Activation of anti-HBV immune activity by DNA vaccine via electroporation using heat shock proteins as adjuvant / 生物工程学报

ABSTRACT

Although DNA vaccination is now a promising strategy against hepatitis B virus (HBV) infection, this approach has relatively modest antiviral effect, indicating that immunosuppressive mechanisms may occur in the long-term established infection. In this study, we studied the immunogenicity and anti-HBV efficiency of a combination of HBV surface (HBsAg) and core (HBcAg) DNA vaccine, enhanced by heat shock protein (HSP) gp96 or HSP70 and mediated by in vivo electroporation. Immunization with gp96 adjuvanted HBsAg/HBcAg DNA formulation induced potent T cell and antibody immunity against HBsAg and HBcAg. Notably, treatment with gp96 or HSP70 as adjuvant resulted in reduction of Treg populations by around 20%. Moreover, compared with nonimmunized control mice, immunization with gp96 or HSP70 adjuvanted DNA vaccine dramatically decreased serum HBsAg and viral DNA levels, and HBcAg expression in liver. These results may therefore provide an effective strategy for designing gp96-based DNA vaccine for immunotherapy of chronic HBV infection.