真核化的原核表达系统增强HBV preS2/S基因免疫的效果

目的：研究真核化的原核表达系统——pCMV-T7poL／pT7IRES-HBs双质粒共表达体系与常规真核表达质粒相比在真核细胞中的表达差异；基因免疫小鼠诱生特异性体液免疫应答的能力及二者所诱生的抗体亚型的差异。方法：运用分子生物学方法构建真核化的原核表达系统，将构建的质粒进行基因免疫，应用DOT-EIA和ELISA等检测其所产生的抗体水平。结果：①真核化的原核表达系统在真核细胞中的表达能力明显强于常规真核表达质粒。②真核化的原核表达系统基因免疫小鼠不仅可诱生特异性体液免疫应答，且具有明显增强效应（P〈0．05）。③真核化的原核表达系统与常规真核表达质粒相比不仅可诱生同等程度的Th1型免疫应答，而且能够诱生更强的Th2型免疫应答（P〈0．01）。结论：真核化的原核表达系统——pCMV-T7pol／pT7IRES-HBs双质粒能诱导较强的体液免疫应答。

Enhancing effect of eukaryonized prokaryotic expression system on HBV preS2/S gene immunization

Objective:To investigate the difference of expression level between classical eukaryotic expression system and eukaryonized prokaryotic expression system made of pCMV-T7pol and pT7IRES-HBs in eukaryotic cell environment.Methods:Eukaryonized prokaryotic expression plasmid was constructed and gene immunize was conducted with these plasmid;the antibody induced by these plasmid was evaluated by DOT-EIA and ELISA.Results:It was demonstrated that the eukaryonized prokaryotic expression system could efficiently enhance the expression level of target gene in eukaryotic cells. To further investigate the ability of eukaryonized prokaryotic expression system to induce HBV specific humoral immune response, mice were intramuscularly immunized with the mixture of the plasmid pCMV-T7pol and the plasmid pT7IRES-HBs. It was demonstrated that HBV specific humoral response not only could be induced, but also was much stronger than that induced by the classical eukaryotic expression system. And the HBV specific Th2 type immune response was greatly enhanced(P<0.01).Conclusion:Eukaryonized prokaryotic expression system could induce stronger humoral response in vivo.