异基因骨髓间充质干细胞移植对胶原诱导性关节炎大鼠的免疫调节作用

The immunomodulatory effect of allogenic mesenchymal stem cell transplantation on rats with coll- agen induced arthritis

目的 通过对类风湿关节炎（RA）动物模型胶原诱导性关节炎（CIA）大鼠的实验研究,观察异基因骨髓间充质干细胞（MSCs）移植对早期、晚期CIA大鼠免疫细胞和分子的免疫学作用,并探讨其在体内发挥免疫调节作用的机制.方法 采用密度梯度离心结合贴壁培养法体外分离、培养大鼠MSCs,细胞表型鉴定;建立CIA大鼠模型;MSCs移植均采用尾静脉注射,移植后第42天全部处死动物取脾,通过实时定量-聚合酶链反应（RT-PCR）测定Foxp3 mRNA的表达水平,流式细胞术测定CD4＋CD25＋调节性T细胞的变化.采用单因素方差分析、LSD-t检验法进行统计学分析.结果 早期、晚期CIA对照组CD4＋CD25＋调节性T细胞（1.6±0.6,1.4±0.6）和Foxp3 mRNA（0.88±0.20,0.91±0.12）的表达水平低于健康组和治疗组,差异有统计学意义（P＜0.05）,早期治疗组CD4＋CD25＋调节性T细胞（5.0±0.4）比晚期治疗组（3.9±0.4）有所升高,差异有统计学意义（P＜0.05）.结论 异基因MSCs移植可通过上调CIA大鼠体内CD4＋CD25＋调节性T细胞水平,促进Foxp3 mRNA的表达而发挥其在体内的免疫调节作用,早期治疗组的疗效优于晚期治疗组.

Objective To observe the immunologic effect of transplantation of MSCs by studying the early and later period of collagen induced arthritis. Methods Rats MSCs were isolated and expanded from bone marrow cells by density gradient centrifugation and adhering to the culture plastic bottle, and the phenotypes were assessed by flow cytometry. We established collagen induced arthritis rats model. MSCs wereinjected from tail veins. We observed the expression of Foxp3 mRNA using RT-PCR, and the level of CD4＋CD25＋ T cell was tested by flow cytometry. One-way ANOVA and LSD-t test were used for statistical analysis.Results The percentage of CD4＋ CD25＋ T cells in early and later CIA groups was lower than that of normal control group and treatment groups, which showed statistically significant difference （P〈0.05）. The level of CD4＋ CD25＋ T cell in early MSCs treatment group was higher than the later MSNs treatment group, which showed statistically significant difference （P〈0.05）. Compared to the normal group and treatment groups, the expression level of Foxp3 mRNA in the early and later CIA groups was decreased markedly, while the early MSNs treatment group versus the later treatment group showed no statistically significant difference （P〉0.05）.The intensity of Foxp3 mRNA in the treatment groups was similar to normal control group. Conclusion In this study, MSCs has shown significant immune-modulatory effects. It up-regulates the level of CD4＋ CD25＋ T cell in CIA rats, accelerate the expression of Foxp3 mRNA. The early treatment group is more effective than the late treatment group.