Background: To investigate the immunological and virological efficacy of the therapeutic vaccine HBV CS1, a recombinant fusion protein which is composed of HBV core aa 1-155 plus PreS1 aa 3-55,against chronic HBV infection.
Methods: HBV transgenic mice were immunized with HBV CS1(5 ug) emulsified in equal volume of complete Freund adjuvant on day 0, followed by a second vaccination with HBV CS1(5 ug) emulsified with incomplete Freund adjuvant on days 21. Mice of control group were mock-vaccinated with PBS plus complete Freund adjuvant/incomplete Freund adjuvant. The splenocytes of individual mouse were subjected to T cell proliferation assays by using 3Hg thymidine, HBsAg and HBV DNA in sera of mice were detected by ELISA and quantitative PCR, respectively.
Results: HBV CS1 specific T cell response were induced in mice immunized with HBV CS1, with the titer of HBsAg and the level of HBV DNA decreased significantly after twice immunization with HBV CS1, while the control group almost remained the same.
Conclusion: HBV CS1 has the immunological and virological efficacy against chronic HBV infection in HBV transgenic mice; HBV CS1 could represent candidate vaccine for further studies on its role as therapeutic vaccine against HBV chronic infection in human.