A novel mouse model for immunogenic evaluation of human HBV vaccines

To prepare a human HBV vaccine, investigators need an animal model that can help them screen and prioritize vaccine candidates. In this study, HBV/HLA-A2.1 double transgenic mice (dTg), confirmed by analysis of genomic integration and by observation of long-term expression of HBV and HLA genes, were generated for the first time. The HBV/HLA-A2.1 dTg not only display tolerance to HBV antigens (Ags), but also have the ability to process and present HLA-A2 restricted antigenic epitopes. The animals vaccinated with HLA-A2 restricted HBc(18-27) or HBs(183-191) epitope peptide vaccine induced effective HLA-A2 restricted peptide-specific cytolytic T lymphocyte responses. This was supported by the evidence of cytotoxicity assay, ELISPOT and tetramer staining analysis. Furthermore, T cell tolerance against HBV Ags in HBV/HLA-A2.1 dTg was broken by the HBc(18-27) or HBs(183-191) peptide vaccine. In conclusion, HBV/HLA-A2.1 dTg was demonstrated to be useful model for in vivo immunogenicity testing of human HBV-based vaccines.