Vibrio aestuarianus zinc metalloprotease causes lethality in the Pacific oyster Crassostrea gigas and impairs the host cellular immune defenses

International audience Extracellular products (ECPs) of the pathogenic Vibrio aestuarianus 01/32 were previously reported to display lethality in Crassostrea gigas oysters and to cause morphological changes and immunosuppression in oyster hemocytes. To identify the source of this toxicity, biochemic...

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Published in:Fish & Shellfish Immunology
Main Authors: Labreuche, Yannick, Le Roux, Frédérique, Henry, Joël, Zatylny-Gaudin, Céline, Huvet, Arnaud, Lambert, Christophe, Soudant, Philippe, Mazel, Didier, Nicolas, Jean-Louis
Other Authors: Physiologie et Ecophysiologie des Mollusques Marins (PE2M), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Lagons, Ecosystèmes et Aquaculture Durable de Nouvelle Calédonie (LEADNC), Laboratoire de Génétique et Pathologie (LGP), Amélioration génétique, du contrôle des performances et de la santé des mollusques marins (AGSAE), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Plasticité du Génome Bactérien (PGB), Institut Pasteur Paris (IP)-Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), This work was supported by the MOREST national project funded by IFREMER and by the Régions Basse-Normandie, Bretagne, Pays de la Loire and Poitou-Charentes and the Conseil Général du Calvados. We thank Patricia Mirella Da Silva and Philippe Miner for technical assistance and helpful discussions during the course of this work.
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2010
Subjects:
DNA
Online Access:https://hal.univ-brest.fr/hal-00670371
https://doi.org/10.1016/j.fsi.2010.07.007
Description
Summary:International audience Extracellular products (ECPs) of the pathogenic Vibrio aestuarianus 01/32 were previously reported to display lethality in Crassostrea gigas oysters and to cause morphological changes and immunosuppression in oyster hemocytes. To identify the source of this toxicity, biochemical and genetic approaches were developed. ECP protease activity and lethality were shown to be significantly reduced following incubation with metal chelators, suggesting the involvement of a zinc metalloprotease. An open reading frame of 1836 bp encoding a 611-aa metalloprotease (designated yam) was identified. The deduced protein sequence showed high homology to other Vibrio metalloproteases reported to be involved in pathogenicity. To further confirm the role of this enzyme in ECP toxicity, a plasmid carrying the yarn gene under the control of an araC-P(BAD) expression cassette was transferred to a Vibrio splendidus related strain, LMC20012(T), previously characterized as non-pathogenic to oysters. Expression of Vam conferred a toxic phenotype to LMG20012(T) ECPs in vivo and cytotoxicity to oyster hemocytes in vitro. Collectively, these data suggest that the Vam metalloprotease is a major contributor to the toxicity induced by V aestuarianus ECPs and is involved in the impairment of oyster hemocyte functions.