新型呼肠病毒 S基因 DNA 疫苗在小鼠体内的免疫原性

目的：探讨新型呼肠病毒R4株S片段免疫小鼠后引发的免疫应答。方法构建4个不同S基因节段的重组真核表达质粒，并免疫小鼠；ELISA检测血清以研究R4特异性抗体升高水平，并对其抗体亚型进行鉴定；ELISPOT检测小鼠淋巴细胞INF-γ的表达情况。结果与对照组相比，4个重组质粒免疫的小鼠血清都有明显的R4特异性抗体升高，尤其以S1和S3基因免疫后抗体水平较高，且均以IgG2a占绝对优势；S1基因免疫组小鼠的细胞免疫应答最强。结论 S1基因重组质粒免疫小鼠后可同时引发较强的体液免疫和细胞免疫应答，是较为理想的疫苗备选基因片段。

Immunogenicity of a vaccine of S fragments from a new type reovirus generates humoral and cellular immune responses in mice

Objective To explore the humoral and cellular immune responses of a vaccine of S fragments from a new type reovirus R4 strain in mice.Methods Four recombinant plasmids were constructed by respectively cloning S 1, S2, S3,S4 genes into pcDNA3.1＋, and mice were intramuscularly immunized with the recombinant plasmids in a dose of 100 μg/mouse.Control vector pcDNA3.1 ＋and phosphate buffered saline （PBS） were used as negative controls.The spe-cific antibody level and IgG subclass （IgG1, IgG2a, and IgG2b） were detected by ELISA, and cellular immune responses to R4 were assessed using an interferon （ IFN）-γELISpot assay .Results All recombinant plasmids induced significantly higher levels of anti-R4 IgG compared with that of the controls （pcDNA3.1 ＋and PBS）, and the titers were highest in the mice immunized with S1 and S3.On the other hand, S1 gene induced highest IgG2a antibody and the cellular immune re-sponse was best .Conclusions After the mice immunized with S 1 gene recombinant plasmid , this plasmid can initiate both cellular and humoral immune responses in mice .S1 gene recombinant plasmid is a promising vaccine candidate .