IL-17A对小鼠气管移植后早期气道上皮细胞的影响

The role of IL-17A in airway epithelium during tracheal transplantation

目的 通过建立小鼠原位气管移植模型,探讨气管移植早期IL-17A对气道上皮细胞的影响.方法 选取19～ 21 g清洁级雄性C57BL/6小鼠（n=50）和BALB/c小鼠（n=20）,供受体按体质量配对后随机分为5组,对照组：正常C57BL/6小鼠（n=10）;A组：C57 BL/6（n=10） →C57BL/6（n=10）;B组：BALB/c（n=10） →C57 BL/6（n=10）;C组：BALB/c（n=5）→C57 BL/6（n=5）,注射anti-IL-17A中和抗体;D组：BALB/c（n=5）→C57 BL/6（n=5）,注射IgG;A、B组进一步随机分为3天、14天亚组（n=5）.术后第3天,采用实时荧光定量PCR技术检测A、B组移植气管中IL-17A mRNAⅡ表达水平,使用流式细胞技术检测气管引流淋巴结中γδ T细胞的比例.术后第14天,分别采用HE、Masson染色,观察各组移植气管组织病理学改变.结果 术后小鼠无死亡.术后第3天,B组移植气管组织中IL-17AmRNA表达水平明显高于A组（P＜0.05）;B组小鼠气管引流淋巴结中γδ T细胞占CD3＋T细胞的比例明显高于A组（P＜0.05）.术后14天移植气管组织病理学检查提示：A组气道纤毛柱状上皮结构完整,黏膜下层无纤维组织增生;B、D组气道上皮由柱状变为扁平状上皮并部分脱落,黏膜下层纤维组织增生明显;C组气道纤毛柱状上皮结构较完整,黏膜下层可见纤维组织增生.4组小鼠气管管腔闭塞率分别为（31.21 ±2.82）％、（42.45±2.21）％、（39.04±1.98）％、（40.67±1.54）％,A、B组相比差异有统计学意义（P＜0.05）.结论 IL-17A在气管移植免疫排斥的早期发挥重要作用,并介导气道上皮的损伤.

Objective We used the murine orthotopic tracheal transplantation model to study the role of IL-17A in posttransplant airway epithelium.Methods Pathogen-free male C57BL/6 （n =50） and BALB/c （n =20） weighing 19-21 g.Weight-matched mice were randomly assigned to 5 groups.Control group：normal C57BL/6 （n =10） ; Group A：C57BL/6 （n =10） → C57BL/6（n =10）,Group B：BALB/c（n =10） → C57BL/6（n =10）,Group C：BALB/c（n =5） → C57BL/6 （n =5） and receive anti-IL-17 A neutralizing antibody injections,Group D：BALB/c （n =5） → C57 BL/6 （n =5） and receive IgG antibody injections.Group A and group B were randomly divided into 3 days and 14 days two subgroups（n =5）.The expression level of IL-17A mRNA in tracheal of group A and group B was detected by real time quantitative PCR at 3 days after transplantation,and the frequencies of γδ T cells in draining lymph nodes of tracheal were analyzed by flow cytometry.Histopathological changes of tracheal were observed by HE staining and Masson staining at 14 days after transplantation.Results The mortality was 0 after tracheal transplantation.At the 3rd day,the IL-17A mRNA level of group B increased significantly as compared with group A（P 〈 0.05）,and the percent of γδ T cells among CD3 ＋ T cells of group B was higher than group A（P 〈 0.05）.At the 14th day,the airway epithelia of group A maintained normal pseudostratified epithelium,and proliferation of fibroblast in submucosa tissue was not observed.The airway pseudostratifie epithelia of group B and D changed into flat epithelium,and proliferation of fibroblast was observed.The airway epithelia of group C preserved a pseudostratified epithelium,and proliferation of fibroblast was observed.The percentage of luminal obliteration of 4 groups was （31.21 ± 2.82） %、（42.45 ± 2.21） %、（39.04 ± 1.98） %、（40.67 ±1.54） % respectively.The percentage of luminal obliteration of group B was higher than group A（P 〈 0.05）.Conclusion IL-17A plays an important role at the early stage of tracheal allograft rejection and mediates airway epithelial lesion.