also leads to a rapid nuclear translocation of dl from the cytoplasm in fat body cells. Here we present data which strongly suggest that the nuclear localization of dl during the immune response is controlled by the Toll signaling pathway, comprising gene products that participate in the intracellular part of the embryonic dorsoventral pathway. We also report that in mutants such as Toll or cactus, which exhibit melanotic tumor phenotypes, dl is constitutively nuclear. Together, these results point to a potential link between the Toll signaling pathway and melanotic tumor induction. Although dl has been shown previously to bind to kappa B-related motifs within the promoter of the antibacterial peptide coding gene diptericin, we find that injury-induced expression of diptericin can occur in the absence of dl. Furthermore, the melanotic tumor phenotype of Toll and cactus is not dl dependent. These data underline the complexity of the Drosophila immune response. Finally, we observed that like other rel proteins, dl can control the level of its own transcription.
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Affiliation(s)
- B Lemaitre
- Institut de Biologie Moléculaire et Cellulaire, UPR 9022 du CNRS, Strasbourg, France
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24
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Meister M, Braun A, Kappler C, Reichhart JM, Hoffmann JA. Insect immunity. A transgenic analysis in Drosophila defines several functional domains in the diptericin promoter. EMBO J 1994; 13:5958-66. [PMID: 7813433 PMCID: PMC395571 DOI: 10.1002/j.1460-2075.1994.tb06941.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Diptericins are antibacterial polypeptides which are strongly induced in the fat body and blood cells of dipteran insects in response to septic injury. The promoter of the single-copy, intronless diptericin gene of Drosophila contains several nucleotide sequences homologous to mammalian cis-regulatory motifs involved in the control of acute phase response genes. Extending our previous studies on the expression of the diptericin gene, we now report a quantitative analysis of the contribution of various putative regulatory elements to the bacterial inducibility of this gene, based on the generation of 60 transgenic fly lines carrying different elements fused to a reporter gene. Our data definitively identify two Kappa B-related motifs in the proximal promoter as the sites conferring inducibility and tissue-specific expression to the diptericin gene. These motifs alone, however, mediate only minimal levels of expression. Additional proximal regulatory elements are necessary to attain some 20% of the full response and we suspect a role for sequences homologous to mammalian IL6 response elements and interferon-gamma responsive sites in this up-regulation. The transgenic experiments also reveal the existence of a distal regulatory element located upstream of -0.6 kb which increases the level of expression by a factor of five.
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Affiliation(s)
- M Meister
- Institut de Biologie Moléculaire et Cellulaire, UPR 9022 du CNRS, Strasbourgh, France
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25
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Dimarcq JL, Hoffmann D, Meister M, Bulet P, Lanot R, Reichhart JM, Hoffmann JA. Characterization and transcriptional profiles of a Drosophila gene encoding an insect defensin. A study in insect immunity. Eur J Biochem 1994; 221:201-9. [PMID: 8168509 DOI: 10.1111/j.1432-1033.1994.tb18730.x] [Citation(s) in RCA: 144] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Insect defensins are a family of 4-kDa, cationic, inducible antibacterial peptides which bear six cysteine residues engaged in three intramolecular disulfide bridges. They owe their name to certain sequence similarities with defensins from mammalian neutrophiles and macrophages. We report the characterization of a novel defensin isoform from Drosophila and the cloning of the gene encoding a preprodefensin. The gene, which is intronless and present in a single copy/haploid genome, maps at position 46CD on the right arm of the second chromosome. The analysis of the upstream region of the gene reveals the presence of multiple putative cis-regulatory sequences similar to mammalian regulatory motifs of acute-phase-response genes. Transcriptional profiles indicate that the Drosophila defensin gene is induced by bacterial challenge with acute-phase kinetics. It is also expressed in the absence of immune challenge during metamorphosis. These and other data on the Drosophila defensin gene lead us to suggest that insect and mammalian defensins have evolved independently.
