Th1类细胞因子对pHCV—C重组体诱生免疫应答的增强作用

为了探索Th1类细胞因子IL 2和IL 12对含丙型肝炎病毒 (HCV)核心 (C)基因重组体诱生的免疫应答的增强作用 ,本文构建了包含HCVC基因片段的重组质粒pHCV C ,将其单独或与Th1类细胞因子表达质粒 pIL 2或pIL 12共免疫BALB/c小鼠 ,ELISA法检测免疫小鼠血清中的HCVC特异性抗体滴度 ;以pHCV C转染SP2 / 0细胞 ,经筛选稳定表达HCVC抗原者 (SP2 / 0 HCV C)为靶细胞 ,51Cr释放试验检测细胞毒T淋巴细胞 (CTLs)的体外特异性杀伤功能。结果发现 ,pIL 2能够增加 pHCV C诱导的抗体产生 ,对CTLs的杀伤作用增强却不明显 ;而 pIL 12对 pHCV C诱导的抗体和细胞免疫应答均有增强作用 (p <0 .0 5 )。由此推断 ,佐以Th1类细胞因子 ,不仅可以增强基因疫苗诱生的免疫应答强度 ,而且可能使机体对基因疫苗的免疫应答朝着有利于优先诱导CTLs免疫应答清除病原体的方向发展。

Enhancing Effect of Th1 Cytokine on Immune Responses of Mice to Recombinant Plasmid Encoding Hepatitis C Virus Core Gene

BALB/c mice were immunized with a recombinant plasmid containing HCV C gene (pcDNAHCV C) alone or together with a constructs encoding IL 2 or IL 12 (pIL 2 or pIL 12). Anti HCV C specific antibody in the sera was measured with ELISA. Spleen cells from experimental and control mice were extracted. The mouse myloma SP2/0 cells expressing HCV C antigen served as target cells. CTL activity was measured by standard 4h 51 Cr release assays. The results showed that anti HCV C antibody A value increased from 1.21 of pcDNAHCV C alone to 2.09 and 1.73 of pHCV C coimmunized with pIL 2 or pIL 12 respectively. CTL activity to HCV core protein was substantially enhanced after coimmunization with the IL 12 expressing plasmid. In contrast, the improvement of HCV core specific CTL activity with an IL 2 producing construct coimmunization was not obvious, which could related to the low level expression of IL 2 vector pDOR. DNA vaccine of HCV combined with IL 12 expressing plasmid could get better immunizing effects, and it might represent a gene therappeutic strategy against the HCV infection of human.