MRL/lpr狼疮小鼠CD4^+ CD25^+调节性T细胞和相关基因的研究

The study of CD4^+ CD25^+ regulatory T cells and target genes in thymus and spleen of MRL/lpr mice

目的通过研究MRL/lpr系统性红斑狼疮(SLE)小鼠(模型组)胸腺、脾脏中CD4+ CD25+调节性T细胞(Tr)数量和相关基因的变化,探讨Tr在SLE发病中的作用。方法采用间接免疫荧光法检测模型组和对照组血清中抗核抗体水平,流式细胞术检测胸腺、脾脏中Tr数量,RT-PCR检测Tr功能基因表达水平。结果抗核抗体模型组均为阳性,而对照组均为阴性;胸腺、脾脏中Tr数量模型组与对照组无明显差别;Foxp3的表达水平在模型组胸腺中与对照组无明显差别,而在模型组脾脏中却低于对照组;CTLA-4的表达水平在模型组胸腺和脾脏均高于对照组。结论Tr数量的变化在MRL/lpr小鼠的发病中不起关键作用,而Tr功能的变化,尤其在外周的功能缺陷可能是其发病的原因之一,至于Tr的抑制功能是否真正发生变化,还有待于进一步通过体外抑制功能的检测来确定。

Objective To investigate CD4＋CD25＋ regulatory T cells and target genes in thymus and spleen of MRL/lpr mice. Methods Serum anti-nuclear antibody was detected by indirect immunofluorescence. CD4＋CD25＋Tr was determined by flow cytometry and its target genes were detected by RT-PCR. Results Anti-nuclear antibody was positive in model group but negative in control group. There were no significant differences of CD4＋CD25＋Tr in model and control groups. Foxp3 levels of model group was no significant difference in thymus but lower in spleen compared with that of control group. CTLA-4 levels of model group had higher than those of control group both in thymus and in spleen. Conclusions MRL/lpr mice do not occur as a result of reduced level of CD4＋CD25＋Tr,but function defect of CD4＋CD25＋Tr may be responsible for its occurrence. But the suppressive effect of CD4＋CD25＋Tr is still need to be confirmed by vitro test.