雷帕霉素对哮喘小鼠CD4^+CD25^+调节性T细胞的作用

Effect of rapamycin on CD4^+CD25^+ regulatory T cells in asthmatic mice

目的:建立哮喘小鼠动物模型并给予吸入雷帕霉素治疗,观察雷帕霉素治疗哮喘的效果及其对CD4^+CD25^+调节性T细胞(regulatory T cells,Treg)比例及扩增能力的影响,探讨雷帕霉素治疗哮喘的相关机制。方法:采用随机数字表法将30只雌性BALB/c小鼠分成3组,每组10只,分别为:对照组、模型组和雷帕霉素治疗组。采用Underwood方法对小鼠肺组织进行评分;采用流式细胞术观察小鼠外周血和肺组织中CD4^+CD25^+Treg细胞比例;不同浓度(50、100 nmol/L)雷帕霉素处理小鼠CD4+T细胞后,采用流式细胞术和RT-PCR方法分别检测CD4^+CD25^+Treg细胞形成比例和Foxp3 m RNA表达情况,观察雷帕霉素对小鼠的影响。结果:与模型组相比,雷帕霉素治疗能够显著改善小鼠肺组织病理评分情况;雷帕霉素治疗后,与模型组相比,外周血单个核细胞和肺组织中CD4^+CD25^+Treg均显著升高(P<0.01);50、100 mol/L雷帕霉素处理小鼠CD4+T细胞后,CD4^+CD25^+Treg细胞比例分别为(7.47±1.84)%和(10.93±2.74)%,与对照组[(4.84±0.76)%]相比,雷帕霉素处理可显著促进CD4^+CD25^+Treg细胞增殖(P<0.01);RT-PCR结果与流式细胞结果一致,雷帕霉素处理可显著促进CD4+T细胞中Foxp3的表达(P<0.01)。结论:雷帕霉素可能通过促进CD4^+CD25^+Treg细胞增殖,增加哮喘小鼠外周血和肺组织中CD4^+CD25^+Treg细胞比例,进而对小鼠哮喘发挥治疗作用。

Objective：To investigate the effect of inhaling rapamycin on CD4＋CD25＋ regulatory T cells（Treg） ratio and the treatment of asthma,as well as its related mechanisms,using asthmatic mice treated with inhaled rapamycin therapy. Methods：A total of30 cases of BALB/c mice were random divided into three groups：the control group,the model group,and the rapamycin treatment group,each group had 10 cases. Underwood method was performed to estimate mouse lung tissue scores. CD4＋CD25＋Treg cell ratios of peripheral blood and lung tissues were detected by flow cytometry. Different concentrations（50 and 100 nmol/L） rapamycin were used to treat mice CD4＋T cells,and CD4＋CD25＋Treg cell formation ratio and Foxp3 m RNA expression were analyzed by flow cytom etry and RT-PCR methods. Results ：Compared with the model group, rapamycin treatment significantly improved lung tissue pathology score. CD4＋CD25＋Treg percentage in the model group was（1.94 ± 0.37）% and（2.74 ±0.42）% in peripheral blood mononuclear cells（PBMCs） and lung tissues,respectively,after rapamycin treatment,the CD4＋CD25＋Treg percentage was（5.11±0.64）% and（2.74±0.42）% in PBMCs and lung tissues,respectively. After treated with different concentrations of rapamycin,CD4＋CD25＋Treg ratio in the control group was（4.84 ± 0.76）%,and in the 50 nmol/L and the 100 nmol/L rapamycin groups was（7.47±1.84）% and（10.93±2.74）%,respectively. RT-PCR results were consistent with the results of flow cytometry staining,rapamycin treatment significantly promoted CD4 T cells Foxp3 expression（P〈0.01）. Conclusion：By promoting CD4＋CD25＋ Treg cell proliferation,rapamycin can increase CD4＋CD25＋Treg cell ratio of peripheral blood and lung tissues in asthmatic mice,and thus exert a therapeutic effect on asthma.