Abstract: To study the celluar immune responses of HBV transgenic （Tg） mice induced by genetic recombinant Hepatitis B vaccine，the HBV transgenic mice were immunized by Hepatitis B vacc-ine，and killed at different period. The spleen were removed, and lymphocyte were separated and divided into two parts. One were cultured for 48h with HBsAg and assayed for IL-2 and IFN-Yand the other part were labelled with 3H-TdR after cultured for 56 h，and cultured for another 16h. The culture were harvested and the cpm was determined by using a liquid scintillation counter. The result showed that the Thl cytokine production and lymphocyte proliferation of HBV Tg mice after repeated immunization for 8 months were much higher than those of immunized one time for 1 week. But after immunized as normal style with different doses,the IL-2 level were not different to one time immunization. The results suggested that the high dose with repeated immunization might broken the immunized tolerance of HBV Tg mice and upregulate cella-ar responses.

Key words: Hepatitis B vaccine , Transgenic mice , immunization tolerance, Thl cytokine, T lym-phocyte proliferation