SARS病毒N蛋白真核表达质粒构建及诱导的体液免疫

目的构建SARS病毒核衣壳蛋白（N）的真核表达质粒，并研究其在小鼠体内诱导的体液免疫应答。方法采用PCR方法体外扩增SARS病毒N蛋白基因片段，定向克隆入真核表达栽体pVAC，构建pVAC-N重组质粒；大量制备该重组质粒，经基因枪腹部皮内注射免疫BALB／c小鼠三次，间接ELISA法测定免疫鼠IgG抗体效价。结果成功构建了重组表达质粒pVAC-N，免疫小鼠后可诱导产生出特异性的IgG抗体。结论构建的真核表达质粒pVAC-N能诱导小鼠产生特异性抗体，为SARS疫苗的进一步研究打下基础。

Construction of eukaryotic expression plasmid of SARS coranavirus N gene and the humoral response induced by the DNA vaccine

Objective To construct a recombinant eukaryotic expression plasmid containing SARS - CoV N gene and observe the humoral immunity in mice immunized with the plasmid. Methods The specific fragment of N gene was amplified by PCR. Then, the amplified fragment was sub - cloned into pVAC expression vector. Plasmid DNA, pVAC and pVAC - N, was prepared in large quantity. BALB/c mice were used to be inoculated DNA by gene gun injection. Four weeks after the third immunization, Sera were isolated from the experimental mice, and were used to detect the titers of IgG antibody by ELISA. Results A recombinant plasmid pVAC - N was constructed which could induce specific IgG antibody in mice. Conclusion Vaccinated mice with pVAC - N recombinant could elicit the humoral immunity in mice which lay a foundation of further study on the vaccine development of SARS.