基于腺苷受体2a调控Th17/Treg的补肺益肾方治疗COPD机制

Chronic obstructive pulmonary disease (COPD) is a serious public health problem. Abnormal immune response is regarded to be a vital inducer of lung histopathological destruction. There is strong evidence indicating that inactivation of adenosine receptor 2a (A2aR) and imbalance of Th17/Treg are deeply involved in the abnormal immune response of COPD. Thus, activation of A2aR and restoration of the Th17/Treg balance are valuable approaches to the treatment of COPD. Bufei Yishen formula (BYF) has been proven effective for the treatment of COPD patients. Here, a rat model of cigarette smoke- and bacterial infection-induced COPD is used to investigate the therapeutic mechanisms of BYF on COPD. Flow cytometry is used to detect proportions of Th17 and Treg cells in the peripheral blood, bronchoalveolar lavage fuid, mediastinal lymph nodes and spleen. We then investigate the effects of BYF on the differentiation and function of Th17 and Treg cell. Moreover, We detect the effects of BYF on the expression and activity of A2aR in Th17 and Treg cells. A2aR antagonist and A2aR-specific siRNA are used to evaluate the relative contribution of A2aR in BYF-mediated regulation of the Th17 and Treg cells. Finally, A2aR antagonist and BYF are co-administered to the COPD rats to verify the relevance of the activation of A2aR, the regulation of Th17/Treg cells, and the amelioration of COPD by BYF. Taken together, we evaluate the anti-COPD potential of BYF in COPD rats, and explore its underlying mechanism, with a focus on the regulation of the Th17/Treg imbalance via A2aR, which provide theoretical basis for the clinical application of BYF.

慢性阻塞性肺病（COPD）是危害公众健康的重大疾病。异常免疫应答是引发COPD病理损伤的重要环节，腺苷受体2a（A2aR）活性降低和Th17/Treg失衡在该环节起着关键作用。激活A2aR调控Th17/Treg平衡对治疗COPD具有重要临床意义。基于确证的补肺益肾方治疗COPD的疗效，拟开展研究：①以COPD稳定期大鼠为对象，基于补肺益肾方改善肺组织损伤、肺功能等疗效基础上，应用流式细胞技术观察外周血等Th17和Treg细胞数量及比值变化；②采用血清药理学等方法，研究补肺益肾方对Th17、Treg细胞分化和功能的作用；③研究补肺益肾方调节A2aR表达、活化及与调节Th17/Treg平衡的相关性；④采用拮抗剂，研究该方激活A2aR调节Th17/Treg平衡与其治疗COPD作用的紧密相关性。从“激活A2aR-调控Th17/Treg-抑制异常免疫应答”的新角度，阐明补肺益肾方治疗COPD的机制。

异常免疫应答引发的病理损伤是导致慢性阻塞性肺病（COPD）肺功能持续下降重要因素，腺苷受体2a（A2aR）活性降低和Th17/Treg失衡在该环节起着关键作用。本项目基于确证的补肺益肾方治疗COPD的临床疗效，从激活A2aR活性调控Th17/Treg平衡角度揭示了补肺益肾方治疗COPD机制。研究发现，①补肺益肾方可显著改善COPD大鼠症状，调控Th17/Treg细胞平衡：补肺益肾方高、中、低剂量和氨茶碱均可改善香烟熏吸联合细菌感诱导COPD大鼠的肺组织病理、肺功能、炎细胞浸润、降低相关细胞因子水平；补肺益肾方可降低脾脏和肠系膜淋巴结中Th17细胞比例，升高Treg细胞比例，改善COPD中Th17/Treg失衡情况；补肺益肾方还可调控脾脏组织中Th17、Treg分化功能相关蛋白STAT3、5磷酸化水平。②补肺益肾方可通过激活A2aR诱导Treg细胞分化，抑制Th17细胞分化：建立了TGF-β等细胞因子诱导脾脏幼稚CD4+ T细胞的Th17细胞、Treg细胞分化模型；补肺益肾方可抑制Th17细胞分化，促进Treg细胞分化，以及调控两者相应细胞因子表达。补肺益肾方可上调Th17、Treg细胞中A2aR表达及可显著降低STAT3的磷酸化、升高STAT5的磷酸化水平；A2aR拮抗剂可抑制补肺益肾方调控Th17、Treg细胞分化和细胞因子表达、STAT3、5磷酸化水平的作用。③补肺益肾方可激活A2aR调节Th17/Treg平衡发挥治疗COPD作用：A2aR拮抗剂可抑制补肺益肾方改善COPD大鼠的肺组织病理、肺功能、炎细胞浸润、降低相关细胞因子水平的作用；A2aR拮抗剂还可抑制补肺益肾方可降低脾脏中Th17细胞比例、升高Treg细胞比例、改善COPD中Th17/Treg失衡的作用；A2aR拮抗剂还可抑制补肺益肾方上调脾脏中A2aR的表达及对STAT3/5活化的作用。.综上，本研究证实了补肺益肾方可通过激活A2aR调控Th17/Treg细胞平衡发挥治疗COPD作用，该研究为补肺益肾方临床应用提供依据。