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Affiliation(s)
- J L Dimarcq
- UPR CNRS Réponse immunitair et Développement chez les Insectes, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
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26
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Georgel P, Meister M, Kappler C, Lemaitre B, Reichhart JM, Hoffmann JA. Insect immunity: the diptericin promoter contains multiple functional regulatory sequences homologous to mammalian acute-phase response elements. Biochem Biophys Res Commun 1993; 197:508-17. [PMID: 7505569 DOI: 10.1006/bbrc.1993.2508] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We are using the diptericin gene as a model system to study the control of expression of the genes encoding antibacterial peptides during the Drosophila immune reaction. In order to investigate the putative regulatory regions in the diptericin promoter, we performed DNaseI footprinting experiments combined with gel-shift assays in two inducible systems: the larval fat body and a tumorous Drosophila blood cell line. Our results confirm the importance of kappa B-like elements previously described in the immune response of insects and reveal for the first time the involvement of other regions containing sequences homologous to mammalian acute-phase response elements.
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Affiliation(s)
- P Georgel
- Laboratoire de Biologie Générale, Bases Cellulaires et Moléculaires de la Réponse Immunitaire des Insectes, UA CNRS 1490, Strasbourg, France
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27
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Reichhart JM, Georgel P, Meister M, Lemaitre B, Kappler C, Hoffmann JA. Expression and nuclear translocation of the rel/NF-kappa B-related morphogen dorsal during the immune response of Drosophila. C R Acad Sci III 1993; 316:1218-24. [PMID: 8062131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The rel/NF-kappa B-related morphogen dorsal is a maternally expressed gene which is involved in the control of the dorso-ventral axis during early embryogenesis of Drosophila. We show that this gene is also expressed in the fat body of larvae and adults of Drosophila as well as in a tumorous blood cell line: its expression is noticeably enhanced upon bacterial (or lipopolysaccharide) challenge. This challenge also induces within 15-30 min a nuclear translocation of the dorsal protein. The genes encoding inducible antibacterial peptides in Drosophila contain kappa B-related nucleotide sequences and we show that the dorsal protein can bind to such motifs and sequence-specifically transactivate a reporter gene in co-transfection experiments with a Drosophila cell line. However, in dl1 mutants, in the absence of dorsal protein, the genes encoding antibacterial peptides retain their inducibility, suggesting a multifactorial control. The results indicate that in addition to its role in embryogenesis, dorsal is involved in the immune response of Drosophila. They also strengthen the analogy between the mammalian acute phase response and the insect immune response.
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Affiliation(s)
- J M Reichhart
- Laboratoire de Biologie Générale de l'Université Louis-Pasteur, UA CNRS 1490, Strasbourg, France
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28
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Abstract
Drosophila, like other insects, responds to the injection of bacteria by the rapid and transient synthesis of a battery of potent antibacterial peptides. Only a few of these peptides have been fully characterized to date. We review our recent data on the control of the expression of a gene encoding one of the induced peptides, i.e. diptericin. Our data highlight the role of proximal cis-regulatory motifs similar to regulatory elements binding NF-kappa B and NF-IL6 in promoters of some immune genes of mammals. We argue that the Drosophila host defense is homologous to the mammalian acute phase response.
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Affiliation(s)
- J A Hoffmann
- Laboratoire de Biologie Générale, Université Louis Pasteur, URA 1490 du CNRS, Strasbourg, France
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29
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Kappler C, Meister M, Lagueux M, Gateff E, Hoffmann JA, Reichhart JM. Insect immunity. Two 17 bp repeats nesting a kappa B-related sequence confer inducibility to the diptericin gene and bind a polypeptide in bacteria-challenged Drosophila. EMBO J 1993; 12:1561-8. [PMID: 8467806 PMCID: PMC413369 DOI: 10.1002/j.1460-2075.1993.tb05800.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The Drosophila diptericin gene codes for a 9 kDa antibacterial peptide and is rapidly and transiently expressed in larvae and adults after bacterial challenge. It is also induced in a tumorous Drosophila blood cell line by the addition of lipopolysaccharide (LPS). The promoter of this gene contains two 17 bp repeats located closely upstream of the TATA-box and harbouring a decameric kappa B-related sequence. This study reports that the replacement of the two 17 bp repeats by random sequences abolishes bacteria inducibility in transgenic fly lines. In transfected tumorous blood cells, the replacement of both or either of the 17 bp motifs reduces dramatically LPS inducibility, whereas multiple copies significantly increase the level of transcriptional activation by LPS challenge. A specific DNA-protein binding activity is evidenced in cytoplasmic and nuclear extracts of induced blood cells and fat body. It is absent in controls. It is proposed that induction of the diptericin gene mediated by the two 17 bp repeats occurs via a mechanism similar to that of mammalian NF-kappa B.
