TGF-β与IL-6介导的骨髓基质干细胞对EAE的双向调节作用研究

Study on the Reciprocal Effect of Mesenchymal Stem Cell on EAE Mediated by TGF-β and IL-6

目的:探讨在实验性自身免疫性脑脊髓炎(EAE)治疗中TGF-β与IL-6介导的骨髓基质干细胞(BMSCs)的双向调节作用与机制。方法:分离纯化BMSCs,并与EAE大鼠动物模型淋巴细胞共培养,应用抗TGF-β和IL-6单克隆抗体封闭TGF-β或IL-6通路,ELISA检测不同比例MSC与淋巴细胞共培养中对细胞因子的作用,流式细胞仪检测MSC对Th细胞亚群分化的影响,过继免疫临床评分检测BMSC治疗中的关键通路。结果:1:10比例BMSCs共培养组与对照组相比,IL-17分泌量下降(P<0.05),Treg细胞显著增高(P<0.05)而Th17细胞显著降低(P<0.05),共培养后的淋巴细胞进行过继免疫回输后,1:10干细胞共培养组临床评分显著降低(P<0.05),而1:100比例共培养组与上述结果相反,中和TGF-β和IL-6抗体可以调节此免疫作用。结论:BMSCs通过TGF-β和IL-6通路调节免疫系统调节性T细胞(Treg)和Th17的细胞平衡,此过程与BMSCs剂量密切相关,本研究可为干细胞更好的临床应用提供理论基础。

Objective： To investigate the mechanism and reciprocal effect of mesenchymal stem cell on EAE via TGF-β and IL-6 pathway.Methods： BMSCs were purified and co-cultured with lymphocytes harvested from the lymph nodes of rats with EAE after the immunization at different concentrations.Neutralizing anti-TGF-β or anti-rat IL-6 monoclonal antibodies were added to the culture system.Cell culture supernatant cytokine concentrations were determined by ELISA test and Flow cytometry test was used to examine the Th cells differentiation.The effect of msc was determined by clinical scores of adoptive transfered EAE.Results： More Treg cells and fewer Th17 cells were observed at the 1：10 BMSC： lymphocyte co-culture ratio.At this ratio,TGF-β neutralizing antibodies reversed the stimulatory effects of MSCs on the proportion of Tregs.However,more Th17 cells were observed in the 1：100 MSC： lymphocyte co-culture group and TGF-β and IL-6 neutralizing antibodies reversed this effect.Conclusions： In this report we demonstrate that BMSCs have the capacity for modulating antigen-stimulated T cells to differentiate into either Th17 or Treg cells in a dose-dependent manner,respectively via pathways involving TGF-β and IL-6.These results may lead better utility of BMSCs as a treatment for autoimmune disease.