两种HCV不同结构基因重组质粒DNA诱导免疫应答的比较研究

Immune effect of HCV envelope and core DNA vaccine in mice

目的探讨丙型肝炎病毒HCV包膜基因E1E2,对核心基因CDNA疫苗诱生的免疫应答有无增强作用。方法构建包含HCVC或CE1E2基因片段的真核表达载体pHCVC和pHCVCE1E2,分别接种于Balb/c小鼠股四头肌以空载体pcDNA3作为对照,每间隔2wk加强免疫1次。用ELISA法检测免疫小鼠血清中抗HCVC特异性抗体的产生。以pHCVC转染并表达HCcAg的Sp2/0细胞为靶细胞,采用51Cr释放试验检测特异性CTL的杀伤作用。结果两个实验组免疫的20只小鼠均产生抗HCVC特异性抗体,当效/靶细胞比例为100∶1时,CTL的杀伤率均明显高于对照组P0.01;而pHCVCE1E2与pHCVC组之间,无论是抗HCVC抗体的滴度还是CTL的杀伤率均无显著性差异P0.05。结论E1E2基因的加入,并没有增加HCVC基因DNA疫苗诱导的抗HCcAg特异性抗体的滴度和CTL的杀伤作用。

Aim To investigate the enhancing effect of envelope gene (E1E2) on immune responses of HCV core (C) gene induction in mice. Methods Balb/c mice were immunized with the recombinant plasmid containing HCV core (pHCV C) or full length structural gene (pHCV CE1E2). HCV C specific antibody in the sera was measured with ELISA. CTL activity was measured by standard 4 h 51Cr release assays. Spleen cells from experimental and control mice were extracted with routine method. The mouse myeloma Sp2/0 cells expressing HCV C antigen served as target cells. Results The plasmid pHCV CE1E2 didn′t enhance HCV core specific antibody level and CTL activity compared with control mice immunized with pHCV C. Conclusion The envelope gene could not improve HCV core specific antibody level and CTL activity. However, we cannot exclude from these data that there are not CTL epitopes in HCV envelope gene region.