| 论文摘要： |
Precise identification of protective antigenic epitopes is critical not only for eliciting robust and specific immune responses but also for providing a vital foundation for vaccine development and monoclonal antibody engineering. In this study, we cloned six constructs, five truncated major capsid protein (MCP) of largemouth bass virus (LMBV) fragments (MCP-1, MCP-2, MCP-3, MCP-4, MCP-1&3) and the full-length MCP, into pET-32a expressed them in a prokaryotic system, and evaluated their antigenicity. Furthermore, the antigen protein was administered to fish in a four-week immunization trial. This study demonstrated that MCP-3 markedly enhanced both innate and adaptive immune responses. We also observed a pronounced expansion of IgM+ and IgT+ B cell populations. Notably, MCP-3 enhanced the titers of both serum and mucosal antigen-specific IgM and conferred the strongest neutralizing activity against LMBV. Challenge experiments further confirmed that the MCP-3 group achieved the highest relative percent survival (RPS = 88.89 %) and the lowest post-infection tissue viral loads. In summary, these results indicate that we have identified MCP-3 as a key protective antigen of LMBV, which may serve as a promising target for vaccine development to prevent and control LMBV infection. |
