广西HIV-1重组流行株env基因V3-V4区序列变异分析

SEQUENCE ANALYSIS ON THE GENETIC VARIATIONS OF V3-V4 REGION OF ENV GENE FROM THE CIRCULATING RECOMBINANT FORM OF HIV-1 IN GUANGXI

[目的]分析广西HIV-1重组流行株env基因V3-V4区及其临近区域的基因变异。[方法]应用nest-PCR对24份来自广西主要流行区的HIV-1重组毒株env基因区进行扩增后,使用ABI310型测序仪测序,然后应用CLUSTAL、MEGA和dnatools等生物学软件对env基因区V3-V4区及其临近区域进行序列分析。[结果]24份毒株中21份为CRF01-AE(93.48%),3份为CRF08-BC(6.52%);系统树分析显示,21份与分离于广西地区的CRF01-AE.97CNGX2f和泰国代表毒株THCM240接近,3份CRF08-BC重组毒株中有2份与CRF08-BC.98CN006和CRF08-BC.97CNGX6f靠近,还有1份样本则接近C.95IN21068;env基因V3-V4区核苷酸序列分析显示,广西的样本与分离于该地区的代表毒株基因距离较小,CRF01-AE和CRF08-BC重组毒株的氨基酸替换主要发生在C3和V4区,而V3区氨基酸序列相对保守。[结论]CRF01-AE重组毒株env基因V3-V4区的变异主要发生在C3和V4区,而不是V3区。

[Objective] To study the genetic variations of V3-V4 and flanking regions of the env gene from the circulating recombinant form （CRF） of human immunodefieiency virus type 1 （HIV-1） in Guangxi. [Methods] 24 samples were collected from the prevailing area of HIV-1 in Guangxi. Fragments of the HIV-1 env gene were amplified by nest-PCR from proviral-DNA templates of HIV-1 infected individuals. The PCR products were then directly sequenced by using ABI 310 DNA SEQUENCER. The sequencesof V3-V4 region and flanking region of the env gene from CRF were carried out amino acid mutations by CLUSTAL. MEGA and dnatools software. [ Results] Of the 24 samples, 21 samples （ 87.5% ） were infected with CRF01-AE. 3 （12.5%） were infected with CRF08-BC. Phylogenetic tree analysis showed that 21 CRF01-AE strains clustered with 97CNGX2F andTHCM240, while 2 CRF08-BC strains were closely related to CRF08-BC.98CN006 and CRF08-BC. 97CNGX6f, and 1 CRF08-BC clustered with C.95IN21068. Nueleotied sequence analysis showed that DNA distances in V3-V4 regions of the env gene of 24 samples were closely related to the normal strains in Guangxi, and majority of amino acid substitution occurred in C3 and V4 regions rather than V3 region. [Conclusions] Majority of genetric variation in V3-V4 regions of the env gene from recombinant form of CRF01-AE occur in the C3 and V4 regions rather than V3 region.