霉酚酸酯对实验性自身免疫性脑脊髓炎大鼠血CD4~+ CD25+T细胞的影响

目的研究霉酚酸酯(MMF)对实验性自身免疫性脑脊髓炎(EAE)大鼠的治疗作用及血CD4+CD25+T细胞的影响。方法用豚鼠全脊髓匀浆和完全弗氏佐剂制成的完全抗原免疫Wistar大鼠制作EAE大鼠模型,以生理盐水和完全弗氏佐剂注射的Wistar大鼠作为对照。造模成功且存活的大鼠为25只,随机分为4组:MMF大剂量组(30 mg.kg-1.d-1,n=6只),MMF小剂量组(20 mg.kg-1.d-1,n=6只),甲基强的松龙组(30 mg.kg-1.d-1,n=6只),模型组(生理盐水,n=7只),对照组(n=6只)。给予相应药物治疗14 d,每天观察记录神经功能评分,14 d后流式细胞术观察各组血CD4+CD25+T细胞百分数,HE染色观察脑、脊髓组织病理变化。结果 EAE大鼠的造模成功率为0.721。与对照组相比,EAE模型大鼠脑脊髓组织病理学变化主要表现为血管周围有大量炎细胞浸润,神经功能评分明显增加,血CD4+CD25+T细胞百分数明显减少(P<0.01);与模型组相比,用MMF及甲基强的松龙治疗的各组大鼠神经功能评分下降,病理表现有不同程度的减轻,血CD4+CD25+T细胞百分数增加(P<0.01),且大剂量MMF组疗效优于小剂量MMF组和甲基强的松龙组(P<0.01);小剂量MMF组和甲基强的松龙组疗效差异无显著性。结论 MMF可能通过上调CD4+CD25+T细胞比例发挥免疫抑制作用。

Effects of mycophenolate mofetil on blood CD4+CD25+ Tcell of rats with experimental autoimmune encephalomyelitis

Aim To investigate the therapeutic effects of mycophenolate mofetil on blood CD4+ CD25+ T cell of rats with experimental autoimmune encephalomyelitis.Method Wistar rats were induced by guinea pig spinal cord homogenate and Complete Freund Adjuvant to establish EAE models,while control rats were induced by saline and Complete Freund Adjuvant.There were 25 EAE rats which were successfully made and survived.The rats were randomly divided into four groups: high dose of mycophenolate mofetil treatment group(30 mg·kg-1·d-1,n=6),low dose of mycophenolate mofetil treatment group(20 mg·kg-1·d-1,n=6),methylprednisolone treatment group(30 mg·kg-1·d-1,n=6),model group(n=7),control group(n=6).Medicine was administered for 14 days and the rats was assessed by Duckers score every day.After 14 days,the percentage of blood CD4+CD25+ T cells was observed by flow cytometry,the pathological changes of brain and spine cord were observed by Hematoxylin and eosin staining.Result The achievement ratio of EAE model was 0.721.Compared with control group,the pathological changes of EAE rats manifested the inflammatory cells infiltration around vessels with HE staining,Duckers score increased,the number of blood CD4+CD25+ T cells decreased obviously(P<0.01);Compared with model group,after treated with mycophenolate mofetil and methylprednisolone respectively,the Duckers score of EAE rats decreased,the pathological changes lessened and the percentage of blood CD4+CD25+ T cells increased(P<0.01),moreover,the therapeutic effect of high dose mycophenolate mofetil was superior to low dose mycophenolate mofetil and methylprednisolone(P<0.01);there was no obvious difference of the therapeutic effect between low dose mycophenolate mofetil and methylprednisolone.Conclusion Mycophenolate mofetil may affect immune suppression by increasing the percentage of CD4+ CD25+ T cells.