上海地区Ⅱ、Ⅲ型丙型肝炎病毒包膜区cDNA序列分析

Sequence analysis of E1,E2/NS1 region of genotype Ⅱ and Ⅲ hepatitis C virus isolated from Shanghai patients

目的 分析上海地区丙型肝炎病毒 (hepatitisCvirus ,HCV)Ⅱ、Ⅲ型包膜区cDNA序列变异。方法 采用逆转录 聚合酶链反应 (RT PCR)扩增HCV包膜区E1、E2 /NS1片断 (10 0 5bp) ,在373DNA全自动测序仪上进行了序列分析。结果 HCV E1、E2 /NS1区核苷酸和氨基酸同源性比较显示 :上海株Ⅱ型、Ⅲ型间同源性分别为 6 2 .48%和 5 9.10 % ;上海株与国内外同型株间分别为85 .97%～ 87.36 %和 83.38%～ 86 .5 7% ;上海株与国内外不同型株间分别为 6 1.49%～ 70 .95 %和5 9 .10 %～ 78.2 1%。此外 ,共发现 5个变异较大的区域 ,其中两个是国际公认的高变区 (HVR1及HVR2 ) ,另外 3个为首次报道 (第 2 5 1～ 2 5 8、2 97～ 30 1、46 1～ 46 7位氨基酸 )。结论 HCV E1、E2 /NS1序列变异大 。

Objective To analyse the variation of envelope gene of genotype Ⅱ and Ⅲ hepatitis C virus (HCV) isolated from Shanghai patients with chronic hepatitis C. Methods The envelope genes (E1, E2/NS1) were amplified by nested reverse transcription polymerase chain reaction (RT PCR). Totally 1 005 bp were sequenced and compared with previously reported isolates. Results The nucleotide (nt) and amino acid (aa) homologies between genotype Ⅱ and Ⅲ Shanghai isolates were 62.48% and 59.10%, respectively. The nt and aa homologies between Shanghai isolates and isolates with the same genotype from different regions were 85.97%～87.36% and 83.38%～86.57%, whereas the homologies between isolates with different genotypes, were 61.49%～70.95% and 59.10%～78.21%. Five hypervariable regions (aa 251～258, 297～301, 384～408, 461～467, 475～480) were found and two of them were consistent with the two hepervariable regions reported previously (aa 384～408, 474～482). Conclusion The variation of envelope gene was great and the knowledge of how variability distributed along different regions of the HCV genome could be helpful in the design of HCV vaccine.