HIV感染后外周血肠道归巢CD8细胞及其亚群变化特点研究

Study of peripheral gut-homing CD8 T cell and its subpopulation in HIV infection

目的探讨艾滋病病毒(HIV)感染后,外周血肠道归巢CD8+T淋巴细胞(简称CD8细胞)及其功能亚群的变化特点。方法选取85例符合诊断标准的无症状HIV感染者:治疗前43例,治疗后42例,同时选取45例健康对照。采用流式细胞表面染色及全血胞内细胞因子染色方法,使用BD FACSCanto流式细胞仪检测各项指标,FACSDiva软件分析肠道归巢α4+β7+RO+CD8+T细胞及其功能亚群Tc1和Tc17的变化,比较各组之间的差异。结果未治疗组HIV感染者外周血肠道归巢α4+β7+RO+CD8+T细胞表达百分比及绝对值均显著上升,高于健康对照[(14.74±7.74)%vs(5.53±2.66)%,P<0.001;(96.19±68.92)个/μL vs(24.59±9.48)个/μL,P<0.001]。经抗病毒治疗后,肠道归巢α4+β7+RO+CD8+T细胞的百分比可部分下降,与健康对照组相比差异无统计学意义[(6.91±5.37)%vs(5.53±2.66)%,P=0.100],但绝对值仍显著高于健康对照[(49.35±44.23)个/μL vs(24.59±9.48)个/μL,P<0.001];HIV感染后α4+β7+RO+Tc1细胞的百分比及绝对值均显著增高[(86.48±12.59)%vs(73.66±14.60)%,P<0.001;(91.50±65.97)个/μL vs(20.97±9.73)个/μL,P<0.001],抗病毒后α4+β7+RO+Tcl的百分比和绝对值均显著下降,但仍明显高于健康人[(82.59±13.03)%vs(73.66±14.60)%,P<0.001;(40.51±65.97)个/μL vs(37.00±9.73)个/μL,P<0.001];而α4+β7+RO+Tc17细胞百分比在HIV感染后显著降低,与健康对照比差异有统计学意义[(1.08±1.59)%vs(4.51±3.41)%,P<0.001];抗病毒治疗后可恢复至正常水平,与健康对照相比无显著差异[(2.99±2.28)%vs(4.51±3.41)%,P=0.091),但α4+β7+RO+Tc17绝对值在治疗前后无明显变化(P>0.05)。结论外周血α4+β7+RO+CD8+T细胞作为可以间接反应肠道CD8细胞变化的可靠指标,在HIV感染后显著增高,而其功能亚群则出现平衡紊乱,在HIV致病机制中可能起重要作用,对其变化特点的追踪可以为疗效监测及疫苗研究提供重要的循环标志。

Objective To evaluate the characteristics of peripheral gut-homing CD8 T cell and its subpopulation after HIV infection. Methods 85 asymptomadc HIV infected patients and 45 healthy volunteers participated in the study. The patients were divided into two groups, one before and another after treatment. The whole blood surface and intracellular cytokine staining were used, and samples detected by BD FACSCanto. After then, the expression of gut-homing α4^＋β7^＋RO^＋CD8^＋ T cell and its subpopulation Tcl and Tcl7 were analyzed by FACSDiva software and the differences between groups were compared. Results The percentage and absolute number of α4^＋β7^＋RO^＋Tc1T cell in naive-therapy patients significantly increased, more than those in the healthy control [（14.74± 7.74）% vs （5.53± 2.66）%,P〈0. 001; （96.19± 68.92） cell/μL vs （24.59± 9.48） cell/μL,P〈0. 001]. ART treatment could bring the percentage of gut-homing CD8 T cell to nearly normal level[（6.91±5.37）% vs （5.53±2.66）%,P=0.100], but not the absolute number [（49.35 ±44.23） cell/μL vs （24.59 ± 9.48） cell/μL,P〈0. 001]. The IFN-γ/-producing gut-homing Tcl showed significant increase in terms of either frequency or absolute number [（86.48 ± 12.59） % vs （73.66± 14.60）,P〈0.001]（91.50±65.97） cell/μL vs （20. 9729.7） cell/μL,P〈0. 001], while the percentage of IL-17-producing gut-homing Tcl7 decreased [（1.08 ± 1.59） % vs （4.51 ± 3.41） %, P〈0. 001] and the absolute number remained stable after HIV-1 infection （P〈0.05）. ART restored partially the frequencies of gut- homing TclT[-（1.08±1.59）% vs （4.51±3.41）% ,P〈0. 001], but the increased number of gut-homing Tcl subset was found irreversibleP（82.59±13.03）% vs （73.66±14.60）%,P〈0. 001; （40. 51±65.97） cell/μL vs （37.00± 9.73） cell/μL,P〈0. 001]. Conclusion As a credible marker for indirect tracking of gut-homing CD8 T cell, peripheral α4^＋β7^＋RO^＋CD8^＋ T cell increases significantly after HIV infection with its functional subpopulation disturbed severely. This suggests that gut-homing CD8^＋ T cell may play an important role in the pathogenesis of HIV. Tracking their changes may provide useful bio-markers for treatment and vaccine efficacy studies.