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Affiliation(s)
- C Kappler
- Laboratoire de Biologie Générale, Université Louis Pasteur, Strasbourg, France
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30
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Reichhart JM, Meister M, Dimarcq JL, Zachary D, Hoffmann D, Ruiz C, Richards G, Hoffmann JA. Insect immunity: developmental and inducible activity of the Drosophila diptericin promoter. EMBO J 1992; 11:1469-77. [PMID: 1373375 PMCID: PMC556595 DOI: 10.1002/j.1460-2075.1992.tb05191.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Diptericins are 9 kDa inducible antibacterial peptides initially isolated from immune haemolymph of Phormia (Diptera). Following the isolation of a Drosophila cDNA encoding a diptericin homologue, we have now cloned a genomic fragment containing the Drosophila diptericin gene. To dissect the regulation of this gene, we have transformed flies with a fusion gene in which the reporter beta-galactosidase gene is under the control of 2.2 kb upstream sequences of the diptericin gene. We show that such a fusion gene is inducible by injection of live bacteria or complete Freund's adjuvant and respects the tissue specific expression pattern of the resident diptericin gene. Our analysis reveals at least four distinct phases in the regulation of this gene: young larvae, late third instar larvae, pupae and adults. This complexity may be related to the presence in the upstream sequences of multiple copies of response elements previously characterized in genes encoding acute phase response proteins in mammals (e.g. NK-kappa B, NF-kappa B related, NF-IL6 response elements).
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Affiliation(s)
- J M Reichhart
- Laboratoire de Biologie Générale, Université Louis Pasteur, Unité Associée au CNRS no. 672 Endocrinologie et Immunologie des Insectes, Strasbourg, France
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31
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Bulet P, Cociancich S, Dimarcq JL, Lambert J, Reichhart JM, Hoffmann D, Hetru C, Hoffmann JA. Insect immunity. Isolation from a coleopteran insect of a novel inducible antibacterial peptide and of new members of the insect defensin family. J Biol Chem 1991; 266:24520-5. [PMID: 1761552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Injection of heat-killed bacteria into larvae of the large tenebrionid beetle Zophobas atratus (Insecta, Endopterygota, Coleoptera) results in the appearance in the hemolymph of a potent antibacterial activity as evidenced by a plate growth inhibition assay. We have isolated three peptides (A-C) from this immune hemolymph which probably account for most of this activity. Their primary structures were established by a combination of peptide sequencing and molecular mass determination by mass spectrometry. Peptide A, which is bactericidal against Gram-negative cells, is a 74-residue glycine-rich molecule with no sequence homology to known peptides. We propose the name coleoptericin for this novel inducible antibacterial peptide. Peptides B and C are isoforms of a 43-residue peptide which contains 6 cysteines and shows significant sequence homology to insect defensins, initially reported from dipteran insects. This peptide is active against Gram-positive bacteria. The results are discussed in connection with recent studies on inducible antibacterial peptides present in the three other major orders of the endopterygote clade of insects: the Lepidoptera, Diptera, and Hymenoptera.
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Affiliation(s)
- P Bulet
- Laboratoire de Biologie Générale, Université Louis Pasteur, Strasbourg, France
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32
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Lepage P, Bitsch F, Roecklin D, Keppi E, Dimarcq JL, Reichhart JM, Hoffmann JA, Roitsch C, Van Dorseelaer A. Determination of disulfide bridges in natural and recombinant insect defensin A. Eur J Biochem 1991; 196:735-42. [PMID: 2013293 DOI: 10.1111/j.1432-1033.1991.tb15872.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The primary-structure comparison of natural insect defensin A from Phormia terranovae and recombinant insect defensin A from Saccharomyces cerevisiae has been accomplished using a combination of Edman degradation and liquid secondary ion mass spectrometry. The natural and recombinant proteins have the same primary structure with identical disulfide-bond designations (formula; see text) as determined from the peptides obtained after thermolysin digestion. The combined use of Edman degradation and mass spectometry allowed the disulfide-bridge structure to be determined with a total of only 40 micrograms (9.9 nmol) natural peptide. Mass spectrometry provides a rapid means of disulfide-bridge verification, requiring not more than 20 micrograms recombinant insect defensin A, which is compatible with use in batch analysis.
