Ubiquitin基因介导下的PRRSV GP5基因免疫特性研究

Immune responses induced by DNA vaccination of ubiquitin-conjugated GP5 protein gene of porcine respiratory and reproductive syndrome virus

泛素—蛋白酶体途径是一种高效蛋白降解途径,主要负责真核细胞内蛋白选择性降解。GP5囊膜糖蛋白是PRRSV的主要结构蛋白。为了评价泛素基因对GP5基因免疫的影响,本研究将ORF5 DNA片段克隆到含泛素(Ub)基因的表达载体pCMV-Ub和pcMV载体,构建成重组质粒pCMV-Ub-GP5和pCMV-GP5。两种质粒DNA肌肉注射免疫BALb/c小鼠后,分别检测体液免疫反应和特异的细胞免疫反应,比较单基因和融合基因DNA免疫所诱生免疫应答的强度。结果表明二者均可诱生抗体的效率无明显差别,但泛素的融合使得针对GP5的特异性细胞免疫反应明显增强。

The ubiquitin-proteasome pathway is an efficient pathway for protein degradation.It＇s mainly responsible for the selective degradation of many proteins in eukaryotic cells.In order to evaluate the immunity of GP5 protein gene of porcine respiratory and reproductive syndrome virus （PRRSV）,the GP5 protein gene was amplified with PCR and cloned into both pCMV-Ub and pCMV plasmid,respectively,and two recombinant plasmids,pCMV-Ub-GP5 and pCMV-GP5,were constructed and identified.Mice were immunized with the two kinds of plasmids.The serum antibodies and cellular immune response of mice were detected.The results showed that there were not much more differences between the two plasmids in antibody responses,but the fusion gene DNA induced stronger cellular immune responses than single gene DNA did,which indicated that Ub conjugation did improve the cellular immune response to GP5 in mice.