银杏内酯A对实验性自身免疫性脑脊髓炎小鼠T细胞的免疫调节作用

Immunomodulatory effect of Ginkgolide A on T cells on experimental autoimmune encephalomyelitis mice

目的:明确银杏内酯A(GA)对实验性自身免疫性脑脊髓炎(EAE)小鼠的疗效,探讨GA对T细胞的免疫调节作用。方法:将C57BL/6雌性小鼠分为用GA治疗EAE小鼠的EAE治疗组(ET)、用生理盐水治疗EAE小鼠的EAE对照组(EC)及用生理盐水处理正常小鼠的正常对照组(HC)。用髓鞘少突胶质细胞糖蛋白35-55(MOG35-55)免疫EC组和ET组小鼠,制备EAE模型。免疫当天至第28天,记录各组小鼠的体重和临床评分。免疫后第28天取小鼠脊髓,制成冰冻切片进行HE和LFB染色;Western blot检测脊髓中炎症因子IL-17和IFN-γ表达;流式细胞术检测脾脏T细胞亚群变化。结果:对比EC组,GA能够缓解EAE小鼠症状的严重程度(P<0.01),减少体重丢失(P<0.05),抑制中枢神经系统炎症细胞浸润(P<0.05),减轻髓鞘脱失(P<0.001),抑制表达IL-17和IFN-γ的CD4+T细胞亚群比例(P<0.05),上调CD4+TGF-β+和CD4+IL-10+T细胞亚群百分比(P<0.000 1);此外,GA可下调脊髓中IL-17(P<0.01)和IFN-γ(P<0.05)表达。结论:GA通过调节T细胞亚群平衡,尤其是抑制Th1和Th17介导的炎症反应,减轻EAE小鼠临床症状。

Objective:To clarify the efficacy of Ginkgolide A(GA)on experimental autoimmune encephalomyelitis(EAE mice,and explore the immune regulating effect of GA on T cells.Methods:Female C57 BL/6 mice were divided into EAE treatment group(ET)treated with GA,EAE control group(EC)and Healthy control group(HC)treated with normal saline.EC group and ET group were immunized with myelin oligodendrocytes glycoprotein 35-55(MOG35-55)to prepare EAE model. Body weight and clinical scores of mice in each group were recorded from the immunization day to the 28 th day. On the 28 th day after immunization,the mouse spinal cord was taken and made into frozen sections for HE and LFB staining.Spinal protein was extracted and Western blot was used to detect expression of IL-17 and IFN-γ of T cells markers. Changes of T cells subsets in spleen were detected by flow cytometry.Results:Compared with EC group,GA could alleviate the severity of symptoms(P<0.01),reduce the degree of weight loss in EAE mice(P<0.05),inhibite the infiltration of inflammatory cells in the central nervous system(P<0.05),alleviated myelin loss(P<0.001),inhibite proportion of CD4+T cell subsets expressing IL-17(P<0.01)and IFN-γ(P<0.05),but increase percentages of CD4+TGF-β+and CD4+IL-10+T cell subsets(P<0.000 1). In addition,GA could inhibite expression of IL-17(P<0.01)and IFN-γ(P<0.05)in spinal cord.Conclusion:GA can alleviate the clinical symptoms of EAE mice by regulating balance of T cell subsets,especially by inhibiting Th1 and Th17 mediated inflammatory responses.