密码子优化对鸭坦布苏病毒E基因DNA疫苗免疫应答的增强作用

Optimization of codon usage of E gene enhanced immune responses of DNA vaccine against duck Tembusu virus

为提高DNA疫苗用于预防鸭坦布苏病毒病的免疫原性,将鸭坦布苏病毒的E基因密码子改造为鸭偏嗜的密码子,并将其作为免疫原基因克隆到pCAGGS载体中,构建真核表达质粒pCAGGS-OptiE。将pCAGGS-OptiE和先前构建的编码野生型E基因的表达质粒pCAGGS-E分别转染293T细胞,用间接免疫荧光和Western-blot检测E蛋白的表达情况。结果显示,密码子优化的重组质粒的蛋白表达量明显高于野生型质粒。将重组质粒pCAGGS-OptiE和pCAGGS-E用脂质体包裹后分别尾静脉注射免疫BALB/c小鼠,采用间接ELISA检测抗体的产生情况。结果显示,质粒pCAGGS-OptiE诱导的抗体水平明显高于pCAGGS-E,表明密码子优化的E基因能够提高蛋白的表达水平,进而增强机体免疫应答反应。

To improve the immunogenicity of DNA vaccines,E gene of duck Tembusu virus（DTMUV）was optimized according to the codon bias of duck.The optimized E gene（OptiE） and the wild-type E gene were cloned into the pCAGGS vector to generate the pCAGGS-OptiE and pCAGGS-E vectors,respectively.The E protein transiently expressed in the 293T cells was detected by indirect immunofluorescence assay and Western-blot.Results showed that the expression of optiE protein in vitro was increased in comparison to that of the wild-type.The immunogenicity of two constructs wrapped by liposomes was then evaluated in BALB/c mice with the antibodies detected by indirect ELISA.Results showed that the antibody level induced by pCAGGS-OptiE was higher than that did by pCAGGS-E.These results indicated that the codon optimization of E gene enhanced the immune efficacy of the DNA vaccine against DTMUV.