DNA vaccine induced cellular immunity in healthy mice and HBsAg serum conversion in HBV transgenic mice / 中国免疫学杂志

ABSTRACT

Objective:To investigate the feasibility and its action of the therapeutic DNA vaccine for treatment of HBV infection.Methods:By genetic recombinant technique,have constructed 2 eukaryotic expressing plasmids namely pS2.S and pFP,encoding HBV envelope middle protein(preS2+HBsAg) and human leukocyte cytokines fusion protein(IL 2/IFN ?) genes respectively and evaluated its efficacy for inducing cellular immunity in healthy BALB/c mice and HBsAg serum conversion in HBV transgenic(Tg) mice after immunization of the plasmids by intramuscular administration.Results:1.The T cell proliferation by in vitro HBsAg stimulation closely correlated with HBsAg concentration,with its stimulation index(SI=5.6?0.9) in pS2.S immunized group,being significantly higher than that (2.0?0.5) of the control.The IL 2 and IFN ? secretion level in supernatant of the DNA vaccine immunized spleen cell culture were significantly higher than that of the control,while the IL 4 secretion level was not affected.2.The dendritic cells(DCs) extracted from the local draining lymph node(LN) after DNA vaccination induced a HBsAg specific T cell proliferation with its SI(4.20) being higher than that(2.55) of the control.3.In each group of high dose pS2.S and the middle dose combined with pFP inoculation,the HBsAg serum conversion occurred in one HBV Tg mouse,with the serum anti HBs level increasing as the time prolonged,while the serum HBsAg level of the rest mice were significantly lower than that of the control.Conclusion:The results suggest that HBV DNA vaccine can effectively induced cellular immunity in healthy mice;and the preliminary results of the immunized HBV Tg mice may provide an experimental evidence for further investigation of DNA vaccine for its use in treatment of HBV infection.