CpG-ODN 2007 protects zebrafish against Vibrio vulnificus-induced infection

Vibrio vulnificus (V. vulnificus) is an aquatic pathogen that can cause primary sepsis and soft tissue infection. CpG oligodeoxynucleotides (CpG-ODN) are a type of essential immunomodulators, which can trigger or enhance immune responses in mammals, fish, and humans. In this study, we evaluated the effect of CpG-ODN 2007 as a potential immunostimulant for zebrafish infected with V. vulnificus (FJ03-X2). Fish injected with the CpG-ODN 2007 showed lower mortality rate compared with the fish that did not receive treatment. The survival rates of CpG-ODN 2007-treated group and PBS-treated group were 85% and 57.9%, respectively. In addition, our in vitro results demonstrated that CpG-ODN 2007 can effectively reduce the toxicity of V. vulnificus (FJ03-X2) to zebrafish embryonic fibroblast (ZF4) cells. Furthermore, we assessed immune-related genes expression patterns in FJ03-X2 infected zebrafish or ZF4 cells with and without CpG-ODN 2007 treatment, such as TLRs and IL-1{beta}. To sum up, our data indicated that CpG-ODN 2007 protects zebrafish against Vibrio vulnificus induced infection.