广西HIV-1 CRF01-AE重组毒株env基因V3环序列变异及其与生物表型的关系

The potential relationship between variation of V3 loop in CRP01-AE strains of HIV type 1 from Guangxi and virus biological phenotype

目的研究广西HIV-1 CRF01-AE重组毒株env基因V3环序列变异及其与生物表型间的关系。方法从广西主要流行区收集来的50份HIV-1感染者血液样本中提取前病毒DNA,使用巢式聚合酶链反应(nested-PCR)扩增HIV-1 env基因片段并进行亚型鉴定,选择38份CRF01-AE重组型HIV-1毒株env基因V3环及邻近区域的序列进行系统树和氨基酸变异分析。结果38份CRF01- AE重组毒株中36份与分离于广西地区的CRF01-AE．97CNGX2f和泰国代表毒株THCM240接近,另外2份与中非共和国代表株90CF402聚成一簇;CRF01-AE重组毒株V3环顶端四肽存在着4种类型: GPGQ、GPGR、GPGH和GPGA;根据V3环关键氨基酸推测辅助受体使用情况,结果显示:71．05％的CRF01-AE重组毒株可能使用CCR5作为辅助受体,28．95％不能对其辅助受体的使用情况做出预测。结论广西HIV-1 CRF01-AE重组毒株V3顶端四肽变异较大,而且大部分毒株可能为NSI型,这可为广西该毒株的防治和诊断试剂的更新提供参考。

Objective To study the potential relationship between genetic variation in the V3 and it＇s flanking regions of the env gene in CRF01-AE stains of human immunodeficiency virus type 1 （HIV-1） in Guangxi and virus biological phenotype. Methods DNA was extracted from 50 blood samples in the prevalent area of Guangxi. Fragments of the HIV-1 env gene were amplified by nested -polymerase chain reaction （n-PCR）. The products were then directly sequenced by ABI 310 DNA sequencers. The sequences covering the env V3 and it＇s flanking regions of 38 HIV-1 subtype CRF01-AE strains were selected for establishing phylogenetic trees and analyzing amino acid mutations. Results Phylogenetic tree analysis showed that 36 CRF01-AE strains clustered with 97CNGX2F and THCM240. while the other 2 CRF01-AE were closely related to 90CF402. Analysis of deduced amino acid sequences in the V3 region of 38 samples from CRF01-AE strains demonstrated the CRF01-AE strains had four types of V3 loop central motif; GPGQ, GPGR, GPGH and GPGA. Predictions for the potertial use of coreceptore on the basis of the critical amino acids within V3 loop showed that 71.05% of the CRF01-AE strains were predicted to be CCR5-using, while 28.95% of the CRF01-AE strains could not be predicted. Conclusion The V3 loop in CRF01-AE strains are much more variable and the majority of those currently circulating in Guangxi is likely to be non-syncytium inducing （NSI）.