Analysis of Immune Gene Expression in Seabass (Lates calcarifer) Immunized with Inactivated Vaccine against Similar Damselfish Virus

Abstract

Background: Control of viral disease outbreaks in aquaculture and minimizing the loss of production can be achieved by development of effective vaccines. Efficacy of these vaccines can be improved by using adjuvants, immunostimulants or vaccine carriers. In this study, inactivated similar damselfish virus (SRDV) vaccine was prepared and expression profiles of immune related genes against virus challenge of the vaccine were investigated in seabass (Lates calcarifer). Methods: Formalin-inactivated virus vaccine was developed to assess its immune responses to SRDV challenge in fish. The immune response was induced by intra-peritoneal injection with inactivated viral vaccine added Quil-A® adjuvant. The transcriptional levels of immune genes IRF-7 and IL-10 were evaluated in the spleen and kidney of seabass from different groups by quantitative real-time RT-PCR assays. Result: Expression profiles of both genes (IRF-7 and IL-10) in the kidney and spleen of seabass immunized with vaccine added adjuvant were up-regulated at 48 hpi of the virus. In comparison, spleen of seabass immunized with vaccine added adjuvant showed highest expression profiles than kidney. The current study provides evidence for the presence of expression profiles of immune-related genes during the SRDV infection. The study also strongly suggests that Quil-A® adjuvant enhances the immune response of the vaccine candidates.