银屑病患者角质形成细胞对T淋巴细胞CD25、CD69表达的影响

Effects of psoriatic keratinocytes on the expression of CD25 and CD69 in T lymphoeytes

目的探讨银屑病患者角质形成细胞（KC）对T淋巴细胞CD25、CD69表达的影响。方法分离10例银屑病患者KC，密度梯度离心法分离单一核细胞（PBMC）；流式细胞仪检测混合培养后T细胞活化标志CD25、CD69的表达。结果银屑病患者皮损KC作用的自体外周血T细胞CD25、CD69表达水平分别与非皮损KC作用组及自体T细胞自然增殖组相比显著增高，银屑病非皮损KC＋自体T细胞共培养组与自体T细胞自然增殖组相比，差异无统计学意义。银屑病皮损、非皮损KC作用的正常人T细胞CD25、CD69表达均显著高于正常人外周血T细胞自然增殖组，银屑病皮损KC＋正常人T细胞共培养组与非皮损组相比，差异无统计学意义。结论银屑病患者局部存在慢性炎症反应，可能是由于皮损KC免疫表型发生改变从而作为自身抗原，启动自身免疫反应。

Objective To investigate the effects of psoriatic keratinocytes on the expression of CD25 and CD69 in T lymphocytes. Methods Keratinocytes were isolated from the biopsy samples resected from the lesions and adjacent non-lesional area of 10 patients with psoriasis, and cultured in 5% CO2 at 37 ℃ in 24-well plates. Density gradient centrifugalization and glass adherence method were applied to detach peripheral blood mononuclear cells （PBMC） and peripheral blood T lymphocytes （PBTL） from anticoagulant blood samples of the same 10 psoriatic patients and 10 normal controls. PBMCs of 1 × 10^5/well were added to the wells containing cultured keratinocytes of 1 × 10^5/well, then gamma rays were used to inactivate these cells. Following that, PBTLs of 1 × 10^6/well were inoculated into the 24-well plate containing inactivated keratinocytes and PBMCs, and cultured in 5% CO2 at 37 ℃. Those PBTLs cultured without the presence of keratinocytes or PBMCs served as the natural growth control. Three days later, flow cytometry was performed to detect the expression of CD25 and CD69 in PBTLs. Results There was a significant increase in the expression of CD25 and CD69 in psoriatic PBTLs cocultured with lesional keratinocytes compared with those cocultured with non-lesional keratinocytes and natural psoriatic controls. Also, the expression of CD25 and CD69 was increased in normal PBTLs cocultured with lesional or non-lesional keratinocytes of psoriatc patients than those in the natural normal controls. No significant difference was observed in the expression of CD25 or CD69 between psoriatic PBTLs cocultured with non-lesional keratinocytes and natural psoriatic PBTLs, or between the normal PBTLs cocultured with lesional keratinocytes and those with non-lesional keratinocytes （P 〉 0.05）. Conclusions Psoriatic keratinocytes may act as an autoantigen to trigger autoimmune response and eventually lead to a chronic local inflammation in patients with psoriasis.