银屑病患者皮损和外周血中CD8α＋α＋T细胞的研究

CD8α＋α＋ T cells in lesions and peripheral blood of patients with psoriasis

目的 观察银屑病患者皮损和外周血中CD8α＋α＋T细胞的分布和比例,探讨其在银屑病发病中的作用.方法 采用免疫荧光技术观察5例进展期寻常性银屑病患者和5例健康人皮肤中CD8α＋α＋T细胞的分布,流式细胞仪分别检测10例进展期寻常性银屑病患者和8例健康人外周血中CD8α＋α＋T细胞比例及干扰素γ（IFN-γ）和肿瘤坏死因子α（TNF-α）的表达.采用Graphpad Prism统计软件对实验组和对照组各数据进行t检验.结果 在5例银屑病患者皮损真皮浅层均可见以CD8α＋α＋T细胞为主的浸润,未见明显的CD8α＋β＋T细胞浸润;而5例健康人皮肤中均未见CD8α＋α＋T细胞和CD8α＋β＋T细胞浸润.流式细胞仪检测,8例健康人外周血中CD8α＋α＋T细胞比例为9.12％±4.80％,10例银屑病患者组为26.47％±12.99％,银屑病患者组明显高于对照组,两组比较,t=3.96,P＜ 0.001.在银屑病患者外周血CD8α＋α＋T细胞中分泌IFN-γ和TNF-α的细胞比例分别为47.36％±19.38％和54.14％±21.14％,健康对照组分别为13.44％±9.21％和34.03％±17.22％,两组差异均有统计学意义（t值分别为4.54和2.17,P值分别＜0.001和＜0.05）.结论 银屑病患者皮损和外周血中存在CD8α＋α＋T细胞的分布和比例增多,CD8α＋α＋T细胞可能是参与银屑病发病的主要CD8＋T细胞亚群.

Objective To investigate the distribution and proportion of CD8α＋α ＋ T cells in lesions and peripheral blood of patients with psoriasis,and to assess their roles in the pathogenesis of psoriasis.Methods An immunofluorescence assay was performed to observe the distribution of CD8α＋α＋ T cells in lesions of 5 patients with progressive psoriasis vulgaris and normal skin of 5 healthy human controls.Flow cytometry was conducted to determine the proportion of CD8α＋α＋ T cells,and to measure the expressions of interferon （IFN）-γ and tumor necrosis factor （TNF）-α in peripheral blood from 10 patients with progressive psoriasis vulgaris and 8 healthy human controls.Statistical analysis was carried out by t test with GraphPad Prism software.Results A massive infiltrate mainly composed of CD8α＋α＋ T cells but not CD8α＋β＋ T cells was observed in the upper dermis of lesions from the 5 patients with psoriasis,while there was no infiltrate of CD8α＋β＋ or CD8α＋α＋ T cells in the normal skin of 5 healthy human controls.Flow cytometry revealed that the proportion of CD8α＋α＋ T cells was significantly higher in peripheral blood from 10 patients with psoriasis than in that from 8 healthy human controls （26.47% ± 12.99% vs.9.12% ± 4.80%,t =3.96,P〈 0.001）.Significant differences were also noted between the psoriatic patients and healthy human controls in the percentage of cells secreting IFN-γ （47.36% ± 19.38% vs.13.44% ± 9.21%,t =4.54,P 〈 0.001） and cells secreting TNF-α （54.14% ± 21.14% vs.34.03% ± 17.22%,t =2.17,P 〈 0.05） in peripheral blood CD8α＋α＋ T cells.Conclusions Both the distribution and proportion of CD8α＋α＋ T cells are increased in lesions and peripheral blood from patients with psoriasis,suggesting that CD8α＋α＋ T cells may be the main subgroup of CD8＋ T cells that contribute to the pathogenesis of psoriasis.