HIV-1感染者CD4+CD25nt/hiCD127lo调节性T细胞PD-1表达水平与疾病进展的关系

目的:阐明HIV-1感染者外周血中具有CD4+CD25nt/hiCD127lo特征的调节性T细胞(Treg)表面PD-1的表达水平与疾病进展的关系.方法:选取108名未经治疗的不同进展期的HIV-1感染者和27名健康人对照, 采集静脉血, 用Ficoll-Hypaque密度梯度离心法分离获得PBMC, 加入PerCP-CD4抗体、 FITC-CD25抗体、 PE-CD127抗体和APC-PD-1抗体, 经细胞表面四色染色、流式细胞术(FCM)分析Treg表面PD-1的表达;另将50 L全血加入Trucount绝对计数管, 采用Multitest CD3/CD8/CD45/CD4试剂盒检测CD4+T细胞绝对数;分离静脉血血浆, NucliSens EasyQ测定血浆HIV-1病毒载量;实验数据采用SPSS14.0 统计学软件分析处理.结果:HIV-1感染者Treg表面PD-1表达水平显著高于健康人(5.33%±2.24% vs 1.72%±0.65%, P<0.01);AIDS期(7.87%±2.23%)明显高于进展期(5.21%±1.72%, P<0.05)和新近感染者(3.22%±1.01%, P<0.05);HIV-1感染者Treg表面PD-1表达水平与血浆中的HIV-1病毒载量和CD4+T细胞绝对数密切相关.结论:首次证实HIV-1感染者外周血中Treg表面PD-1表达增加, 且表达水平与病程进展相关.该结果为进一步揭示HIV-1感染中Treg的效应机制、探索新的免疫治疗方案提供了理论及实验依据.

Association of PD-1 expression on CD4+CD25nt/hiCD127lo regulatory T cells with disease progression in HIV-1 infected patients

AIM: To investigate whether Programmed death-1 (PD-1) expression on peripheral CD4~+CD25~(nt/hi)CD127~(lo) regulatory T cells (Treg) was associated with disease progression in HIV-1-infected patients. METHODS: Peripheral blood from 108 HIV-1-infected patients in distinct disease progression statuses and 27 healthy individuals were collected in the present investigation. PBMCs were isolated by centrifugation on Ficoll-Hypaque, followed by staining with anti-CD4-PerCP, anti-CD25-FITC, anti-CD127-PE and anti-PD-1-APC. PD-1 expression on Treg was analyzed by four-color staining flow cytometry. CD4~+T cell absolute counts were determined using Multitest CD3/CD4/CD8/CD45 kit and plasma viral loads were detected on NucliSens EasyQ. All data were analyzed using SPSS14.0 software. RESULTS: In peripheral blood of healthy individuals, Treg expressed PD-1 at very low levels (1.72%±0.65%). In contrast, Treg from HIV-1-infected patients showed a significantly increased PD-1 expression (5.33%±2.24%, P<0.01). Moreover, AIDS patients exhibited statistically higher PD-1 expression on Treg (7.87%±2.23%) than newly HIV-1 infected patients (3.22%±1.01%, P<0.05) and patients in progression to AIDS(5.21%±1.72%, P<0.05). PD-1 up-regulation on Treg was closely correlated with reduced CD4~+T cell absolute counts but elevated plasma viral load. CONCLUSION: Overall, we found that PD-1 expression on peripheral Treg was up-regulated and correlated with disease progression in HIV-1-infected patients for the first time. These findings not only extend our understanding of how Treg functions in HIV-1-infected patients but also support the notion that blocking PD-1/PD-L1 interactions may represent a potential therapeutic strategy for HIV-1-infected patients.