调节性T细胞在烟熏诱导的小鼠肺气肿模型中的变化及意义

Change and Significance of Regulatory T Cells in Emphysema Model Mice Induced by Smoking

目的:研究CD4^+Foxp3^+调节性T细胞在烟熏诱导的小鼠肺气肿模型中的变化并探讨其意义。方法:6-8周龄C57BL/6FoxP3-GFP knock-in小鼠18只,按照随机对照方法分为吸烟组(S组)和非吸烟组(NS组),将吸烟组小鼠暴露自制烟熏箱里,每天烟熏4h,每周烟熏5d,连续24周建立小鼠肺气肿模型,正常对照组小鼠置入空气清洁的房间。24周后取两组小鼠的肺组织进行HE染色评价肺气肿,同时通过流式细胞术检测小鼠支气管肺泡灌洗液、肺组织、纵隔淋巴结、脾脏中Treg细胞、CD4^+T细胞、CD8^+T细胞、CD4^+CD69^+T细胞、CD8^+CD69^+T细胞的数量变化。结果:与非吸烟鼠相比,烟熏24周后吸烟鼠肺组织的病理染色可见典型肺气肿表现;吸烟鼠肺组织、支气管肺泡灌洗液及纵隔淋巴结中Treg细胞、CD4^+T细胞、CD8^+T细胞及其活化细胞(即CD4^+CD69^+T细胞和CD8^+CD69^+T细胞)的数量明显高于非吸烟鼠,差异有统计学意义(P<0.05),而上述细胞在两组小鼠的脾脏中的数量无明显差异(P>0.05)。结论:吸烟鼠肺组织、支气管肺泡灌洗液及纵隔淋巴结中Treg细胞、CD4^+T细胞、CD8^+T细胞及其活化细胞的数量明显高于非吸烟鼠,提示小鼠肺气肿模型中存在将累及肺组织及其周围组织的异常炎症反应,而淋巴细胞可能在其中发挥了重要作用,而由于Treg细胞相对不足或功能障碍使其不能正常发挥免疫调节作用。

Objective:To investigate the change and significance of CD4^+Foxp3^+regulatory T Cells in emphysema model mice induced by smoking.Methods:A total of 18Foxp3-GFP knock-in C57BL/6mice aged 6-8weeks were randomly divided into smoke-exposure group and non smoke-exposure group.The mice of smoke-exposure group were exposed to cigarette smoke for 24weeks(4hours every day,5days every week),while the mice of non smoke-exposure group were exposed to clean air.The lungs of both groups were taken for HE staining to evaluate emphysema after 24 weeks.The proportions of CD4^+T cells,CD8^+T cells,CD4^+CD69^+T cells,CD8^+CD69^+T cells and regulatory T cells(CD4^+Foxp3^+T cells)in the lungs,bronchoalveolar lavage fluid,mediastinal lymph nodes and spleen were examined by flow cytometry.Results:Compared to micein non smoke-exposure group,typical emphysema was seen in the lungs of mice in smoke-exposure group.The proportions of regulatory T cells,CD4^+T cells,CD8^+T cells,CD4^+CD69^+T cells and CD8^+CD69^+T cells in the lungs,bronchoalveolar lavage fluid and mediastinal lymph nodes of mice in smoke-exposure group were significantly increased as compared with those in non smoke-exposure group(P<0.05),while there was no difference in proportions of these cells in the spleen between the two groups(P>0.05).Conclusion:The results illustrated that an abnormal inflammatory response in mice of emphysema model,and lymphocytes played an important role in inflammatory response.However,the regulatory T-cells could not play their normal immune regulation role due to relative lack or functional impairment.