A genetic immunization adjuvant system based on BVP22-antigen fusion

DNA vaccines must induce a greater immune response to be effective in the b iomedical industry. Therefore, we tested the trafficking trait of the bovin e herpesvirus 1 (BHV-1) protein VP22 (BVP22) fused to an antigen and applie d this unique trait to genetic immunization. DNA immunization with BVP22-an tigen stimulates immune responses superior to that of standard DNA immuniza tion. Mice were injected intramuscularly with gene constructs expressing th e antigen yellow fluorescent protein (YFP), YFP fused to BVP22, or YFP fuse d to BHV-1 tegument protein VP16 (BVP16). The results revealed a significan tly enhanced YFP antibody response with BVP22-YFP DNA immunization compared with either YFP or BVP16-YFP gene immunization. Notably, the BVP22-YFP DNA construct induced a stronger T helper 1 (Th1) response, based on IFN-gamma and IL-4 cytokine levels, and IgG2a/IgG1 ratios. Furthermore, BVP22-YFP ge netic immunization induced a greater cytotoxic T lymphocyte response. The g enetic adjuvant properties of BVP22 can make DNA vaccines much more effecti ve clinically.