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

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CBF01-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：CPCQ、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。

The potential relationship between variation of V3 loop in CRF01-AE strains of HIV type 1 from Guangxi and virus biological phenotype

Objective To study the potential relationship between genetic variation in the V3 and it's flanking regions of the ens gene in CRP01-AE strains of human immunodeficiency virus type 1 (HIV-1) in Guangri and virus biological phenotype. Methods DNA was extracted from 50 blood samples in the prevalent area of Guangri. 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 HTV-1 subtype CRF01-AE strains were selected for establishing phylogenetic trees and analyzing amino acid mutations. Results Phylogenetic tree analysis showed that 36 CRP01-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 potential use of coreceptors 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 currendy circulating in Guangxi is likely to be non-syneytium inducing (NSI).