重组质粒与重组蛋白共免疫诱导HBsAg特异性T细胞免疫抑制

摘要：【目的】为了探索治疗急性乙型肝炎和爆发性乙型肝的新策略，本研究将HBV DNA疫苗和相应抗原的蛋白质分子联合免疫小鼠，旨在探讨联合免疫对小鼠抗原特异性T细胞增殖反应的影响。【方法】我们将HBV DNA疫苗（pcDS2）和相应抗原蛋白质分子(HBsAg)联合免疫BALB/c小鼠；分别在第0、2和4周进行免疫，在第6周用ELISA方法检测抗-HBs IgG效价，MTT和流式细胞仪检测T细胞增殖反应，及流式细胞仪检测细胞因子表达水平。【结果】pcDS2和HBsAg联合免疫组小鼠的抗-HBs水平显著提高；免疫小鼠的T细胞体外经HBsAg刺激后, 联合免疫组刺激指数(SI)明显降低；经流式细胞仪检测进一步证实联合免疫组T细胞增殖反应被显著抑制；联合免疫组T细胞表达IL-10和Foxp3水平显著升高。【结论】pcDS2和HBsAg联合免疫能诱导产生特异性体液免疫应答，但不能诱导产生抗原特异性T细胞增殖反应；T细胞增殖反应被显著抑制可能与T细胞表达IL-10和Foxp3上调有关；本研究为急性乙型肝炎和爆发性乙型肝炎治疗及HBV疫苗的研究奠定了基础。

Suppression of the antigen-specific T cell immune response by co-immunization with the HBV DNA vaccine and recombinant HBsAg

Objective] To explore a new therapeutic strategy against acute hepatitis B and fulminant hepatitis B, we studied effect of co-immunization with HBV DNA and HBsAg on the T cell proliferation reaction. Methods] We immunized the BALB/ c mice with HBV DNA vaccine (pcDS2) plus HBsAg by intramuscular injection. The immunization was performed on week 0, 2 and 4. The anti-HBs(IgC)antibody titer, T lymphocyte proliferation reaction , and the expression of IL-10 and Foxp3 in CD3 + T cell were detected on week 6. Results] The anti-HBs IgC titer induced by pcDS2 plus HBsAg group was higher than that induced by pcDS2, or HBsAg alone. Compared to mice immunized with pcDS2, or HBsAg alone, the stimulated index (SI) of T cell proliferation induced by the pcDS2 plus HBsAg group tested by MTT methods decreased. Besides, the immune suppression of T cell proliferation response induced by co-immunization group was further confirmed by flow cytometry. Finally, the expression of IL-10 and Foxp3 in CD3+ T cell was up-regulated in the co-immunization group significantly. Conclusion] The co-immunization of HBV DNA vaccine and HBsAg can induce the humoral immune response, but cannot induce antigen specific T cell proliferation reaction. Besides, the immune suppression induced by co-immunization may be correlated with the expression of IL-10 and Foxp3.