[Enhancement of the immune response in mice with a noval HCV DNA vaccine targeting NS3 to dendritic cells].

To develop a new Hepatitis C virus (HCV) DNA vaccine ,We explored strategies for optimizing the immunogenicity of HCV DNA vaccine in fusion with dendritic cell-targeting molecules (scDEC, a single-chain antibody against the murine DC cell surface molecule DEC205). We constructed the DNA vaccine plasmids expressing the HCV non-structural protein NS3 alone or in combination with DEC205 as a fusion protein and identified the expression of the molecules of interest by transient transfection of 293 cells with the resultant DNA vaccine plasmids. Then BALB/C mice were immunized with these plasmids by the injection in combination with electroporation. The NS3-specific IgG antibody(ELISA) and cellular immunity (IFN-gamma ELISPOT) were analyzed post twice immunization. Our results showed that: the single-chain antibody against DEC205 fused with vaccine antigen NS3 significantly enhanced the immunogenicity of new HCV DNA vaccine, the intradermal injection in combination with electroporation using caliper electrodes resulted in most robust NS3-specific antibody and T cell immune response. In conclusion,immune response for the HCV NS3 protein-encoding DNA vaccine was enhanced significantly when targeting antigen NS3 to DCs by scDEC. The present strategy could merit further study in the context of other prophylactic and therapeutic DNA based vaccines.