Cellular and molecular hemocyte responses of the Pacific oyster, Crassostrea gigas, following bacterial infection with Vibrio aestuarianus strain 01/32

• Published in: Microbes and Infection
• Main Authors: Labreuche, Yannick, Lambert, Christophe, Soudant, Philippe, Boulo, Viviane, Huvet, Arnaud, Nicolas, Jean-Louis
• Other Authors: Physiologie et Ecophysiologie des Mollusques Marins (PE2M), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), 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 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), Génome, populations, interactions, adaptation (GPIA), Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université Montpellier 2 - Sciences et Techniques (UM2)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: bivalve immunity; Vibrio aestuarianus; pathogenesis; oyster; Crassostrea gigas; envir; socio; Pacific; Pacific oyster
• Online Access: https://doi.org/10.1016/j.micinf.2006.07.020; https://hal.univ-brest.fr/hal-00670385

International audience The strategies used by bacterial pathogens to circumvent host defense mechanisms remain largely undefined in bivalve molluscs. In this study, we investigated experimentally the interactions between the Pacific oyster (Crassostrea gigas) immune system and Vibrio aestuarianus strain 01/32, a pathogenic bacterium originally isolated from moribund oysters. First, an antibiotic-resistant V. aestuarianus strain was used to demonstrate that only a limited number of bacterial cells was detected in the host circulatory system, suggesting that the bacteria may localize in some organs. Second, we examined the host defense responses to V. aestuarianus at the cellular and molecular levels, using flow-cytometry and real-time PCR techniques. We showed that hemocyte phagocytosis and adhesive capabilities were affected during the course of infection. Our results also uncovered a previously-undescribed mechanism used by a Vibrio in the initial stages of host interaction: deregulation of the hemocyte oxidative metabolism by enhancing the production of reactive oxygen species and down-regulating superoxide dismutase (Cg-EcSOD) gene expression. This deregulation may provide an opportunity to the pathogen by impairing hemocyte functions and survival. These findings provide new insights into the cellular and molecular bases of the host-pathogen interactions in C. gigas oyster.