中国HIV／AIDS典型进展者与疾病长期不进展者中和抗体保守表位氨基酸变异比较研究

Study on amino acids mutation of conserved neutralization epitopes of HIV/AIDS progressors and long-term nonprogressors in China

目的研究中国HIV／AIDS典型进展者及疾病长期不进展者（LTNP）中和抗体保守表位氨基酸变异，探讨中和抗体表位变异与疾病进展关系，为开展中和抗体免疫治疗和疫苗设计奠定理论基础。方法RT-PCR及巢式PCR扩增HIV／AIDS典型进展者及LTNP的HIV-1 gp120 C2-C3区基因，双脱氧终止法进行核酸序列测定，翻译为氨基酸序列，与HIV-1 Sequence Databme参考毒株比对识别中和抗体保守表位氨基酸变异。结果HIV／AIDS典型进展者CD4结合位点（CD4BS）、CD4诱导（CD4i）、2G12中和抗体保守表位氨基酸均存在变异，LTNP2G12中和抗体保守表位氨基酸存在变异；LTNP各表位突变率较典型进展的HIV感染者／AIDS患者有降低趋势，但差异无统计学意义（P〉0．05）；CD4BS、CD4i、2G12变异表位构成比分别为25．0％、22．9％、52．1％，2G12表位变异明显高于CD4BS和CD4i表位，差异有统计学意义（P〈0．01）；CD4BS和CD4i保守表位变异多见于E370Q（10．8％），2G12保守表位变异多见于N295V（18．9％）和T2971（9．5％）。结论中国HIV感染人群中，LTNP中和抗体保守表位氨基酸构成相对稳定，变异较典型进展的HIV感染者／AIDS患者少见，目前发现2G12中和抗体表位存在较低水平变异。中和抗体表位中，2G12表位变异较CD4BS和CD4i表位多见，各类型中和抗体保守表位氨基酸位点的变异程度存在差异。

Objective To study the amino acids mutation of conserved neutralization epitopes of HIV/AIDS patients and long-term nonprogressors （LTNP） in China, and to provide a basis for design of vaccine and immunotherapy with antibody. Methods RT-PCR and nest-PCR methods were used to amplify gene on HIV-1 gp120 C2-C3 region. Nucleic acids were sequenced by double-deoxygen terminal method and translated into amino acids for analysis. The mutations of conserved neutralization epitope were identified by comparison with the epitope reference data in HIV-1 Sequence Database. Results HIV/AIDS patients had conserved neutralization epitope mutation, including CD4-binding site （CD4BS）, CD4-induced （CD4i） and 2G12; LTNP group had 2G12 epitope mutation. The mutation rates had no significant difference （P 〉 0.05） among HIV/AIDS patients and LTNP. The constituent ratios of mutation epitope of CD4BS, CD4i and 2G12 were 25.0%, 22.9% and 52. 1%, respectively （P 〈0. 01 ）. CD4BS and CD4i conserved neutralization epitope mutation focused on E370Q （ 10.8% ）, 2G12 conserved neutralization epitope mutation focused on N295V（18.9% ） and T297I （9.5%）. Conclusion In China, LTNP had stable conserved neutralization epitope and rarely happened amino acids mutation except 2G12 epitope compared with HIV/AIDS patients. Among mutant neutralization epitope on HIV gp120 C2-C3 region, the constituent ratio of 2G12 epitope was much higher than that of CD4BS and CD4i epitope. The mutation degrees of amino acids on conserved neutralization epitope were different.