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Affiliation(s)
- P Lepage
- Transgène S. A., Strasbourg, France
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33
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Wicker C, Reichhart JM, Hoffmann D, Hultmark D, Samakovlis C, Hoffmann JA. Insect immunity. Characterization of a Drosophila cDNA encoding a novel member of the diptericin family of immune peptides. J Biol Chem 1990; 265:22493-8. [PMID: 2125051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Drosophila shows an immune response when challenged by injection of low doses of bacteria. To date, the molecules involved in this immune reaction have remained elusive, with the exception of cecropins (4-kDa antibacterial peptides initially isolated from the moth Hyalophora cecropia) for which three closely related genes have been characterized recently. We report the molecular cloning and sequencing of a cDNA from a library of immune Drosophila which encodes a novel member of the family of diptericins (9-kDa antibacterial peptides initially isolated from the fly Phormia terranovae). Transcripts for the Drosophila diptericin are detected 2 h after injection of bacteria. They are apparently derived from a single gene mapping at position 56 A on the right arm of the second chromosome. We discuss the existence of a distant relationship between the diptericins and two other groups of anti-bacterial insect proteins, the attacins, and the sarcotoxins II.
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Affiliation(s)
- C Wicker
- Laboratoire de Biologie Générale de l'Université Louis Pasteur, Strasbourg, France
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34
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Wicker C, Reichhart JM, Hoffmann D, Hultmark D, Samakovlis C, Hoffmann JA. Insect immunity. Characterization of a Drosophila cDNA encoding a novel member of the diptericin family of immune peptides. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)45732-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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35
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Affiliation(s)
- J M Reichhart
- Laboratoire de Biologie Générale de l'Université Louis Pasteur, Strasbourg, France
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36
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Dimarcq JL, Zachary D, Hoffmann JA, Hoffmann D, Reichhart JM. Insect immunity: expression of the two major inducible antibacterial peptides, defensin and diptericin, in Phormia terranovae. EMBO J 1990; 9:2507-15. [PMID: 2369900 PMCID: PMC552280 DOI: 10.1002/j.1460-2075.1990.tb07430.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Injections of low doses of bacteria into larvae of Phormia terranovae induce the appearance of potent bactericidal peptides in the blood, among which predominate the anti-Gram positive insect defensins and the anti-Gram negative diptericins. Insect defensins show significant homologies to mammalian (including human) microbicidal peptides present in polymorphonuclear leukocytes and macrophages. We report the molecular cloning of cDNAs and primer extension studies which indicate that insect defensin is produced as a prepro-peptide yielding mature defensin A (40 residues) after cleavage of a putative signal peptide (23 residues) and a prosequence (34 residues). Previous studies have established that diptericin (82 residues) is matured from a pre-peptide by cleavage of a putative signal peptide (19 residues) and C-terminal amidation. Using oligonucleotide probes complementary to the sequences of the mRNAs for defensin and diptericin, we show by in situ hybridization that both antibacterial peptides are concomitantly synthesized by the same cells: thrombocytoids, a specialized blood cell type, and adipocytes. Transcriptional studies based on hybridization of RNAs to cDNAs of defensin and diptericin indicate that the transcription of both genes is induced regardless of the nature of the stimulus (injection of Gram positive or Gram negative bacteria, lipopolysaccharides). Even a sterile injury applied to axenically raised larvae is efficient in inducing the transcription of both genes suggesting that the local disruption of the integument aspecifically initiates a signalling mechanism which the thrombocytoids and the adipocytes are able to interpret. The transcription of immune genes is relatively short lived and a second challenge yields a response similar to that of the first stimulus, indicating that the experimental insects do not keep a 'memory' of their first injection.
