广州市男男性行为HIV-1感染者主要流行株GP120序列变异分析

Analysis on variation characteristics of HIV-1 Gp120 sequences in men who have sex with men in Guangzhou

目的 了解广州市男男性行为HIV-1主要流行株Gp120基因的序列特征.方法 收集广州市男男性行为HIV-1感染者抗病毒治疗前血浆,提取病毒RNA,反转录巢式PCR扩增获得HIV-1膜基因Gp120全长,对获得的序列进行系统进化树、长度多态性、V3环氨基酸、辅助受体预测及特征性氨基酸分析.结果 61例样本分为4个亚型,主要流行株为CRF07 BC(34/61,55.74%)和CRF01 AE亚型(24/61,39.34%).主要流行株Gp120序列长度为496~515个氨基酸,V1和V3高变区分别表现出最高和最低的长度多态性.主要流行株V3环顶端四肽的主要形式为GPGQ(56/58,96.55%),4种方法综合预测主要流行株的辅助受体主要为CCR5(50/58,86.21%).广州市男男性行为HIV-1感染者中流行的CRF01 AE亚型毒株存在4个特征性氨基酸,出现频率为0.75~0.83,CRF07 BC亚型毒株存在8个特征性氨基酸,出现频率为0.74~0.94.结论 广州市男男性行为HIV-1感染者主要流行株Gp120序列长度有着较高的多态性,V3环顶端四肽、辅助受体和特征性氨基酸有其自身特点.

Objective To analyze the variation characteristics of HIV-1 Gp120 sequences in men who have sex with men ( MSM) in Guangzhou. Methods Plasma samples were collected from HIV-1 infected MSM before antiretroviral treatment. Viral RNA was extracted from plasma. Gp120 gene sequences were amplified by reverse transcription and nested-PCR using specific primers. Phylogenetic tree, length polymorphism, amino acid characteristics of V3 loop, co-receptors and signature amino acids were analyzed. Results The phylogenetic tree were divided into 4 clusters, and the most prevalent subtypes were CRF07 BC ( 34/61,55. 74%) and CRF01 AE ( 24/61,39. 34%) . Majority of HIV-1 Gp120 sequences had 496-515 amino acids. Among five hypervariable regions, the V1 region had the highest levels of length polymorphism and V3 region had the lowest. The top four peptide of V3 loop were GPGQ (56/58, 96. 55%). Most of the co-receptors HIV-1 strains used was CCR5 ( 50/58, 86. 21%) according to four methods of comprehensive prediction. There are four signature amino acids in CRF01 AE subtype strains, and the frequency of occurrence was 0. 75-0. 83;there are eight signature amino acids in CRF07 BC subtype strains, and the frequency was 0. 74-0. 94. Conclusions The length of Gp120 sequences in MSM in Guangzhou has a high polymorphism. The top four peptide of V3 loop, co-receptor and signature amino acid of V3 ring have formed unique patterns.