HIV-1早期感染婴儿病毒亚型及env区V3环氨基酸特征分析

目的分析中国I型艾滋病病毒（HIV-1）感染婴儿基因亚型的分布情况,以及env区V3环氨基酸序列特征。方法利用巢式聚合酶链反应（nPCR）扩增HIV-1前病毒脱氧核糖核酸（DNA）env区和pol区的基因序列,使用ChromasPro、MEGA 4.0、BioEdit软件进行HIV-1基因分型以及env区V3环氨基酸序列的特征分析。结果对65名HIV-1感染婴儿的100份干血斑样本（DBS）分别进行HIV-1 env区和pol区扩增,最终扩增成功的样本为63份和84份;其中45名感染婴儿的59份DBS两基因区均扩增成功。依据两基因区域均扩增成功的45名感染婴儿样本进行基因分型,结果为：CRF_BC亚型占73.3%（33/45,包括CRF_07-BC 21份,CRF_BC-08 11份）,CRF01-AE亚型占20.0%（9/45）,B′亚型占4.4%（2/45）,G亚型占2.2%（1/45）。对env区扩增成功的63份样本的V3环顶端四肽特征序列进行分析,结果显示存在5种类型,分别为GPGQ、GPGR、GPGS、GLGR和GQGR,以GPGQ为主。53份样本可能使用CCR5作为辅助受体,3份样本可能使用CXCR4作为辅助受体,7份样本不能做出预测。结论婴儿感染的HIV-1亚型呈现多样性分布;HIV-1V3环顶端氨基酸序列以GPGQ为主;大部分婴儿样本可能使用CCR5作为辅助受体。

Study of HIV-1 genotyping and the characteristics of amino acid V3 loop of env gene in HIV-1 infected infants

Objective To analyze subtypes of human immunodeficiency virus type I （HIV-1）of infected infants and the characteristics of amino acid V3 loop of env gene. Methods HIV-1 proviral deoxyribonucleic acid （DNA） was amplified through nested-polymerase chain reaction （nPCR）, the env gene and pol gene were sequenced and ChromasPro , MEGA 4 , BioEdit software were used to subtyping and analyzing env gene V3 loop amino acid sequences. Results Sixty three env gene and 84 pol gene were amplified and sequenced successfully from 100 dried blood spots（DBS）samples from 65 infected infants. Of which 59 samples from 45 infants were sequenced successfully in both env gene and pol gene. Subtyping were made based on the successfully amplified samples of 45 infants in two genes, the results were： 73.3% CRF BC（33/45,of which 21 were CRF 07-BC,11 were CRF BC-08）, CRF01-AE 20.0% （9/45）, subtype B′4.4% （2/45）, subtype G 2.2% （1/45）. The characteristics polypeptide of V3 loop contains： GPGQ, GPGR, GPGS, GLGR, GQGR. In all 63 env gene successfully sequenced samples, 53 samples might use CCR5 as coreceptor, 3 samples might use CXCR4 as coreceptor, and 7samples cannot be predicted. Conclusion HIV-1 subtype shows diversified distribution in infants. GPGQ is the dominant amino acid of HIV-1 V3 loop, and most of samples of infected infants use CCR5 co-receptor to enter into CD4 cells.