急性肺损伤早期肺常规树突状细胞的动态变化  

The accumulation and maturation status of pulmonary conventional dendritic cells in the early phase of acute lung injury

作　　者：董亮[1] 贺宏丽[1] 刘军[1] 陆晓旻[1] 杨毅[1] 邱海波[1] 

机构地区：[1]东南大学附属中大医院重症医学科,南京210009

出　　处：《中华急诊医学杂志》2012年第6期607-611,共5页Chinese Journal of Emergency Medicine

基　　金：国家自然科学基金（81070049）;江苏省“科教兴卫工程”医学重点学科项目（889-KJXW11.3）;国家临床重点专科建设项目（2100299）;卫生公益性行业科研专项经费项目（201202011）

摘　　要：目的观察急性肺损伤（Au）早期肺常规树突状细胞（cDCs）数量及成熟程度的动态改变及其对Au早期炎症反应和肺损伤的影响。方法C57BL／6小鼠18只随机（随机数字法）分为健康对照组、6h-ALI组和24h-ALI组，气管内注射LPS复制Au模型后6h及24h分别处死小鼠，留取肺组织，采用流式细胞术检测肺cDCs的数量及成熟程度的动态变化；ELISA检测肺组织IL-6、TNF-α水平评价肺部炎症反应；PCR检测肺组织转录因子T—bet及GATA-3mRNA的表达评价Th1／Th2亚群漂移；ELISA检测肺组织IFN-1、IL-4水平反映Th1／Th2型细胞因子的平衡；计算肺湿质量／体质量比评价肺水肿程度；肺组织HE染色行组织病理学检查及肺损伤评分反映肺损伤程度。组间比较采用单因素方差分析。结果AL1组小鼠肺IL-6和TNF-α水平、肺湿质量体质量比及肺损伤评分均较健康对照组显著增高（P〈0．01）；6h-AL1组肺cDCs占肺单个核细胞比例（％）较健康对照组升高[（2．25±0．25）V8（0．93±0．40），P〈0．01]，其肺cDCs表达MHC1／的比例（％）也高于健康对照组[（55．51±11．72）VS．（6．67±0．87），P〈0．01]；而24h—Au组肺cDCs占肺单个核细胞比例（％）较6h．ALI组显著降低[（1．01±0．28）VS．（2．25±0．25），P〈0．01]，其肺cDCs表达MHCII的比例（％）也低于6h-ALI组[（10．94±2．55）VS．（55．514-11．72），P〈0．01]；此外24h-ALI组肺Th1亚群特异性转录因子T—bet相对表达水平较健康对照组升高[（2．94±0．30）vs（1．00±0．12），P〈0．01]，其Th1型细胞因子IFN-γ的水平（Pg·mg^-1）也高于健康对照组[（48．17±0．43）VS（16．46±1．68），P〈0．01]。结论Au早期即存在肺cDCs数量和成熟程度的增加，并可能通过增强Th1型免疫反应及促炎性细胞因子的分泌启动及加剧Au早期肺部炎症反应。Objective To investigate the accumulation and maturation status of pulmonary conventional dendritic cells （cDCs） in the early phase of acute lung injury （ALI）, and to explore the way of the inflammatory responses and lung injury modulated by cDCs in vivo. Methods Male C57BL/6 mice were randomly （random number） divided into the normal control group, 6 h-ALI group and 24 h-ALI group. Murine model of ALI was made by intra-tracheal administration of lipopolysaccharide （LPS） and lung specimens were taken 6 h or 24 h later. The accumulation and maturation status of pulmonary cDCs were assessed by flow cytometry. IL-6 and TNF-α were quantified to evaluate the lung inflammation. Transcription factors T-bet/GATA-3 mRNA ratio was determined to estimate the balance between Thl/Th2 responses. IFN-γ and IL-4 were quantified to evaluate Thl-specific and Th2-specific cytokine production respectively. Lung injury was estimated by lung wet weight/body weight ratio （LWW/BW） and histopathological assessment. Comparison between groups was performed using one -way ANOVA. Results Compared with normal control group, LPS challenge resulted in higher level of IL-6 and TNF-α, increased LWW/BW ratio and significant histopathological changes （P 〈 0. 01 ）. The accumulation and maturation of pulmonary cDCs in 6 h-ALI group were significantly increased after LPS challenge （ P 〈 0.01 ）, while the accumulation and maturation of pulmonary cDCs in 24 h-ALI group were significantly lower than that in 6 h-ALI group （P 〈 0. 01 ）. Compared with normal control group, the expression of T-bet mRNA in 24 h-ALI group was markedly enhanced （ P 〈 0. 01 ） and the production of IFN-γ was increased as well （ P 〈 0.01 ）. Conclusions The accumulation and maturation of pulmonary cDCs peaked within 24 h after LPS challenge, pulmonary cDCs may initiate and amplify acute lung inflammation of ALI by enhancing the Th1 immune response and ensuing cytokine production.

关 键 词：急性肺损伤 常规树突状细胞 成熟 Th免疫应答 细胞因子 炎症 动态变化 

分 类 号：R563.8[医药卫生—呼吸系统]