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Affiliation(s)
- J L Dimarcq
- Laboratoire de Biologie Générale, Unité de Recherche Associée au CNRS Endocrinologie et Immunologie des Insectes, Strasbourg, France
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37
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Rosenthal GA, Reichhart JM, Hoffmann JA. L-canavanine incorporation into vitellogenin and macromolecular conformation. J Biol Chem 1989; 264:13693-6. [PMID: 2760038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
L-Canavanine is a potentially deleterious arginine antimetabolite whose toxicity is expressed in canavanine-sensitive organisms ranging from viruses to humans. Canavanine, a substrate for arginyl-tRNA synthetase, is incorporated into nascent polypeptide chains in place of arginine. This substitution results in the production of structurally aberrant, canavanyl proteins. Chemical, physical, and immunological studies of native and canavanine-containing vitellogenin obtained from female migratory locusts (Locusta migratoria migratorioides (Orthoptera] provide the first experimental evidence that canavanine can disrupt the tertiary and/or quaternary structure that yields the three-dimensional conformation unique to the protein. These findings enhance our understanding of the biochemical basis for canavanine's antimetabolic and potent insecticidal properties.
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Affiliation(s)
- G A Rosenthal
- T. H. Morgan School of Biological Sciences, University of Kentucky, Lexington 40506-0225
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38
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39
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Reichhart JM, Essrich M, Dimarcq JL, Hoffmann D, Hoffmann JA, Lagueux M. Insect immunity. Isolation of cDNA clones corresponding to diptericin, an inducible antibacterial peptide from Phormia terranovae (Diptera). Transcriptional profiles during immunization. Eur J Biochem 1989; 182:423-7. [PMID: 2544427 DOI: 10.1111/j.1432-1033.1989.tb14848.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have previously isolated and characterized a family of novel 8-kDa cationic antibacterial peptides synthesized by larvae of Phormia terranovae (Diptera) in response to various injuries. These molecules have been named diptericins. The peptide sequence of diptericin A was used to prepare oligonucleotides for screening cDNA libraries and we report in the present paper the isolation of several cDNA clones encoding diptericin. The analysis of the nucleotide sequences indicates that diptericin is synthesized as a prepeptide which is matured in two steps: (a) cleavage of a signal peptide and (b) amidation of the C-terminal residue. Interestingly, the 3' untranslated region of the mRNA contains a consensus sequence TTATTTAT which is also observed in the mRNA of another insect antibacterial peptide (attacin-related sarcotoxin IIA) and in mRNAs encoding proteins related to the inflammatory response in mammals. Our data illustrate that diptericins form a polymorphic family of immune peptides. The transcription of the diptericin genes is rapidly induced in the fat body after inoculation of bacteria, as evidenced by the transcriptional profile.
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Affiliation(s)
- J M Reichhart
- Laboratoire de Biologie Générale, Université Louis Pasteur, UA CNRS 672 Endocrinologie et Immunologie des Insectes, Strasbourg, France
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40
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Lambert J, Keppi E, Dimarcq JL, Wicker C, Reichhart JM, Dunbar B, Lepage P, Van Dorsselaer A, Hoffmann J, Fothergill J. Insect immunity: isolation from immune blood of the dipteran Phormia terranovae of two insect antibacterial peptides with sequence homology to rabbit lung macrophage bactericidal peptides. Proc Natl Acad Sci U S A 1989; 86:262-6. [PMID: 2911573 PMCID: PMC286444 DOI: 10.1073/pnas.86.1.262] [Citation(s) in RCA: 218] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We have isolated from the hemolymph of immunized larvae of the dipteran insect Phormia terranovae two peptides that are selectively active against Gram-positive bacteria. They are positively charged peptides of 40 residues containing three intramolecular disulfide bridges and differ from one another by only a single amino acid. These peptides are neither functionally nor structurally related to any known insect immune response peptides but show significant homology to microbicidal cationic peptides from mammalian granulocytes (defensins). We propose the name "insect defensins" for these insect antibiotic peptides.
