长春市HIV感染者病毒基因亚型分布状况及CRF01_AE毒株基因特征

Distribution of HIV subtypes and genic characteristics of CRF01_AE strain among HIV-positive persons in Changchun city

目的了解长春市艾滋病病毒（HIV）感染者病毒基因亚型分布状况及当前主要流行株CRF01_AE毒株的基因变异特征。方法采集HIV感染者血液标本,提取病毒核糖核酸（RNA）,应用巢式聚合酶链反应对HIV的gag区（HXB2：863~1486）基因进行扩增并测序。PhyML3.0软件构建系统进化树,采用HIV database数据库中Entropy、N-Glycosite、VESPA对CRF01_AE毒株两个独立进化簇的氨基酸多态性、糖基化位点、特征性氨基酸进行分析。结果成功测得gag序列的97例感染者中,经男男同性传播感染者71例（73.2%）;经异性传播感染者13例（13.4%）,双向传播感染者1例,12例感染途径未知。基因亚型分析结果显示,CRF01_AE 73例（75.3%）,CRF07-BC 18例（18.6%）,B亚型5例（5.2%）。URFs1例（0.1%）。系统进化树显示CRF01_AE在感染者中形成两个独立的进化簇,其中簇Ⅰ44株（61.1%）,簇Ⅱ28株（38.9%）。进一步对CRF01_AE两个进化簇分析显示：这两个独立进化簇有10个特征性氨基酸存在差异,簇Ⅰ糖基化位点多态性大于簇Ⅱ,但氨基酸位点多态性小于簇Ⅱ。结论长春市HIV感染者主要以男男同性接触感染为主,CRF01_AE已成为本地最主要流行株。CRF01_AE毒株流行簇Ⅰ和Ⅱ存在特征性氨基酸,糖基化位点和氨基酸位点存在多态性差异,提示应密切关注本地区HIV的基因变异特征。

Objective To investigate the distribution of HIV subtypes among HIV-infected persons in Changchun city and analyze the genetic variation of CRF01_AE strain.Methods The HIV gag gene region（HXB2：863-1486）was amplified and sequenced by nested polymerase chain reaction（PCR）.PhyML3.0 software was used to construct phylogenetic tree.The amino acid polymorphisms,glycosylation sites and characteristic amino acids of two independent evolution clusters of CRF01_AE were analyzed by Entropy,N-Glyco site and VESPA online program in HIV database.Results Among the 97 infected patients with gag sequence obtained successfully,71 cases（73.2%）were infected through homosexual transmission;13（13.4%）by heterosexual transmission;1 patient by bi-directional transmission,and 12 cases of infection was unknown.The gene subtype analysis showed 73 cases of CRF01_AE（75.3%）,18 of CRF07-BC（18.6%）,5 of B subtype（5.2%）,and 1 of URFs（0.1%）.Phylogenetic tree showed that CRF01_AE formed two independent evolution clusters（I-II）in the infected people with 61.1% of clusterⅠ44,and 38.4% of clusterⅡ28.Further analysis of the two independent evolution clusters of CRF01_AE showed that there were 10 characteristic amino acids difference.The polymorphism of clusterⅠwas greater than that of clusterⅡ,but the polymorphism of amino acid was less than that of clusterⅡ.Conclusion HIV infection is mainly through homosexual transmission in Changchun,with CRF01_AE as the dominant HIV strains.There are differences in the characteristic amino acid,glycosylation site and amino acid polymorphism of CRF01_AE strains,suggesting that close attention should be paid to the genetic variation of HIV in the region.