Role of Eosinophils in Airway Inflammation and Remodeling

描述(申请人提供)：呼吸道嗜酸性粒细胞增多症是哮喘严重程度、恶化风险和治疗反应的重要标志。根据目前对嗜酸性粒细胞(EOS)功能的了解，在前一个资金周期完成的初步数据和研究，形成了EOS通过促进气道炎症和重塑在哮喘病理生理学中发挥关键作用的假设的基础。PPG续展申请中的研究旨在回答临床上重要的问题，以最大限度地利用我们的集体专业知识和资源。它们将使我们能够批判性地、全面地和交互地解决EOS在过敏性呼吸道炎症中的作用 在人体内和体外的实验中，适当地，通过集中使用细胞系和动物模型来补充。项目1将研究EOS的关键功能，包括通过表达SEMA7A促进IL-17反应和增强成纤维细胞(FB)功能，从而促进myoFb分化和细胞外基质(ECM)成分的生成。哮喘气道中Th2失衡的环境促进了Periostin的表达，Periostin是过敏性炎症的重要标志。项目2中提议的研究将确定这种ECM蛋白如何与EOS相互作用，以增强它们的生存、介质释放和对EOS活性细胞因子的反应。研究将确定在呼吸道中产生Periostin的要求以及EOS整合素αMBeta2识别的要求。最后，在项目3中，将研究促纤维化细胞因子、转化生长因子-β1信号在EOS和FB中的分子机制，重点是Pin1与近端Smads以及PI-3-K和Akt的相互作用。我们的研究小组发现，异构酶Pin1的上调是转化生长因子-β1信号通路中的关键步骤，并试图确定Pin1是如何影响Smad6和Smad3的，包括Akt和PI-3-KGamma在这一过程中的作用。可以说，世界上几乎没有其他中心能够进行恢复气道EOS所需的临床研究，同时拥有必要的经验来批判性地剖析EOS生物学功能，达到我们团队能够做的相同复杂程度。三个实验室的合作研究和丰富的临床研究经验将使我们能够从体外实验到体内实验来回移动，以更好地了解EOS在调节过敏性气道炎症和重塑中的作用。鉴于嗜酸性炎症在相当大比例的严重哮喘患者中的突出表现，这些进展将对受这种非常常见疾病影响最大的患者产生直接影响。

DESCRIPTION (provided by applicant): Airway eosinophilia is an important marker of asthma severity, risk of exacerbation, and response to therapy. Based upon the current understanding of the function of eosinophils (EOS), the preliminary data and studies accomplished over the previous funding cycle, form the basis for the hypothesis that EOS play a pivotal role in asthma pathophysiology by enhancing airway inflammation and remodeling. The studies in this PPG renewal application are designed to answer clinically important questions formulated to take maximum advantage of our collective expertise and resources. They will allow us to address critically, comprehensively and interactively the role of EOS in allergic airway inflammation using ex vivo and in vivo experiments in human subjects complemented, as appropriate, by focused use of cell lines and animal models. Project 1 will investigate key EOS functions including promoting IL-17 responses and enhancing fibroblast (Fb) function via expression of SEMA7A, which leads to promoting myoFb differentiation and generation of extracellular matrix (ECM) components. The Th2 skewed environment in the asthmatic airway promotes the expression of periostin, an important marker of allergic inflammation. The proposed studies in Project 2 will determine how this ECM protein interacts with EOS to enhance their survival, mediator release, and response to EOS-active cytokines. Studies will define the requirements for periostin generation in the airway and recognition by the EOS integrin alphaMBeta2. Finally in Project 3, the molecular mechanisms regulating the pro-fibrotic cytokine, TGF-Beta1 signaling in EOS and Fb will be investigated focusing on the role of Pin1 interaction with proximal Smads as well as PI-3-K and Akt. Our group discovered that up-regulation of isomerase Pin1 is an essential step in the TGF-Beta1 signaling pathway and seek to determine how Pin1 influences Smad6 and Smad3 including the role of Akt and PI-3-Kgamma in this process. It can be argued that few other centers, if any, around the world are capable of doing the clinical studies needed to retrieve airway EOS and at the same time have the experience necessary to critically dissect EOS biological functions to the same level of sophistication that our group is capable of doing. The collaborative studies among the three laboratories and the rich clinical research experience will allow us to move back and forth from ex vivo to in vivo experiments to better understand the role of EOS in modulating allergic airway inflammation and remodeling. Given the prominence of eosinophilic inflammation in a significant proportion of severe asthma patients, these advances will have direct implications for the patients most affected by this very common illness.