IL-7对诱导型Tregs表型及功能的影响

Effects of IL-7 on the phenotype and function of inducible Tregs

目的初步探讨IL-7对C57BL/6小鼠脾细胞诱导CD4^+CD25^+调节T细胞(iTregs)的表型及功能的影响。方法采用磁珠分选技术分选出小鼠CD4^+CD25^-T细胞,体外环境下给予anti-CD3、anti-CD28、TGF-β、IL-2和维甲酸共同诱导7d,生成CD4^+CD25^+调节T细胞(iTregs),流式细胞术分析经IL-7刺激24 h后iTreg的表型变化,同时用CFSE稀释法观察其对iTreg细胞抑制功能的影响。结果CD4^+CD25-T细胞通过anti-CD3、anti-CD28、TGF-β、IL-2和维甲酸共同作用,成功诱导为CD4^+CD25^+iTregs;通过10 ng/ml IL-7干预刺激,iTregs的CD39(P=0.0007)和CTLA-4(P=0.0110)表面分子表达显著下降,iTregs凋亡显著增加(P=0.0020),抑制功能显著减弱(P=0.0013)。结论在高质量浓度IL-7的环境中,iTregs抑制功能明显下降且更易于凋亡,说明体外大量诱导的iTregs应用于高质量浓度IL-7机体中,可能是无法达到理想治疗效果的原因之一。

Previous study confirmed that serum IL-7 level is correlated with the severity of acute GVHD. This study designed to study the effects of IL-7 on the phenotype and function of inducible regulatory T cells （iTregs）. CD4＋CD25- T cells were isolated from spleen of C57BL/6 mice by magnetic activated cell sorting （MACS）, then the ceils were induced in vitro with anti-CD3, anti-CD28, TGF-[3, IL-2 and retinoic acid for 7 days until cells expressed CD4＋CD25＋, defined as iTregs. Then the phenotype and suppressive activity of iTregs were analyzed by flow cytometry after be stimulated with IL-7 for 24 h. The expressions of CD39 （P=0.000 7） and CTLA-4 （P=0.011 0） of iTregs were significantly decreased after 10 ng/ml IL-7 intervention, and the suppressive activity of iTregs was also significantly decreased （P=0.001 3）, furthermore, the apoptosis of iTregs was significantly increased （P=0.002 0）. These combined data suggested that the suppressive activity of iTregs was obviously decreased in the environment of high concentration IL-7, which indicates that iTregs therapy may not achieve the desired effect in patients of immune disorders with internal environment of high concentration IL-7.