骨髓间充质干细胞对实验性自身免疫性重症肌无力临床及免疫功能影响的研究

Effects of Bone Marrow Mesenchymal Stem Cells on the Clinical Manifestation and the Immune Function of Experimental Autoimmune Myasthenia Gravis

目的:探讨骨髓间充质干细胞(MSCs)对实验性自身免疫性重症肌无力(EAMG)临床及免疫功能的影响。方法:EAMG大鼠模型20只分为移植组(n=10)和模型对照组(n=10),并设正常对照组(n=10)。收集从Lewis鼠骨髓中分离、培养及鉴定后的MSCs,并调至密度为1×106/100μLPBS。移植组经尾静脉注入MSCs悬液100μL,模型对照组及正常对照组同期给予100μLPBS。定期对移植组和模型对照组行体重测定、Lennon临床评分以及血浆中AChRa97-116-Ab含量测定,并采用RT-PCR和ELISA法分别检测3组大鼠外周血单核细胞(PBMCs)中T-bet、GATA-3以及血浆中IFN-γ和IL-4含量。结果:移植组Lennon临床评分、AChRa97-116-Ab含量以及T-bet、GATA-3、IL-4、IFN-γ水平均较模型对照组显著降低,与正常对照组比差异无统计学意义;模型对照组T-bet与IFN-γ以及GATA-3与IL-4均呈显著正相关。结论:MSCs移植可以有效减轻EAMG症状,其可能作用机制是抑制T-bet和GATA-3表达,从而下调AChR特异性T和B细胞异常的免疫应答。

Aim： To explore the effects of marrow mesenchymal stem cells（MSCs） on the clinical manifestation and the immune function of EAMG. Methods： 20 EAMG rats were determined and divided randomly into the transplantation group and the model control group, each group had 10 rats, and prepared 10 healthy rats as the normal control group. MSCs were obtained from Lewis rats and planted in plastic culture capsule, then cultured and expanded in vitro. MSCs were identified by flow cytometry. Transplantation group were injected with 1× 10^6 MSCs diluted in PBS （100μL） and with an equal volume of PBS in the model control and the normal control group. And then the body weight and clinical symptoms of rats in transplantation and model control group were evaluated at the same time every day. The titers of AChRa97-116-Ab in plasma were detected by ELISA after 2 weeks of transplantation. The expression of T-bet/GATA-3 in PBMCs were measured by RT-PCR in the three groups, IFN-7, IL-4 in plasma were detected by ELISA in the three groups after 3 weeks of transplantation. Results： The clinical score, the titers of AChRa97-116-Ab, and the expression of T-bet/GATA-3, IFN-γ, IL-4 in the transplantation group were obviously lower than those in the model control group. There were no significant difference between the transplantation and the normal control group. IFN-γ and IL-4 were positively correlated with T-bet and GATA-3 in the model control group, respectively. Conclusion： Bone marrow mesenchymal stem cells could ameliorate muscular weakness in EAMG rats via suppressing T-bet/GATA-3 expression and downregulating of AChR-specific B-cell responses and AChR- reactive T-cell function.