丙型肝炎病毒功能基因在CHO细胞中的表达研究

Expression and Study of the Functional Proteins of Hepatitis C Virus in CHO Cell Line

摘要:

丙型肝炎病毒（HCV）与宿主细胞因子的相互作用已经成为国内外研究的热点和难点。近期研究已经证实HCV的感染对宿主多种途径中基因的转录均能产生影响。为了进一步研究究竟是HCV中的哪些功能基因在与特定细胞因子的相互作用中起主导作用，构建了分别含有HCV Core、E1、E2、p7、NS2、NS3、NS4A、NS4B、NS5A和NS5B基因的真核表达质粒，分别转入宿主细胞CHO-K1中，在G418的选择压力下筛选获得稳定表达HCV单个蛋白的细胞系（10株）。PCR和RT-PCR可分别从稳定细胞系中检测到相应的HCV基因的DNA和mRNA，冻存和复苏不会造成HCV基因的丢失。Western-blot检测到稳定细胞系中表达E1，E2和NS5B蛋白，说明HCV基因在CHO-K1中已经形成稳定表达。薄层层析（TLC）结果显示，含有不同HCV基因的稳定传代细胞系中，UDP-葡萄糖神经酰胺葡萄糖基转移酶（UGCG）活性均发生了不同程度的变化，其中E2和p7的表达使胞内UGCG的活性提高了约1倍，NS2和NS5A则使UGCG的酶活提高了约0.6倍。该稳定细胞系的建立为研究病毒与宿主因子的相互作用及药物筛选奠定了基础。

Abstract:

Recently，the interactions between hepatitis C virus (HCV) genes and the host cell factors were the focus of this field. Cell factors in the different biochemical pathway were approved to be interfered when HCV infection. To make sure which HCV gene(s) was the major factor during the interaction process，ten eukaryotic expression plasmids containing different functional genes of HCV: Core，E1，E2，p7，NS2，NS3，NS4A，NS4B，NS5A and NS5B were transfected into the CHO-K1 cells respectively. Then ten stable cell lines expressing different HCV functional proteins were constructed under the selective pressure of G418. DNA and mRNA of the HCV genes were both detected by PCR and RT-PCR respectively in the corresponding stable cell lines，freezation and anabiosis would not lose the HCV genes. Besides，the E1，E2 and NS5B proteins were detected by Western-blot which demonstrated that the HCV genes have formed stable expression in the host cells. The activity of UDP-glucose ceramide glucosyltransferase (UGCG) in the stable cell lines increased in different degree by TLC assay. For example，the activity of UGCG in CHO-K1-E2 and CHO-K1-p7 was doubled according to the control cells，and in CHO-K1-NS2 and CHO-K1-NS5A was about 1.6 times compared with the control cells. The establishment of the stable cell lines containing different single HCV gene will provide foundation for investigating the interactions between the virus and the host factors，and for the filtration of antiviral medicine.