title: Antimicrobial histones and DNA traps in invertebrate immunity: evidences in Crassostrea gigas.
abstract: Although antimicrobial histones have been isolated from multiple metazoan species, their role in host defense has long remained unanswered. We found here that the hemocytes of the oyster Crassostrea gigas release antimicrobial H1-like and H5-like histones in response to tissue damage and infection. These antimicrobial histones were shown to be associated with extracellular DNA networks released by hemocytes, the circulating immune cells of invertebrates, in response to immune challenge. The hemocyte-released DNA was found to surround and entangle vibrios. This defense mechanism is reminiscent of the neutrophil extracellular traps (ETs) recently described in vertebrates. Importantly, oyster ETs were evidenced in vivo in hemocyte-infiltrated interstitial tissues surrounding wounds, whereas they were absent from tissues of unchallenged oysters. Consistently, antimicrobial histones were found to accumulate in oyster tissues following injury or infection with vibrios. Finally, oyster ET formation was highly dependent on the production of reactive oxygen species by hemocytes. This shows that ET formation relies on common cellular and molecular mechanisms from vertebrates to invertebrates. Altogether, our data reveal that ET formation is a defense mechanism triggered by infection and tissue damage, which is shared by relatively distant species suggesting either evolutionary conservation or convergent evolution within Bilateria.
authors.affiliation: From Laboratory of Ecology of Coastal Marine Systems, CNRS UMR 5119, University of Montpellier 2, Ifremer, University of Montpellier 1, and IRD, Place Eugène Bataillon, F-34095 Montpellier, France.
authors.forename: Aurore C
authors.initials: AC
authors.lastname: Poirier
authors.affiliation: From Laboratory of Ecology of Coastal Marine Systems, CNRS UMR 5119, University of Montpellier 2, Ifremer, University of Montpellier 1, and IRD, Place Eugène Bataillon, F-34095 Montpellier, France, the Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, 2373223 Valparaíso, Chile, and.
authors.forename: Paulina
authors.initials: P
authors.lastname: Schmitt
authors.affiliation: From Laboratory of Ecology of Coastal Marine Systems, CNRS UMR 5119, University of Montpellier 2, Ifremer, University of Montpellier 1, and IRD, Place Eugène Bataillon, F-34095 Montpellier, France.
authors.forename: Rafael D
authors.initials: RD
authors.lastname: Rosa
authors.affiliation: From Laboratory of Ecology of Coastal Marine Systems, CNRS UMR 5119, University of Montpellier 2, Ifremer, University of Montpellier 1, and IRD, Place Eugène Bataillon, F-34095 Montpellier, France.
authors.forename: Audrey S
authors.initials: AS
authors.lastname: Vanhove
authors.affiliation: INSERM, Commissariat à l'Energie Atomique (CEA), Université Joseph Fourier, U1038, Etude de la Dynamique des Protéomes, Laboratoire Biologie à Grande Echelle, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Kieffer-Jaquinod
authors.affiliation: From Laboratory of Ecology of Coastal Marine Systems, CNRS UMR 5119, University of Montpellier 2, Ifremer, University of Montpellier 1, and IRD, Place Eugène Bataillon, F-34095 Montpellier, France.
authors.forename: Tristan P
authors.initials: TP
authors.lastname: Rubio
authors.affiliation: From Laboratory of Ecology of Coastal Marine Systems, CNRS UMR 5119, University of Montpellier 2, Ifremer, University of Montpellier 1, and IRD, Place Eugène Bataillon, F-34095 Montpellier, France, guillaume.charriere@univ-montp2.fr.
authors.forename: Guillaume M
authors.initials: GM
authors.lastname: Charrière
authors.affiliation: From Laboratory of Ecology of Coastal Marine Systems, CNRS UMR 5119, University of Montpellier 2, Ifremer, University of Montpellier 1, and IRD, Place Eugène Bataillon, F-34095 Montpellier, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Destoumieux-Garzón
mesh_terms: D056704:Adaptive Immunity / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D001419:Bacteria / Q000145:classification / Q000187:drug effects; D049896:Crassostrea / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D065206:Extracellular Traps / Q000276:immunology* / Q000378:metabolism; D006434:Hemocytes / Q000276:immunology / Q000378:metabolism; D006657:Histones / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D054884:Host-Pathogen Interactions / Q000276:immunology; D007448:Invertebrates / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D017382:Reactive Oxygen Species / Q000276:immunology / Q000378:metabolism; D014733:Vibrio / Q000276:immunology / Q000502:physiology
chemical_list: D000890:Anti-Infective Agents; D006657:Histones; D017382:Reactive Oxygen Species
keywords: Antimicrobial Peptide (AMP); DNA; Innate Immunity; Invertebrate; Mollusk; NET; Reactive Oxygen Species (ROS)