中文摘要：

目的：观察基于戊型肝炎病毒中和表位（p179）的基因免疫是否能在小鼠体内诱导具有中和作用的抗体应答。方法：构建含HEV中和表位p179编码基因的真核表达质粒pVAX-179,以肌肉注射法对BALB/c小鼠实施基因免疫,实验组每只小鼠给pVAX-179 100μg,并设立空质粒pVAX和HEV-p179蛋白两个对照组。定期采集小鼠血清,ELISA法检测其特异性抗HEV-IgG抗体及其亲合力;以基于PCR的体外中和实验检测抗体的中和活性。结果：pVAX-179质粒基因免疫诱导小鼠体内产生了特异性抗-HEV-IgG抗体,抗体水平于第10周达高峰,OD值为0.55±0.13,与空质粒pVAX组（0.15±0.07）比较差异有统计学意义（P〈0.001）。第6周实验组抗体亲合力（ED50为2.5 mol·L^-1）高于蛋白对照组（ED50为2.0 mol·L^-1）,基因免疫促进了抗体亲合力的成熟;体外中和实验证实产生的特异性抗体能够阻止HEV感染人肝癌细胞7721,具有中和HEV的活性。结论：基于戊型肝炎病毒中和表位（p179）的基因疫苗pVAX-179能够在小鼠体内诱导产生具有中和作用的抗体应答。

英文摘要：

Objective：To investigate whether the DNA vaccine based on HEV neutralization epitope（s） HEV-p179 could induce neutralizing antibody response in mice.Methods：The neutralization epitope（s） HEV-p179-coding gene was subcloned into a eukaryotic expression vector pVAX to construct recombinant plasmid pVAX-179.BALB/c mice were immunized i.m.with 100 μg DNA of pVAX-p179 plasmid,mock DNA,and 1 μg protein of HEV-p179,respectively.Sera collected at the indicated times from two groups were determined the levels and avidity of specific anti-HEV IgG antibody by ELISA.The neutralizing activity of induced anti-HEV antibody was detected in a PCR-based cell culture neutralization assay.Results：Immunizations with pVAX-179 successfully induced anti-HEV specific antibody response and accelerated the avidity maturation of antibodies.The anti-HEV level reached the hightest values about 10 weeks after first vaccination.The avidity of antibodies from pVAX-179 immunized mice was higher than that from HEV-p179 protein immunized group.In addition,the post-immune sera obtained from pVAX-p179 vaccinated mice were found the protective neutralizing activity against HEV infection.Conclusion：These results indicate that the DNA vaccine based on HEV neutralization epitope（s）-HEV-p179 could induce neutralizing antibody response against HEV in mice.