单纯疱疹Ⅱ型病毒UL29基因shRNA表达载体的干扰效应

The interference effects on UL29 shRNA expression vectors on HSV-2

目的:应用RNA干扰技术,针对单纯疱疹Ⅱ型病毒(HSV-2)UL29基因构建短发夹RNA重组表达载体,观察其对HSV-2的干扰效应。方法:针对HSV-2 UL29基因筛选出4条拟干扰靶位点序列,分别设计、合成4组靶向UL29基因shRNA的基因真核表达载体。通过脂质体转染到HEK293细胞。再将HSV-2接种到HEK293细胞中。采用终点滴定法检测病毒滴度,RT-PCR检测shRNA对转录水平的影响,Western-blot检测shRNA对蛋白质表达水平的影响。结果:终点滴定法结果显示UL29shRNA各组均可不同程度降低病毒感染滴度,与空白组(未转染重组表达载体)比较差异显著(P<0.01)。RT-PCR结果显示,与空白组比较,4组抑制率分别为28.80%、59.95%、66.08%、36.27%,差异均具有显著性(P<0.05),shRNANC(不针对任何基因的序列)与空白组相比差异无显著性,其中以UL29shRNA1461组效果为最佳。Western-blot检测表明UL29shRNA各组ICP8蛋白表达水平比阴性对照组明显降低。结论:UL29shRNA能有效干扰HSV-2UL29基因的表达,抑制HSV-2在HEK293细胞中的复制。

Objective To construct short hairpin RNA （shRNA） recombinant expression vector for herpes simplex virus type ]] （HSV-2） UL29 gene and observe its inhibitory effect on HSV-2. Methods Four interference target sites of HSV-2UL29 gene were selected to construct 4 groups of small hairpin RNA respectively, named shRNA recombinant expression vector. The expression vectors were transfected into HEK293 cells with liposome. HEK293 cells were infected with HSV-2 after expression vector being transfected. The viral titer was estimated by end-point titration assay. The level of transcription was estimated by Real-Time PCR method. The expressing effect of protein was detected by Western-blot. Results Recombinant expression vector pGPU6/GFP/Neo-shRNA was constructed successfully. The result of end-point titration assay showed that the viral titer was reduced comparing with blank control （P 〈 0.05）. The result of RT-PCR showed that inhibition rates were respectively 28.80%, 59.95%, 66.08% and 36.27% comparing with blank control, and there were significant differences （P 〈 0.05）. The effect of UL29shRNA1461 group was the best one. The result of Western-blot showed that the expressing quantity of ICP8 was reduced. Conclusion Recombinant expression vector pGPU6/GFP/Neo-shRNA can interfere HSV-2 UL29 gene expression from different cell level in vitro, which can inhibit the replication of HSV-2 genome in HEK293 cells. Thus, RNA interference （RNAi） is conducive to the further exploration of viral therapy.