B7-H1在HIV／艾滋病患者外周血髓样树突状细胞上的表达及临床意义

Expression of B7-H1 on peripheral myeloid dendritic cells in patients with HIV infection and its correlation with diseases progression

目的观察病情不同的HIV／AIDS患者外周血髓样树突状细胞（mDC）上B7-H1表达频率和疾病进展的关系。方法采集2006年3月至2008年4月北京佑安医院门诊或住院的82例未经抗逆转录病毒治疗（ART）的HIV／AIDS患者、28例ART病毒学完全应答者（CR）和14名健康人的外周血，采用流式细胞术分析mDC上B7-H1表达频率。所有病例均用流式细胞仪检测外周血CIM细胞计数，用bDNA法检测血浆HIV-1病毒载量。结果AIDS患者外周血mDC上B7-H1表达频率为14．15％±2．63％，HIV无症状感染者为3．31％±0．51％，健康对照为0．52％±0．10％，显示AIDS患者〉HIV感染者〉健康对照（均P〈0．05）。长期不进展者（LTNP）和典型进展者（TP）mDC上B7-H1的表达频率分别是3．12％±1．14％和8．12％±1．37％，均显著高于健康对照组（均P〈0．05），且TP患者高于LTNP（P=0．001）；HIV／AIDS患者mDC上B7-H1表达频率与CD4细胞计数呈显著负相关，而与血浆病毒载量显著正相关（r值分别为-0．631及0．482，均P〈0．01）。28例CR患者mDC上B7-H1表达频率为6．59％±1．43％，显著低于AIDS患者（P〈0．01）。CR患者中，C1M细胞计数〈250个／μl的患者mDC上B7-H1表达频率高于CD4细胞计数〉250个／μl的患者（P〈0．001）。ART纵向观察结果显示，6例患者在14～52周的抗病毒治疗后，血浆病毒载量均显著降低，有不同程度的CIM细胞计数升高，而mDC上B7-H1表达有不同程度降低，CIM细胞计数显著升高的病人mDC上B7-H1表达显著降低。结论共刺激分子B7-H1在HIV／AIDS患者外周血mDC上高表达，并与疾病进展密切相关，是疾病进展的指标。

Objective To investigate the features of B7-H1 expression on peripheral myeloid dendritic cells （mDCs） in patients with HIV infection and evaluate the correlations between B7-H1 expression and disease progression. Methods Peripheral blood samples from 82 treatment-naive patients with HIV infection, 28 viral complete responders （CRs） under antiretroviral therapy （ART） and 14 healthy controls （HCs） were collected. Flow cytometry was applied to investigate the expression of B7-H1 on mDCs and CD4 cell counts. Plasma HIV-1 viral load was detected by bDNA. Results The frequency of B7-H1 expression on mDCs were 14. 15% ± 2.63% , 3.31% ±0. 51% and 0. 52% ±0. 10% in AIDS patients, asymptomatic HIV infected individuals and HCs respectively. As compared with HCs, B7-H1 was significantly up-regulated on mDCs in HIV/AIDS patients. The order was as follows： AIDS patients 〉 asymptomatie HIV infected individuals 〉 HCs （ all P 〈 0. 05 ）. Interestingly, the expression of B7-H1 on mDCs in long-term nonprogressors （LTNPs） was 3.12% ±1.14%. And it was lower than that in typical progressors （TPs） [8. 12% ±1.37% （P =0. 001 ） ]. Moreover, the expression of B7-H1 was negatively correlated with C1M cell counts and positively correlated with plasma viral load in these patients （r = -0.631, P 〈 0.01 and r = 0.482, P 〈 0.01 respectively）. The expression of B7-H1 on mDCs was significantly lower in ART complete responders than that in AIDS patients （6. 59% ±1.43% vs 14. 15% ±2. 63% ） （P 〈0. 01 ）. Expression of B7-H1 on mDCs decreased markedly in patients whose CD4 cell counts greatly elevated after a successful antiretroviral treatment. Conclusion The expression of BT-H1 on mDCs is significantly up-regulated in HIV/AIDS patients. With a close correlation with disease status, it acts as a marker of disease progression.