肺组织 Treg 细胞反应性降低加重 LPS 诱导的老龄小鼠急性肺损伤

Decreased response of Treg cell may be associated with increased inflammatory reaction in LPS-induced acute lung inj ury in aging mice

目的：本研究旨在对老龄和年轻小鼠 ALI 病理变化过程中 Treg （regulatory T cell, Treg）细胞的变化进行观察,以期进一步揭示老龄鼠肺组织损伤和修复的机制。方法使用3~4月龄和18~22月龄雄性 C57BL/6小鼠,通过气管内给药建立脂多糖（LPS）诱导 ALI 模型,分别观察两组小鼠在肺损伤急性炎症期和损伤修复期的病理表现。取造模后1、3、5、7和10 d 小鼠 BALF 和肺组织单细胞悬液,流式细胞术检测 Treg 细胞百分比变化。结果在肺损伤急性炎症期,与年轻小鼠相比,老龄小鼠 BALF 及肺组织中 Treg 细胞反应均明显低于年轻小鼠。在肺损伤的修复期,老龄小鼠 BALF 和肺组织内 Treg 细胞的百分比和绝对值仍低于年轻小鼠。结论本研究结果提示,经 LPS刺激后老龄小鼠 Treg 细胞反应性降低,同时伴随老龄小鼠炎症反应加重。

Objective To investigate the changes of regulatory T （Treg） cell population and the pathological changes during acute lung injury in elderly mice compared with young mice,which might further reveal the mechanism of lung tissue damage and repair in aging mice.Methods LPS-induced acute lung injury models were established in 3-4 （young adult group）and 18-22 months old male C57BL/6 mice （aging group） by intratracheal administration LPS.Inflammatory changes were analyzed with H＆amp;E histological staining at days 1,3,5,7 and 10,respectively.Flow cytometry was employed to analyze percentages of regulatory T cells in bronchial alveolar lavage fluid（BALF）and lung tissue cell suspension at above time points.Results At the acute inflammation phase of lung injury,percentages of Treg in BALF and lung tissue were significantly lower in aging mice than that of young mice.At the repairing phase,percentages and absolute numbers of Treg in aging mice were still lower than that of young mice. Conclusions Our datas suggest that response of Treg decreases in LPS-induced acute lung injury in aging mice,which might be associated with increased inflammatory reaction in aging mice.