南方医科大学学报

南方医科大学学报 ›› 2021, Vol. 41 ›› Issue (5): 716-721.doi: 10.12122/j.issn.1673-4254.2021.05.12

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芳香烃受体通过介导Th17/Treg分化调控蟑螂过敏原诱导的哮喘

许 婷，崔 壮，王俊洁，冯 媛，谢 仁，李丹青，彭 婧，黄 蓉，李涛平   

  • 出版日期:2021-05-20 发布日期:2021-06-11

Aryl hydrocarbon receptor modulates airway inflammation in mice with cockroach allergen-induced asthma by regulating Th17/Treg differentiation

  • Online:2021-05-20 Published:2021-06-11

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摘要： 探讨芳香烃受体（AhR）是否能够通过介导肺内Th17/Treg细胞的分化来调控蟑螂过敏原（CRE）诱导的哮喘。方法 通过蟑螂过敏原激发和致敏，建立哮喘小鼠模型。部分哮喘小鼠给予 AhR 激动剂（TCDD）(10 μg/kg)或 AhR 拮抗剂（CH223191）（10 mg/kg）刺激。实验小鼠分为4组：对照组、哮喘组（CRE）、AhR激活组（CRE+TCDD）及AhR拮抗组（CRE+TCDD+CH223191）。通过RT-PCR检测哮喘小鼠肺内AhR及其下游Cyp1a1和Cyp1b1基因的表达；免疫组化染色观察哮喘小鼠肺内炎症变化；酶联免疫吸附试验（ELISA）监测炎症细胞因子的表达；采用流式细胞术检测肺及纵膈淋巴结中Treg的表达。结果 TCDD和CH223191能够调控哮喘小鼠肺内AhR及其下游基因Cyp1a1和Cyp1b1的表达（P<0.002）；AhR激活后肺内炎症细胞及粘液分泌较CRE组减少，促炎因子IL-4、IL-13和Th17A表达减少（P<0.001），而抑炎因子IL-10、IL-22和TGFβ1表达增加（P<0.001），而拮抗AhR后逆转了这一现象，且与CRE组无统计学差异（P>0.05）；AhR激活后肺及纵膈淋巴结中Treg细胞及其转录因子FOXP3表达明显增加（P<0.001），Th17细胞转录因子RORγt基因表达水平明显降低（P<0.001），而拮抗AhR后，与激活组相比，肺及纵膈淋巴结中CD4+CD25+Foxp3+Treg细胞及其转录因子FOXP3表达减少（P<0.001），RORγt基因表达水平增加（P<0.001）；与CRE组相比，差别无统计学意义（P>0.05）。结论 AhR通过介导Th17/Treg细胞分化来调控哮喘小鼠肺部炎症。

关键词: 芳香烃受体；蟑螂过敏原；哮喘；Th17；调节T细胞

Abstract: Objective To investigate whether aryl hydrocarbon receptor (AhR) modulates cockroach allergen (CRE)-induced asthma by regulating Th17/Treg differentiation. Methods Mouse models of CRE-induced asthma established by sensitizing and challenging the mice with CRE were randomized into asthma model group, AhR agonist group treated with TCDD (10 μg/kg), and AhR antagonist group treated with TCDD and CH223191 (10 mg/kg) (n=5), with 5 mice without CRE challenge as the control group. The expressions of AhR, Cyp1a1 and Cyp1b1 mRNA in the lung tissues of the mice were detected using RT-PCR, and pulmonary inflammation was evaluated with immumohistochemical staining. The expressions of inflammatory cytokines in the lungs were detected using ELISA, and the expression of Treg in the lung tissues and pulmonary lymph nodes was analyzed with flow cytometry. Results Both TCDD and CH223191 were capable of modulating pulmonary expressions of AhR and its downstream genes Cyp1a1 and Cyp1b1 in asthmatic mice (P<0.002). TCDD treatment significantly decreased inflammatory cells and mucus production in the lungs of asthmatic mice, and BALFs from TCDD- treated mice with CRE challenge contained lowered levels of the proinflammatory factors including IL-4, IL-13 and IL-17A (P<0.001) but increased anti- inflammatory factors including IL-10, IL-22 and TGF-β1 (P<0.001). All these changes were significantly reversed by treatment with CH223191 to the levels comparable with those in the asthma model group (P>0.05). More importantly, TCDD treatment significantly increased the number of Tregs cells and FOXP3 expression and lowered RORγt mRNA expression in the lungs and pulmonary lymph nodes in asthmatic mice (P<0.001); inhibition of AhR with CH223191, as compared with TCDD, significantly decreased the expression of CD4+CD25+Foxp3+Treg cells in the lungs and pulmonary lymph nodes and the expression of FOXP3 mRNA in lymphocytes and increased RORγt mRNA expression (P<0.001) to the levels comparable with those in asthma model group (P>0.05). Conclusion AhR activation modulates airway inflammation in mice with CRE-induced asthma by modulating the differentiation of Th17/Treg.

Key words: Aryl hydrocarbon receptor; cockroach allergen; asthma; Th17; Treg