乙型、丙型肝炎DNA疫苗单次联合接种后小鼠的免疫应答

Study on the Immune Responses of Mice after Singly Inoculated with HBV and HCV Mixed DNA Vaccine

目的:观察由编码HBsAg与HCV-CE_2原的两种重组真核细胞表达质粒制备的DNA疫苗联合接种BALB/c小鼠后,其诱生特异性免疫应答的规律和相互影响。方法:应用上述2种DNA疫苗单次联合免疫小鼠,动态观察血中特异性抗体水平;并完成稳定转染,表达相应抗原的SP2/0骨髓瘤细胞的建株,采用CTL杀伤活性体内诱生实验的方法,建立观察DNA疫苗免疫保护与治疗效应的动物模型。结果:两种DNA疫苗单次联合免疫小鼠,能够共同诱生特异性机体免疫应答,但特异性抗体阳性率及滴度均不高;而CTL杀伤活性体内实验的结果则显示,经DNA疫苗联合接种免疫的小鼠荷瘤目的靶细胞后,其生存率明显高于未免疫鼠(P<0.05)。接种后特异性抗体呈阴性的小鼠也表现出相似的CTL保护效果。结论:DNA疫苗诱生的CTL应答可与体液免疫应答分离存在,而且可能是DNA疫苗免疫保护效应更重要的方面。

Aim: To study the immune response, of which the magnitude and strength after a mixed DNA vaccine of two kinds of eukaryotic expression plasmids encoded HBsAg and HCV-CE2 was singly inoculated BALB/c mice. Method: BALB/c mice singly inoculated with HBV and HCV mixed DNA vaccine, the immune response (special antibody and CTL) was compared between the immunization of this two kinds of plasmids separately and combined, along with the interaction of the two plasmids. The target cell line of stable transfection and expression of antigen was constructed, and the animal model of CTL test in vivo was first studied as a much advanced test compared with CTL test in vitro, which has a promising prospect both in preventive and therapeutic fields of studies. Results: The mixed DMA vaccine immunized mice induce immune response to both the plasmids. A weakly humoral response of mice to the expression products of S-gene and HCV-CE2 can be observed, meanwhile. the result of CTL test in vivo showed immuned mice has a prolonged life span after attacked by target cells (SP2/0 with expressing antigen), and there is a obvious value of the mixed vaccine , especially for HCV as the CTL response and memory cells were induced. Conclusion: This study created a simple, specific and effective method and gave some important information to further studies.