PD-1分子对慢性丙型肝炎患者T细胞免疫功能的影响

目的 探讨慢性丙型肝炎患者外周血T细胞表面程序性死亡因子-1（PD-1）分子在T细胞免疫应答中的作用。方法受试对象包括40例慢性丙型肝炎患者,10例非病毒性肝炎的肝病患者,以及20名健康对照。取外周血,采用流式细胞术检测CD4^＋及CD8^＋T细胞上PD-1的表达水平;ELIsA法测定混合淋巴细胞培养上清中IFN—γ及IL-2的浓度。结果慢性丙型肝炎患者外周血CD4^＋及CD8^＋T细胞上PD-1阳性表达率[（38．61±4．35）％、（48．17±5．16）％]明显高于其他肝病患者及健康对照（P〈0．01）。慢性丙型肝炎患者产生Ⅰ型细胞因子的能力明显降低,阻断PD-1共刺激信号途径能够增强患者T细胞分泌I型细胞因子的能力。结论慢性丙型肝炎患者外周血T细胞上PD-1表达水平的升高,可能是导致T淋巴细胞应答能力下降的重要原因。

Influence of PD-1 on T cell immunity in the course of chronic HCV infection

Objective To explore the influence of PD-1 on peripheral T cells from chronic HCV patients during the process of T-cell-associated immune response. Methods Forty patients with chronic hepatitis C, 10 patients with non- HCV liver disease, and 20 healthy controls were enrolled in our study. The expression of PD-1 on CD4^＋ and CD8^＋ T cells were detected by flow eytometry. ELISA was used for cytokine production of IFN-7 and IL-2 during allogeneie mixed leukocyte reactions （MLR）. Results The percentage of PD-1 ＋ distinct subpopulations of CD4^＋ T cells （38.61 ± 4.35） and CD8^＋ T cells （48.17± 5. 16） were significantly increased in peripheral blood cells from patients with HCV compared with healthy individuals and patients with non-HCV liver disease （P〈 0. 01 ）. Furthermore, type 1-cytokine production of T cells was decreased. The blockage of PD-1 co-stimulatory signals could reverse the cytokine production. Conclusion Up-regulation of PD-1 on peripheral T cells from HCV patients may explain the reduction of T cell responsibility during the process of immunopathogenesis.