XGD-1对人外周血T淋巴细胞增殖和IL-2R表达的影响

The Effects XGD-1 on the Proliferation of Human Peripheral Blood T Lymphocyte and the Expression of IL-2R

目的 探讨XGD 1的免疫抑制作用及其作用机理。方法 不同浓度的XGD 1作用于植物血凝素 (PHA)和刀豆素A(ConA)诱导的正常人外周血T淋巴细胞 ,共同培养 48h和 72h ,用改良MTT法观察XGD 1对人T淋巴细胞增殖的影响 ,用流式细胞术检测XGD 1对T淋巴细胞表面IL 2R表达的影响 ;同时观察联合应用CsA和XGD 1对细胞增殖及IL 2R表达的影响。结果 XGD 1对PHA和ConA诱导的正常人外周血T淋巴细胞增殖有明显的抑制作用 ,其作用与药物浓度有关 ,在一定剂量范围内 ,抑制作用随XGD 1剂量的递增而加强 ;XGD 1对PHA和ConA激活的T淋巴细胞表面IL 2R的表达有显著抑制作用 ,阳性率从正常对照活化细胞的 47.67%降为 2 5 .0 3 % ;联合应用CsA ,上述抑制作用增强。结论 XGD 1具有免疫抑制作用 ,能降低IL 2R表达 ,可能是其免疫抑制作用的重要机理之一。

Objective To explore the immunosuppressive effect of XGD 1 and its mechanism. Methods Different concentrations of XGD 1 were added to PHA or ConA induced human peripheral blood T lymphocyte.Seventy two hours later modified MTT assay was employed to test the effect of XGD 1 on T cell proliferation. Flowcytometry was used to examine the effect of XGD 1 on the expression of IL 2 receptor(IL 2R) on the surface of T cells individually at 48 h and 72 h.And the effects of XGD 1 combined with cyclosporine A(CsA) on the proliferation of T lymphocytes and the expression of IL 2R were also investigated. Results In the concentration range of 0.2～25 μg/ml,XGD 1 exerted marked inhibitory effect on PHA or ConA induced T cell proliferation,which was proportional to dose. Flowcytometry showed that XGD 1 inhibited the expression of IL 2R,and the percentage of IL 2Rα positive cells after stimulation of PHA decreased from 47.67% to 25.03% in the presence of XGD 1 (1 μg/ml).XGD 1 and CsA had synergism in inhibition of T cell proliferation and IL 2R expression. Conclusion The study suggests that XGD 1 has immunosuppressive effect. The suppressive effect of XGD 1 on T cell proliferation is most probably mediated by decreasing IL 2R expression.