A novel hepatitis C virus vaccine approach using recombinant Bacillus Calmette-Guerin expressing multi-epitope antigen.

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. HCV infection is associated with high morbidity and has become a major problem in public health. Until now, there has been no effective prophylactic or therapeutic vaccine. BCG, a live vaccine typically used for tuberculosis prevention, has been increasingly utilized as a vector for the expression of recombinant proteins that will induce specific humoral and cellular immune responses. In this study, recombinant BCG (rBCG) was engineered to express a HCV multi-epitope antigen CtEm, and HLA-A2.1 transgenic mice were immunized with rBCG-CtEm. High levels of specific anti-HCV antibodies targeted to mimotopes of HVR1 were detected in the serum. HCV-specific lymphocyte proliferation assay, cytokine determination and cytotoxicity assay indicated that HCV epitope-specific cellular immune responses were elicited in vitro. The rBCG-CtEm immunization conferred protection against infection with the recombinant vaccinia virus (rVV-HCV-CNS) in vivo. These results suggest that rBCG expressing multi-epitope antigen may serve as an effective vaccine against HCV infection.