环孢素A对人扁桃体Tfh细胞产生IL-21以及对CD40L和Bcl-6表达的抑制作用

Suppressive effects of CsA on the production of IL-21 and the expression of CD40L and Bcl-6 in tonsillar Tfh cells

目的探讨环孢素A(CsA)对人扁桃体滤泡辅助性T(Tfh)细胞产生白细胞介素-21(IL-21)以及对CD40L和Bcl-6表达的影响。方法分离正常人外周血及扁桃体单个核细胞,利用PMA+Ionomycin刺激加入不同剂量的CsA,采用酶联免疫吸附试验(ELISA)和酶联免疫斑点试验(ELISPOT)检测IL-21和γ-干扰素(IFN-γ)的产生,利用流式细胞术检测扁桃体Tfh细胞中IL-21、IFN-γ、Bcl-6和CD40L的表达,同时检测Tfh细胞的表型特征。结果 CsA呈剂量依赖性抑制扁桃体Tfh细胞IL-21和IFN-γ的产生,并抑制Bcl-6和CD40L的表达。表型分析显示,CsA主要抑制记忆型Tfh细胞产生IL-21,即CD45RO+CCR7+/-。结论 CsA呈浓度依赖性地抑制人扁桃体Tfh细胞IL-21的产生并降低其Bcl-6和CD40L的表达,主要抑制记忆型Tfh细胞产生IL-21,为探讨环孢素A对Tfh细胞亚群免疫功能的影响提供了依据。

Objective To study the effects of cyclosporine A（CsA） on the production of IL-21 and the expression of CD40 L and Bcl-6 in tonsillar T follicular helper cells. Methods Isolated peripheral blood and tonsillar mononuclear cells were stimulated with PMA plus ionomycin in the presence or absence of different concentrations of CsA. The levels of IL-21 and IFN-γ were detected by ELISA and ELISPOT; the expression of IL-21 and IFN-γ were detected by flow cytometry and the phenotypic features of IL-21-expressing Tfh cells were analyzed by flow cytometry. Results CsA could inhibit the production of IL-21 and IFN-γ by Tfh cells in a dose-dependent manner. The expression of Bcl-6 and CD40 L can also be down-regulated by CsA in Tfh cells. Furthermore, CsA mainly inhibit the production of IL-21 by effector or central memory Tfh cells expressing CD45RO＋CCR7＋ /-. Conclusion CsA could inhibit the production of IL-21 in a dose-dependent manner. Simultaneously, CsA inhibited the expression of Bcl-6 and CD40 L in IL-21-expressing Tfh cells that were effector or central memory cells. These results provide basic theory for further understanding the effects of CsA on the immunologic function of Tfh cells.