HIV-1感染者CD4＾＋T细胞受体基因多样性特点及其与病毒载量的相关性

Association of T cell receptor diversity of CD4 ^＋ T lymphocytes with viral load in individuals with HIV-1infection

目的分析HIV-1感染者CD4^＋T细胞受体（TCR）基因的多样性特征及其与病毒载量的相关性。方法应用抗CD4单克隆抗体从25份HIV-1感染者和10份HIV-1阴性对照样本外周血单个核细胞（PBMC）中分离CD4^＋T细胞，提取细胞总RNA，然后通过逆转录及巢式多聚酶链反应（nested-PCR）对TCR22个vβ基因家族的互补决定区3（CDR3）进行扩增，利用AB13700测序仪对扩增的PCR产物进行扫描，定量分析HIV-1感染者TCRCDR3区多样性变化特征及其与病毒载量的相关性。结果HIV-1感染者CIM^＋T细胞TCRCDR3区平均D（distance）值显著高于正常对照组（P〈0．05），TCR Vβ基因各家族CDR3长度谱型成寡克隆分布，TCRCDR3区的紊乱与病毒载量呈正相关（r=0．494，P〈0．05）；HIV-l感染引起TCR多样性的改变不仅表现在不同vβ基因家族上，而且也表现在CDR3长度上，其中感染者VB8、V1322、Vβ23基因家族的变化与正常人差异有统计学意义。结论HIV-1感染能引起CD4^＋T细胞TCR基因多样性的减少及高斯（Gaussian）分布的破坏，TCRCDR3区的紊乱与病毒载量呈正相关。

Objective To assess the impact of the virus on the complementary determining region 3 （CDR3） length diversity of T cell receptor（TCR） Vβ repertoires of CD4 ^＋T lymphocytes and to explore its association with viral load in individuals with HIV-1 infection. Methods The TCR repertoire was examined using spectratyping of CDR3 length diversity within CD4^＋ T cells in HIV infected and healthy adults. Separation of CD4^＋ T cells from peripheral blood mononuclear cells （PBMCs） was carried out by using immunomagnctic beads coated with anti-CD4 antibody. Total RNAs from the purified CD4 ^＋ T lympbocytes were isolated and used to perform nested-PCR amplifications in CDR3 of 22 TCR gene families. CDR3 diversity and its association with viral load in individuals with HIV-1 infection were analyzed. Results An average diversity for all CDR3 profiles in CD4 ^＋ T cells from 25 HIV-infected individuals was significantly different as compared to 10 age-matched healthy donors （P 〈 0.05 ） with the HIV-infected individuals losing diversity in the CDR3 profiles. There was positive correlation between changes in TCR CDR3 diversity and viral load （ r = 0.494, P 〈 0.05 ）. The changes in CDR3 length diversity of Vβfamilies in HIV-infected individuals, particular in Vβ8, Vβ22, Vβ23 were statistically different from the healthy controls. Conclusion HIV-1 infection might induce the loss of TCR Vβ repertoire diversity and disrupt the CDR3 Gaussian distributions within CD4 ＋ T cells. There should be positive correlation between changes in TCR CDR3 diversity and the viral load in HIV-1 infected patients.