肺移植术后早期移植气管的病理学改变及γδT细胞变化的研究

Changes of histopathology and γδ T cells at early stage of post lung transplantation

目的:建立同种同型小鼠原位气管移植模型,模拟并观察肺移植手术早期移植气管的病理学改变和固有γδT细胞的动态变化。方法:雄性C57BL/6小鼠(n=45),随机分为对照组(n=15)和实验组(n=30),各组又随机分为1天、3天、5天三个亚组。对实验组小鼠建立原位气管移植模型,术后第1,3,5天对两组小鼠行肺功能检查、肺泡灌洗液行总细胞计数及分类、移植气管组织病理学检查,使用流式细胞技术检测气管引流淋巴结中γδT细胞的比例,并采用实时荧光定量PCR技术检测移植气管组织中IL-17A基因表达水平。结果:与对照组比较,实验组术后第3,5天的肺总阻力明显增高(P<0.05);实验组肺泡灌洗液中总细胞计数均显著增加(P<0.05),且以巨噬细胞和中性粒细胞为主;实验组术后气管黏膜下层水肿;实验组术后第1,3天小鼠气管引流淋巴结中γδT细胞占CD3+T细胞的比例明显高于对照组[1天:(2.66±0.19)vs.(1.82±0.13)%;3天:(2.33±0.07)vs.(1.82±0.16)%];与对照组相比,实验组中所有亚组IL-17A mRNA的表达量明显增加(P<0.05)。结论:同种同型小鼠气管移植手术创伤,可激活γδT细胞等固有免疫细胞,其中γδT细胞可能通过分泌IL-17A进一步募集巨噬细胞和中性粒细胞,加剧移植术后的炎性反应,导致移植气管黏膜下层水肿。

Objective： C57BL/6 donor tracheal segments were orthotopically transplanted into syngene- ic C57BL/6 recipients. Investigate changes of histopathology andγθT cells at early stage of this model. Meth- ods： The male C57BL/6 mice （n =45） were randomly divided into two groups： control group （n = 15） and ex- periment group （n = 30）. The survival mice were randomly divided into lday, 3day and 14day three sub- groups. Orthotopie trachea transplantion was performed in the experiment group. Changes in pulmonary function were measured on the 1 day, 3 day and 5 day after tracheal transplantion. Bronchoalveolar Lavage Fluid （BALF） was collected and classified. Histopathological changes of tracheal were observed by HE staining. The frequencies of γθT cells in draining lymph nodes of trachea were analyzed by flow cytometry. The expression level of IL-17A mRNA in tracheal was quantitatively detected by real time quantitative PCR. Results： The pul- monary resistance of experiment group increased on the day 3 and day 5 of post-operation compared to control group （ P 〈 0. 05 ）. Total cell count in BALF was increased in experiment group, mainly macrophages and neu- trophils. On the day 1 or day 3 after the operation the percent of γθ T cells in CD3 ＊ T cells in experiment group in mouse draining lymph node was higher than that in control group[ 1 day： （2. 66 ＋0. 19） vs. （1.82 ＋0. 13） % ; 3 day ： （2. 33 ＋ 0. 07） vs. （ 1.82 ＋ 0. 16） % , The expression level of IL-17A mRNA in experiment group was increased as compared with that in control group. Conclusion： In the orthotopic trachea transplantion mod-el in mice, surigical trauma activated γθ T cells, and γθ T cells might secrete IL-17A, making macrophages and neutrophils gathered and expending inflammation, resulting in the submucosa tissue edema.