DNA immunization with fusion genes containing HCV core region and HBV core region

The eucaryotic expression plasmids were constructed to express the complete (HCcl91) or the truncated (HCc69 and HCc40) HCV core genes, solely or fused with the HBV core gene (HBcl44). These constructions were transiently expressed in COS cells under the control of the CMV promoter. The antigenicity of HBc and HCc could be detected in the expression products by ELISA and Western blot. The mice immunized with these expression plasmids efficiently produced the anti-HCc antibodies, and also anti-HBc antibodies when the plasmids contained the fusion genes. In addition, the antibodies induced by the fusion genes were more persistent than those induced by the non-fusion HCV core genes. These indicate that the fusion of HCc genes to HBc gene is in favor of the immunogenicity of HCc, while the immunogenicity of HBc is not affected.