丙型肝炎病毒复合高变区1模拟表位蛋白的免疫原性分析

Immunogenicity of a Hepatitis C Virus Multiple-mimotope Protein of Hypervariable Region 1

将丙型肝炎病毒高变区1(HVR1)模拟表位融合基因插入原核表达载体pGEX-4T-1,在大肠杆菌BL21(DE3)中进行表达,经亲和层析和凝胶过滤层析获得HCVHVR1模拟表位融合蛋白。用Westernblot和ELISA检测融合蛋白与HCV抗体阳性血清的结合情况。皮下注射免疫BALB/c小鼠,用ELISA检测小鼠血清中的抗HCV抗体水平及其与天然HCV高变区1合成肽的交叉反应。结果表明融合蛋白能与HCV抗体阳性血清特异结合,融合蛋白与HCV抗体阳性血清的结合频率为71.6%(25/35)。融合蛋白免疫小鼠后能有效诱导免疫应答,其诱生的特异性抗体最高滴度达104(免疫后第8周),且该抗体能同2条天然HCVHVR1合成肽发生交叉反应。本研究提示,HCV复合HVR1模拟表位融合蛋白在丙型肝炎疫苗的研发中可能具有潜在应用价值。

A synthesized multiple-mimotope gene of Hepatitis C virus was cloned into a prokaryotic expression vector pGEX-4T-1 to generate a fusion protein GST-HCVME. The reactivity of the GSTHCVME with the sera of HCV patients was measured by Western-blot and ELISA. BALB/c mice were injected with GST-HCVME, and an ELISA approach was applied to determine the specific antibody titers in the mouse serum. The cross-reactivity of the antibodies was also checked with 2 synthesized HCV hyper-variable region 1 （HVR1） peptides. The results showed that the purified GST-HCVME fusion protein was able to react with 25 out of 35 HCV patients＇ serum samples. The serum antibody response was effectively elicited in BALB/c mice injected with GST-HCVME. The highest titer of antibody against HCV （GST-HCVME） was about 1：10^4 at the eighth week after first immunization. Moreover, the collected mouse serum antibody had the ability to cross-react with the 2 synthesized HCV HVR1 peptides. These findings suggest that the multiple-mimotope protein of hepatitis C virus can efficiently induce HCV-specific immune responses in mice, and may be of potential use in the development of HCV vaccines.