丙型肝炎病毒多表位基因核酸疫苗的构建及其免疫原性

目的构建丙型肝炎病毒(HCV)多表位基因的真核表达载体pcDNA3.1(-)-CtEm,用该重组质粒免疫BALB/c小鼠,并检测其免疫原性。方法用BamHⅠ和HindⅢ双酶切含有HCVC区、E2区模拟表位和NS3~NS5区细胞表位串联基因的原核表达载体pQE30-CtEm,克隆入真核表达载体pcDNA3.1(-),脂质体瞬时转染CHO细胞,并检测其表达。以100μg重组质粒免疫BALB/c小鼠,检测其体液免疫和细胞免疫效果。结果所构建的真核表达载体pcDNA3.1(-)-CtEm在CHO细胞中能获得有效表达。该质粒免疫小鼠后可诱导高水平的抗体,特异性淋巴细胞增殖反应、IFN-γ水平及CTL活性均明显高于空载体和生理盐水对照组。结论已成功构建HCV多表位基因的真核表达载体pcDNA3.1(-)-CtEm,免疫小鼠后可诱导特异性体液免疫和细胞免疫应答。

Construction and Immunogenicity of Recombinant Plasmid Carrying Multiepitope Gene of Hepatitis C Virus

Objective To construct a eukaryotic expression vector of hepatitis C virus(HCV) multiepitope gene and study its immunogencity.Methods Digest prokaryotic expression vector pQE30-CtEm carrying the mimic epitopes at C and E2 domains and the tandem epitope at NS3-NS5 domain of HCV with BamH I and Hind III,and insert the obtained HCV multiepitope gene CtEm into eukaryotic expression vector pcDNA3.1(-).Transiently transfect CHO cells with the constructed recombinant plasmid in mediation of liposome and determine the expression of HCV multiepitope antigen.Immunize BALB/c mice with 100 μg of the constructed recombinant plasmid and determine the humoral and cellular immune responses.Results The constructed recombinant plasmid pcDNA3.1(-)-CtEm was successfully expressed in CHO cells and induced high antibody levels in mice.The specific lymphocyte proliferation level,IFN-γ and CTL activity of mice immunized with the constructed recombinant plasmid were significantly higher than those with empty vector or physiological saline.Conclusion The eukaryotic expression vector pcDNA3.1(-)-CtEm of HCV multiepitope gene was successfully constructed and induced specific humoral and cellular immune responses in mice.