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

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

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。

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-UboptiGP5）. 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 coexpression of ubiquitin gene with GP5 gene can improve the cellular immune response.