【摘要】 目的研究我所发现的丙型肝炎病毒(HCV)1b基因型5′非编码区(5′NCR)222位C-T变异的病毒株,是否为1型中的其他亚型。方法对64例HCV1b型的样本进行5′NCR扩增后作BamHI酶切,并从有此BamHⅠ位点的样品中随机选取了6例样品扩增5′NCR和NS5B区,测序后对5′NCR进行序列分析,NS5B区序列分别与GenBank中1型的各亚型序列以及38株来自世界不同地区的1b型参考序列构建遗传进化树。结果6例样本与GenBank中1型的各亚型NS5B区遗传进化树分析结果显示这6株都属于1b型,而非1型的其他亚型,6株变异株与38株来自世界不同地区的1b型参考序列NS5B区的进化树分析结果显示,6例样品并未形成1b型中的独立分支,在遗传进化上与其他38株HCV1b型病毒株没有明显差异。结论本文的研究证实了我们所发现的HCV1b型5′非编码区有BamHⅠ位点的病毒株确为1b型的变异株,并非1型的其他亚型。而这种变异与干扰素耐药是否具有相关性,尚有待于进一步研究。更多还原

【Abstract】 Objectives In our studies before, we reported mutation C-T at -222 of hepatitis C virus type 1b genotyped on 5′ noncoding region (5′NCR). There was no this mutation of type 1b recorded in GenBank. Since genotypiog based on 5′NCR cannot differentiate subtypes, it is necessary to investigate whether the hepatitis C virus genotype 1b strains with mutation C-T belongs to other subtypes of genotype 1. Methods 64 HCV genotype 1b samples were amplified from 5′NCR by RT-PCR.Then the products were digested by use of BamHⅠ restriction enzymes. We randomly chose 6 samples with BamHⅠ restriction site and subjected them to amplification of 5′NCR and NS5B. The sequences of 5′NCR were analyzed. Sequences of NS5B fragments from the 6 samples were respectively subjected to phylogenetic analysis with subtypes of genotype 1 and 38 complete genomes of genotype 1b from GenBank.Results The phylogenetic analysis of 6 samples and subtypes of genotype 1 indicated that the genotypes of 6 strains with BamHⅠ restriction site in 5′NCR were type 1b, instead of subtype of type 1. Tree construction with 38 complete genomes of genotype 1b showed that the 6 mutants of genotype 1b did not belong to the same branch of the tree and there were no genetic differences between the mutants and the other strains of genotype 1b.Conclusions Our research indicated that the hepatitis C virus stains of C-T in 5′NCR were mutants of type 1b. Since the 5′NCR is a highly conserved region of HCV, the mutation might have some relationship to the long-time IFN therapy.更多还原