猪泛素基因与PRRSV GP5基因融合表达质粒的构建及其免疫效果

构建了泛素(ubiquitin,Ub)基因与密码子优化的PRRSV GP5蛋白(optiGP5)基因融合表达质粒pIR-Ub-optiGP5。间接免疫荧光和Western-blot分析表明,重组质粒转染293T细胞后能够瞬时表达。将pIR-optiGP5和pIR-Ub-optiGP5两种质粒DNA肌肉注射免疫BALB/c小鼠后,分别检测小鼠血清中抗GP5抗体、T淋巴细胞的增殖能力以及CTL活性。结果显示,pIR-optiGP5质粒免疫组在二免后可以检测到荧光抗体,而pIR-Ub-optiGP5质粒免疫组一直未检测到抗GP5抗体,但该免疫组的T淋巴细胞增殖指数及针对GP5的特异性CTL反应数值明显高于pIR-optiGP5质粒免疫组。这表明泛素与GP5的融合表达可增强细胞免疫反应。

Construction of recombinant plasmid co-expressing swine ubiquitin gene with GP5 gene of porcine reproductive and respiratory virus and analysis of its immunogenicity in mice

A kind of expression plasmid was constructed,which was integrated with fusion gene of ubiquitin and GP5-optimized codon of porcine reproductive and respiratory virus(PRRSV pIR-Ub-optiGP5).After the expression plasmid was transfected into 293T cell,the expression of GP5 gene was detected by indirect immunofluorescence assay and Western-blotting.Then,the plasmids pIR-optiGP5 and pIR-Ub-optiGP5 were used to intramuscularly immunize BALB/c mice,respectively.Serum antibodies against GPS T cell proliferation and cytotoxic T lymphocyte(CTL) response in the mice were detected.The antibody against GPS was produced in the mice immunized with pIR-optiGP5 and not produced in the mice immunized with pIR-Ub-optiGP5 post-2nd-immunization,but T cell proliferation index and CTL response value in the former were significantly higher than those in the latter.The results suggested that the co-expression of ubiquitin gene with GP5 gene can improve the cellular immune response.