基于深圳男男同性性行为人群的HIV-1广谱中和抗体筛选分析

Screening and Analysis of the HIV-1 Broadly Neutralizing Antibodies based on Shenzhen MSM Crowd

目的:筛选基于深圳本地男男同性性行为者(Men who have sex with men,MSM)人群队列中HIV-1流行毒株的广谱中和抗体(Broadly neutralizing antibodies,bn Abs),为下一步机制和应用研究奠定基础。方法:建立小型MSM队列,按计划分别定期随访、留样,测序分析人群中HIV-1病毒流行亚型。选取将骨架质粒与系列标准HIV-1 env质粒12款,分别共转染293细胞制备单次感染能力假病毒。建立TZM-bl细胞实验测定并计算中和活性(ID50Titers)技术平台,用于选定病毒亚型样品的筛选。最后取所获具有一定广谱中和抗性的代表性血样,通过抗体竞争实验初步分析其结合位点。结果:近年来,深圳MSM的HIV-1流行亚型分布中,CRF07_BC(43.4%)和CRF55_01B(15.4%)占比快速增长。选择来自该人群队列CRF07_BC感染者34人88份血样进行广谱中和抗性检测,筛选出具有一定广谱中和抗性的血样10份(ID50 Titer≧25),其中2例显示了较佳中和宽度,可作用于全部12种假病毒中的7种(58.3%)。初步分析其结合机制均非靶向gp120。结论:本研究成功建立小型MSM队列和TZM-bl检测分析技术并应用于实践,初步筛选结果提示部分具有中和活性的患者血清内存在bn Abs。

Objective： To screen broadly neutralizing antibodies（bnAbs） of HIV-1 epidemic strains in Men who have sex with men （MSM） lived in Shenzhen, and provide basis for the mechanism and application research. Methods： A small crowd of local MSM was established. Participants were followed up and saved samples regularly, HIV-1 subtype distribution from these sampled local MSM was also analyzed by sequencing. In this study, 12 kinds of Standard HIV-1 Env-pseudotyped viruses were prepared, which were produced by cotransfecting 293T cells with env expression plasmid and HIV-1 backbone expression plasmid, for TZM-bl-based neutralization assay. Samples selected from local MSM crowd were detected and ID50 titers were calculated through sera neutralization curves. Individuals showed relatively more broad or potent neutralizing activity would be analyzed by additional neutralization competition assay. Results： HIV-1 subtype distribution from local MSM significantly changed in recently years, The prevalence of CRF07_BC （43.4 %）and CRF55 01B（15.4 %）increased rapidly. We detected 88 samples from 34 MSM with CRF07_BC infection, 10 samples from 6 individuals shown cross-clade neutralizing activity, 2 of them showed plasma neutralization breadth of 58.3 % against a multi-subtype panel, the pri- mary analysis indicated that the plasma neutralization in these two individuals is not directed to gpl20. Conclusions： A local MSM crowd and TZM-bl-based neutralization assay technology platform were successfully established in this study and applied to practice. Primary results indicated that HIV-1 bnAbs existed in part of samples.