香烟烟雾暴露小鼠中CD4+Foxp3+调节性T细胞中组蛋白去乙酰化酶的表达及意义

摘要

Objective:To evaluate the expression of histone deacetylase(HDAC) in CD4+ Foxp3+ regulatory T(Treg) cells and the function in cigarette smoke-induced emphysema mice.Methods:40 male Balb/c mice were randomly divided into control group,trichostatin A(TSA,a HDAC inhibitor) group,smoke exposure (SE) group and SE+TSA group,with 10 mice in each group.Morphological changes of lung tissues were observed by hematoxylin eosin(HE) staining.The mRNA expressions of HDAC2,HDAC5,HDAC7 and HDAC9 were determined by qPCR.The expression of cytotoxic T lymphocyte associated antigen-4(CTLA-4) in Treg cells,the proliferation ability of Treg cells and its inhibitory effect on the Teff cells proliferation were detected by flow cytometry.Results:The mean linear intercepts(MLI) was higher in the SE group than that in the control group(P＜0.05),suggesting that the mice emphysema model was successfully established.The HDAC2,HDAC5,HDAC7 and HDAC9 mRNA levels and the Teff cells proliferation rate were significantly decreased,while the positive expression rate of CTLA-4 in the Treg cells and the proliferation rate of Treg cells were increased in SE group and TSA group,compared with the control group(P＜0.05).The positive rate of CT-LA-4 expression,the proliferation ability of Treg cells and its inhibitory effect on the Teff cells proliferation were enhanced by the treatment of TSA in SE mice (P ＜ 0.05).Conclusion:The expression of HDAC in CD4+ Foxp3+ Treg cells was down-regulated in cigarette smoke-induced emphysema mice.HDAC might be involved in the immune imbalance of Treg cells induced by smoking.%目的:探讨香烟烟雾暴露小鼠CD4+ Foxp3+调节性T细胞(Treg细胞)中组蛋白去乙酰化酶(HDAC)的表达及意义.方法:将40只健康的雄性Balb/c小鼠随机分为对照组、HDAC阻滞剂曲古菌素A(TSA)组、烟熏组、烟熏+TSA组.烟熏组香烟烟雾暴露24周建立小鼠肺气肿模型,苏木精伊红(HE)染色观察小鼠肺组织形态学改变.免疫磁珠分选纯度大于90％的Treg细胞,实时荧光定量PCR(qPCR)法检测Treg细胞中HDAC2、HDAC5、HDAC7、HDAC9等mRNA表达水平.流式细胞术检测Treg细胞中表达细胞毒性T淋巴细胞抗原4(CTLA-4)的比率、Treg增殖能力及其对效应Teff细胞增殖抑制作用.结果:烟熏组的平均内衬间隔(MLI)为(53.1±8.7)μm,明显高于对照组的(28.2±1.2)μm(P＜0.05),成功建立肺气肿模型.与对照组比较,TSA组和烟熏组Treg细胞HDAC2、HDAC5、HDAC7、HDAC9 mRNA相对表达量降低,Treg细胞中CTLA-4表达率及其分裂指数升高,Teff细胞分裂指数下降(P＜0.05);加入TSA进行体外干预后,与烟熏组比较,烟熏+TSA组Treg细胞CTLA-4表达率升高,Treg细胞增殖能力及对效应Teff细胞的增殖抑制作用均增强(P＜0.05).结论:在香烟烟雾诱导的肺气肿小鼠中,CD4+ Foxp3+ Treg细胞HDAC表达下降,HDAC可能参与吸烟所致的Treg细胞免疫功能失衡.