长期不进展人类免疫缺陷病毒-1感染者准种膜蛋白V3环氨基酸特点分析

Characteristics of amino acid sequences of envelop protein V3 loop of human immunodeficiency virus type 1 quasi-species in long-term non-progressors infected with human immunodeficiency virus type 1

目的 了解长期不进展HIV-1感染者HIV-1准种膜蛋白V3环氨基酸序列特征及变异特点.方法 应用终点有限稀释套式PCR方法,对5例长期不进展HIV-1感染者不同时间点单个HIV-1前病毒env基因c2-v3-c3区域进行扩增和序列测定,用序列确证分析技术分析env基因区V3环氨基酸序列特征.结果 5例患者不同随访时间点获得的准种序列中,V3环35个氨基酸中出现多样性的位点分别有1～10个不等,同一患者不同随访时间点准种优势株序列完全一致或仅有1～2个位点不同;4例患者V3环顶端四肽为GPGR,1例患者为GPGK,同一患者不同随访时间点V3环顶端四肽一致;根据V3环11和25位氨基酸及V3环的电荷推测HIV-1辅助受体均为趋化因子受体（CCR）5.结论 长期不进展HIV-1感染者V3环序列存在不同程度变异,顶端四肽稳定性高,感染的HIV-1毒株可能为非合胞体诱导型毒株.

Objective To investigate the characteristics of V3 loop amino acid sequences of human immunodeficiency virus type 1 （HIV-1） quasi-species in long-term non-progressors （LTNP）infected with HIV. Methods End-point limiting dilution polymerase chain reaction （EPLD PCR） was used to amplify the env gene c2-v3-c3 region of single HIV-1 provirus from five LTNPs at sequential time points. The PCR products were then sequenced and the amino acid sequences of V3 loop were analyzed by sequence confirm analysis technology. Results The results showed that there were one to ten kinds of polymorphisms in the V3 region of HIV-1 quasi-species which were found from the serial samples of the five LTNP. However, the sequences of the predominant strains were either completely consistent or at most changed at one or two residues in the serial samples of individual patient. The tetramer compositions of the tip of V3 loop were consistent in each patient. It was GPGR in four patients and GPGK in one patient. It was speculated the co-receptor of HIV-1 was CC chemokine receptor （CCR）-5 based on the amino acids at the residue 11 and residue 25 of V3 loop and the net charge of V3 loop. Conclusions There are various polymorphisms at the HIV V3 loop in LTNP. However, the tetramer composition of the tip part of V3 loop is stable. The LTNP are very likely infected with non-syncytium inducing （NSI） strain.