传染性支气管炎病毒S1蛋白在Vero细胞的表达与分布

Expression and distribution of S1 protein of infectious bronchitis virus in Vero cells

将传染性支气管炎病毒(IBV)ZJ971 S1基因亚克隆到绿色荧光蛋白(GFP)表达载体pEGFP-C2中,成功构建重组表达质粒pEGFP-ZJ971-S1。重组质粒在脂质体的介导下转染Vero细胞,借助荧光显微镜在转染后4h观察到S1-GFP融合蛋白的瞬时表达。免疫细胞化学染色(ICC)结果显示,抗ZJ971 S1D蛋白单克隆抗体和鸡抗IBV ZJ971全病毒血清特异性识别了S1基因转染细胞,表明S1蛋白在Vero细胞中得到有效表达。荧光显微镜观察和ICC均表明,S1表达蛋白主要分布在转染细胞的胞浆内,而胞核中未见分布,提示IBV S1蛋白内可能存在与病毒装配相关的细胞定位信号。

S1 gene of infectious bronchitis virus （IBV） strain Z J971 was subcloned into an expression vector pEGFP-C2 carrying GFP reporter gene and a recombinant plasmid, designated as pEGFP-ZJ971-S1, was successfully constructed. Vero cells were transfected with the recombinant plasmid by liposome and finally S1-GFP fusion protein was transiently expressed 4 h post-tranfection. Immunocytochemical staining showed that monoclonal antibodies against IBV ZJ971 S1 protein and chick anti-IEV serum specifically recognized S1 protein expressed in Vero cells. Fluorescence observation for Vero cells expressing GFP-fused S1 protein and ICC both confirmed that the S1-GFP was found to mainly distribute in the cytoplasma but not in the nucleus of Sl-transfected Vero cells, suggesting that intracellular targeting signal involved in viral assembly may exist within IBV S1 protein.