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Affiliation(s)
- J Lambert
- Unité Associée au Centre National de la Recherche Scientifique, Laboratoire de Biologie Générale, Strasbourg, France
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41
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Dimarcq JL, Keppi E, Dunbar B, Lambert J, Reichhart JM, Hoffmann D, Rankine SM, Fothergill JE, Hoffmann JA. Insect immunity. Purification and characterization of a family of novel inducible antibacterial proteins from immunized larvae of the dipteran Phormia terranovae and complete amino-acid sequence of the predominant member, diptericin A. Eur J Biochem 1988; 171:17-22. [PMID: 3276515 DOI: 10.1111/j.1432-1033.1988.tb13752.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Injury or injection of live bacteria into third instar larvae of the dipteran insect Phormia terranovae results in the appearance in the haemolymph of at least five groups of heat-stable, more or less basic peptides with antibacterial activity against Escherichia coli. Three of these peptides have been purified. The amino acid sequence has been completely established for one of these and partially (first 40 residues from the N-terminus) for the two others. The sequences show marked homologies indicating that the three peptides belong to a common family. They are not related to other known antibacterial peptides from insects [lysozymes, cecropins (including sarcotoxin I) and attacins]. We propose the name of diptericins for this new family of antibiotic molecules.
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Affiliation(s)
- J L Dimarcq
- Unité Associée au Centre National de la Recherche Scientifique, Université Louis Pasteur, Strasbourg, France
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Freund-Mercier MJ, Stoeckel ME, Palacios JM, Pazos A, Reichhart JM, Porte A, Richard P. Pharmacological characteristics and anatomical distribution of [3H]oxytocin-binding sites in the Wistar rat brain studied by autoradiography. Neuroscience 1987; 20:599-614. [PMID: 3647280 DOI: 10.1016/0306-4522(87)90113-8] [Citation(s) in RCA: 167] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Oxytocin-binding sites were detected by autoradiography on rat brain sections incubated in the presence of the [3H]oxytocin. These sites were characterized pharmacologically using quantitative autoradiography. High pressure liquid chromatography controls of the incubation media indicated that labelling was due to the intact [3H]oxytocin molecule. Pharmacological analysis of different locations (central amygdaloid nucleus, ventral subiculum and ventromedial hypothalamic nucleus) showed that the sites detected had a high affinity for oxytocin and also for arginine-vasopressin. In contrast, some areas known to bind vasopressin intensely, such as suprachiasmatic and lateral septum nuclei, had little or no affinity for oxytocin. Autoradiographs revealed [3H]oxytocin-binding sites in already known brain areas (olfactory centres, ventral subiculum, central amygdaloid nucleus, bed nucleus of the stria terminalis) albeit with more extensive labelling of some of these formations, in particular, the amygdaloid complex. In addition, specific [3H]oxytocin-binding sites were found in areas not yet reported to bind oxytocin, such as the paraventricular thalamic and caudate nuclei. In the hypothalamus, specific binding sites were not detected in the supraoptic and paraventricular nuclei: the only structure labelled was the ventrolateral part of the ventromedial nucleus. Discrepancies between the concentrations of [3H]oxytocin-binding sites, the known distribution of oxytocin-containing endings and electrophysiological data indicate that autoradiography, under our conditions, apparently only reveals some of the oxytocin receptors in the brain. Thus, in the hypothalamus, no relationship can be established between the known effect of oxytocin on oxytocinergic magnocellular neurons and detection of specific [3H]oxytocin-binding sites. Autoradiography may reveal mainly oxytocin-binding sites in areas receiving diverse "parasynaptic" information, where oxytocin might play a modulatory role rather than exerting rapid, short-term effects of the neurotransmitter type.
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Grau Y, Reichhart JM, Thiebold J. Growth stimulation of the immature chick oviduct by androgens: the vagina as a new target tissue. J Embryol Exp Morphol 1985; 85:81-93. [PMID: 2580932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Testosterone when injected alone stimulates growth of the vagina but is inactive upon the other segments of the oviduct of the immature chicken. This action of testosterone can already be detected in embryos: it is expressed by the beginning of differentiation of the vaginal mesenchyme cells into smooth muscle cells. In the treated immature chicken, stimulation of growth is considerable and is specifically caused by androgens (testosterone and 5-alpha-dihydrotestosterone); the vaginal mesenchyme differentiates into two smooth muscular layers and vaginal epithelium cells differentiate into ciliated cells and goblets cells. [3H]testosterone binding has been found in the vagina of the immature chicken (data not shown). The characteristics of testosterone binding to cytoplasmic components of the chick vagina are consistent with its identity as a testosterone receptor.
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