Vibrio aestuarianus zinc metalloprotease causes lethality in the Pacific oyster Crassostrea gigas and impairs the host cellular immune defenses
|Author(s)||Labreuche Yannick1, 2, Le Roux Frederique3, 4, 5, Henry Joel6, Zatylny Celine6, Huvet Arnaud2, Lambert Christophe7, Soudant Philippe7, Mazel Didier3, 4, Nicolas Jean-Louis2|
|Affiliation(s)||1 : IFREMER, Dept Lagons Ecosyst & Aquaculture Durable Nouvell, Stn St Vincent, Noumea 98846, New Caledonia.
2 : IFREMER Physiol & Ecophysiol Mollusques Marins, Ctr Brest, UMR 100, F-29280 Plouzane, France.
3 : Inst Pasteur, Unite Plast Genome Bacterien, Dept Genomes & Genet, F-75015 Paris, France.
4 : CNRS, URA 2171, F-75015 Paris, France.
5 : IFREMER, Lab Genet & Pathol, F-17390 La Tremblade, France.
6 : Univ Caen Basse Normandie, IFREMER Physiol & Ecophysiol Mollusques Marins, Lab Biol & Biotechnol Marines, UMR 100, F-14032 Caen, France.
7 : Univ Bretagne Occidentale, Inst Univ Europeen Mer, Lab Sci Environm Marin, F-29280 Plouzane, France.
|Source||Fish & Shellfish Immunology (1050-4648) (Academic Press Ltd- Elsevier Science Ltd), 2010-11 , Vol. 29 , N. 5 , P. 753-758|
|WOS© Times Cited||59|
|Keyword(s)||Vibrio aestuarianus, Metalloprotease, Crassostrea gigas, Oyster, Hemocytes, Extracellular products|
|Abstract||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. (C) 2010 Elsevier Ltd. All rights reserved.|