Distinct immune responses of juvenile and adult oysters (Crassostrea gigas) to viral and bacterial infections

• Main Authors: Green, Timothy, Vergnes, Agnes, Montagnani, Caroline, Lorgeril, Julien
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Figshare 2016
• Subjects: Medicine; Microbiology; FOS Biological sciences; Genetics; Physiology; Biotechnology; 59999 Environmental Sciences not elsewhere classified; FOS Earth and related environmental sciences; Ecology; Science Policy; Immunology; FOS Clinical medicine; 69999 Biological Sciences not elsewhere classified; Developmental Biology; Cancer; 111714 Mental Health; FOS Health sciences; 110309 Infectious Diseases; Computational Biology; Pacific; Crassostrea gigas
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.3638876.v1; https://figshare.com/collections/Distinct_immune_responses_of_juvenile_and_adult_oysters_Crassostrea_gigas_to_viral_and_bacterial_infections/3638876/1

Abstract Since 2008, massive mortality events of Pacific oysters (Crassostrea gigas) have been reported worldwide and these disease events are often associated with Ostreid herpesvirus type 1 (OsHV-1). Epidemiological field studies have also reported oyster age and other pathogens of the Vibrio genus are contributing factors to this syndrome. We undertook a controlled laboratory experiment to simultaneously investigate survival and immunological response of juvenile and adult C. gigas at different time-points post-infection with OsHV-1, Vibrio tasmaniensis LGP32 and V. aestuarianus. Our data corroborates epidemiological studies that juveniles are more susceptible to OsHV-1, whereas adults are more susceptible to Vibrio. We measured the expression of 102 immune-genes by high-throughput RT-qPCR, which revealed oysters have different transcriptional responses to OsHV-1 and Vibrio. The transcriptional response in the early stages of OsHV-1 infection involved genes related to apoptosis and the interferon-pathway. Transcriptional response to Vibrio infection involved antimicrobial peptides, heat shock proteins and galectins. Interestingly, oysters in the later stages of OsHV-1 infection had a transcriptional response that resembled an antibacterial response, which is suggestive of the oysterâ s microbiome causing secondary infections (dysbiosis-driven pathology). This study provides molecular evidence that oysters can mount distinct immune response to viral and bacterial pathogens and these responses differ depending on the age of the host.