Treg抑制DC活性调控小鼠肺部炎症发生发展

Regulation of Treg on development of pulmonary inflammation via suppressing activation of dendritic cells in mice

目的探讨调节性T细胞(Treg)在变态反应性肺泡炎中的作用及Treg对变态反应性肺泡炎发生发展过程中树突状细胞(DC)活性影响。方法腹腔注射抗CD25单克隆抗体建立小鼠Treg消除模型,通过气管灌注1-3-β葡聚糖建立小鼠变态反应性肺泡炎模型,采用流式细胞术检测小鼠肺门淋巴结中树突状细胞活性;苏木素-伊红染色进行病理观察,比较各组小鼠肺组织切片中炎症反应和肉芽肿程度。结果与葡聚糖模型组小鼠比较,Treg消除小鼠肺门淋巴结中CD4+CD25+Treg百分比[(6.76±1.0)%]明显降低(P<0.05);组织病理观察显示,Treg消除小鼠肺组织局部炎症反应程度明显重于葡聚糖模型组小鼠;流式细胞术检测发现,葡聚糖灌注后早期,小鼠肺门淋巴结中CD80+MHCII+DC的比例较对照组明显增加;Treg消除小鼠肺门淋巴结和脾细胞中CD80+M HCII+DC比例[(37.3±5.8)%]较葡聚糖模型组小鼠[(24.3±1.9)%]显著升高,差异具有统计学意义(P<0.05)。结论 Treg参与抑制变态反应性肺泡炎的发生发展,其机制可能与抑制DC活性发挥免疫抑制作用有关。

Objective To investigate the role of regulatory T cell（Treg） in allergic alveolitis and the effect of Treg on the activation of dendritic cells （DC） during the development of allergic alveolitis. Methods Intraperitoneal injection of anti-CD25mAb was used to develop Treg depletion model and introtrachea administration of 1-3-β-glucan was used to set up allergic alveolitis model in mice. The activation of DC in hiliar lymph node and spleen was checked with flow cy- tometry. Hematoxylin and eosin staining was used to compare the inflammation and granuloma among different groups. Results Compared with the glucan group, the Treg＇ s percentage in hiliar lymph node in glucan ＋ anti-CD25 group （6. 76±0. 91% ） reduced obviously（P 〈0. 05）. Histological observation showed that the lung inflammation degree in glucan ＋ anti-CD25 mice was significantly higher than that of glucan group. According to the examination of flow cytom- etry, the percentage of CD80 ＋ MHCII ＋ DC in glucan group was increased in the early stage after glucan administration. Meanwhile, the percentage of CD80 ＋ MHCII ＋ DC in glucan ＋ anti-CD25 group in both hiliar lymph node and spleen （37.3 _＋ 5.8 % ） was increased compared with that in glucan group （24. 3 ± 1.9% ）. Conclusion Treg participates in regulating the development of allergic alveolitis through suppressing the activation of DC.