丙型肝炎病毒包膜基因对核心基因DNA疫苗免疫应答强度的影响

目的 研究丙型肝炎病毒(HCV)包膜基因E1E2对核心基因C DNA疫苗诱生的免疫应答作用。方法 将包含HCV C或CE1E2基因片段插入真核表达载体pcDNA3中,构建重组质粒pHCV-C或pHCV-CE1E2,分别免疫Balb/c小鼠,每间隔2wk加强免疫1次,同时剪尾取血。ELISA法检测免疫小鼠血清中HCV C特异性抗体的水平。以pHCV-C转染并表达HCcAg的BLAB/c小鼠骨髓瘤Sp4/0细胞为靶细胞,采用~(51)Cr释放试验检测特异性CTL的杀伤作用。结果 两个实验组20只小鼠均产生抗HCV C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(p<0.01);而pHCV-CE1E2与pHCV-C组之间,无论是抗HCV C抗体的滴度还是CTL的杀伤率均无显著性差异(p>0.05)。结论 E1E2基因的加入,并没有增加HCV C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。

Effect of HCV envelope gene on core DNA vaccine in mice

Objective 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 FLISA. CTL activity was measured by standard 4h~(51) Cr release assays. Spleen cells from experimental and control mice were extracted with routine method. The mouse myloma SP2/0 cells expressing HCV C antigen serve as target cells. Result 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.