Construction and evaluation of a chimeric vaccine against Clostridium perfringens type a of sika deer.

Clostridium perfringens α-toxins are lethal, neurotoxic factors that play a critical role in the pathogenesis of gas gangrene and hemorrhagic enteritis. In this study, the full-length α-toxin protein and two multi-epitope tandem proteins, CPA1 and CPA2, were recombinantly expressed using a prokaryotic expression system, and their immunogenic effects were evaluated in a mouse model. Compared with the full-length α-toxin, CPA1 and CPA2 induced comparable lymphocyte proliferation and differentiation, as well as sustained high antibody levels. Additionally, significantly elevated serum levels of cytokines IL-2, IL-4, and IL-10 were observed in mice immunized with CPA1 and CPA2. Protective efficacy against lethal toxin challenge was 70 % for CPA1 and 80 % for CPA2, as assessed relative to the α-toxin protein control. These findings suggest that CPA1 and CPA2 represent promising subunit vaccine candidates against Clostridium perfringens type A infection in sika deer.