人类免疫缺陷病毒/艾滋病患者中和抗体保守表位氨基酸变异研究

Study on amino acid mutations in conserved neutralization epitopes in HIV-infected individuals and AIDS patients in China

目的探讨人类免疫缺陷病毒/艾滋病(HIV/AIDS)患者中和抗体保守表位氨基酸变异特征,为开展中和抗体免疫治疗和疫苗设计奠定理论基础。方法RTPCR及nestPCR扩增HIV/AIDS患者HIV1外膜envC2～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,并与HIV1SequenceDatabase参考毒株中和抗体表位数据比对辨别其保守表位氨基酸突变情况。结果HIV1外膜蛋白gp120C2～C3区,HIV感染者和AIDS患者CD4结合位点(CD4BS)、CD4诱导(CD4i)、2G12三种类型中和抗体保守表位氨基酸均存在突变,两组病例表位突变率差异无统计学意义(均P>0.05);CD4BS保守表位突变有370E/Q(12.1%),370E/K(4.5%),266A/S(1.5%),368D/E(1.5%);CD4i保守表位突变有370E/Q(12.1%),370E/K(4.5%),381E/D(7.6%),381E/V(1.5%);2G12保守表位突变有295N/V(19.7%),295N/T(6.1%),295N/D、295N/K、295N/E(各1.5%),297T/I(9.1%),297T/S、297T/N(各1.5%)。结论我国HIV/AIDS患者HIV1外膜蛋白gp120C2～C3区中和抗体CD4BS、CD4i、2G12保守表位氨基酸均存在突变,但尚处于低突变水平;不同类型中和抗体保守表位各氨基酸位点的变异程度有差异。

Objective To study the amino acid mutations in conserved neutralization epitopes in HIV-infected individuals and AIDS patients in China. Hopefully this will provide a basis for the neutralizin gantibodies immunotherapy and the design of vaccines. Methods RT-PCR and nest-PCR methods were used to amplify genes in the HIV-1 env C2-C3 region. Nucleic acids sequence were detected by double-deoxygen terminal method and translated into amino acids for analysis. The mutations of conserved neutralization epitopes were identified by comparison with the epitopes reference data in HIV-1 Sequence Database. Results Both HIV-infected individuals and AIDS patients demonstrated that there were three types conserved neutralization epitope mutations on HIV-1 gpl20 C2-C3 region, including： CI4-binding site （CIMBS）,CI4-induced （CI4i） and 2G12. The mutation rates showed no significant difference （P 〉0. 05）. CI4BS conserved neutralization epitope mutations focused on 370E/Q （12. 1%）, 370E/K （4.5%）, 266A/S（1.5%） and 368D/E （1.5%）. CD4i conserved neutralization epitope mutations focused on 370E/Q （ 12. 1% ）, 370E/K （4. 5% ） , 381E/D （7.6%） and 381E/V （ 1.5% ）. 2G12 conserved neutralizationepitope mutations focused on 295N/V（ 19. 7% ）, 295N/T （6. 1% ） , 295N/D（ 1.5% ） , 295N/K（ 1.5% ） ,295N/E（1.5%）, 297 T/I（9.1%）, 297T/S（1.5%） and 297T/N（1.5%）.Conclusion In both HIVinfected individuals and AIDS patients in China demonstrated a low level mutations in three types conserved neutralization epitope identified on HIV-1 gpl20 C2-C3 region, including： CD4BS, CD4i and 2G12. The mutation degrees of amino acids in conserved neutralization epitopes were different.