Origin and Function of Intra-epithelial Mast Cells in Asthma

项目摘要 呼吸道高反应性(AHR)是哮喘的一个基本特征，也是该疾病在 大多数哮喘患者。我们的实验室一直在努力了解潜在的 AHR的免疫发病机制及其新近发现的三维定量成像 气道壁：哮喘患者肥大细胞(MC)S从粘膜下层向呼吸道上皮细胞转移 与AHR的严重程度以及2型(T2)炎症的特征密切相关。这一转变至关重要，因为 我们发现了一个依赖于IL-33的前馈环，在这个环中，MC调节上皮细胞IL-33的表达 (IL-33)，表明MC不仅作为效应细胞发挥作用，而且通过IL-33调节T2炎症。 这种前馈环路在哮喘患者的呼吸道上皮细胞S中被强调，表明 哮喘上皮细胞建立的独特微环境对哮喘的繁殖至关重要。 通过MCs和呼吸道上皮之间的这种前馈相互作用，AHR和T2炎症的发生。 本研究的主要目的是确定MC在呼吸道中渗透的潜在基础。 上皮，系膜细胞与个体原代血管内皮细胞相互作用的分子细节 使用选定的哮喘小鼠模型，研究IL-33-MC轴与哮喘的体内相关性。 鉴于成熟的MC起源于循环中的祖细胞，我们假设MC祖细胞的数量 哮喘患者呼吸道中单核细胞趋化蛋白S增多，这些细胞与易感气道协同发挥作用 上皮细胞来协调T2炎症。我们将通过使用呼吸道样本直接解决我们的假设 和来自有或没有哮喘和/或过敏性敏感者的原代AEC，与AEC- MC共培养模型，以及我们检测IL-33-MC轴功能的哮喘小鼠模型。在……里面 具体目标1，我们研究了MCP在呼吸道中的数量和增殖能力的差异 哮喘和AHR受试者的外周血与非哮喘对照组和 无过敏反应。我们进一步研究了变应原后MCP在呼吸道中的扩张。 对哮喘患者的挑战。在特定的目标2中，我们确定哮喘的呼吸道上皮是如何 使用来自患有和的受试者的原代AEC的体外模型，与MCs相互作用以调节T2炎症 没有哮喘来检查这种前馈机制。在特定目标3中，我们使用选择性IL-33受体 体内模型中巨噬细胞中的缺失，以了解IL-33如何通过巨噬细胞调节巨噬细胞的发育 T2炎症和AHR。使用呼吸道样本、AEC表型和 复杂的小鼠模型将通过更好地理解相互作用来推动这一领域的发展 AEC和上皮内MC之间的相互作用，调节AHR和T2免疫反应。

Project Summary Airway hyperresponsiveness (AHR) is a fundamental feature of asthma and is the hallmark of the disease in the majority of patients with asthma. Our lab has been working to understand the underlying immunopathogenesis of AHR and recently discovered using three-dimensional quantitative imaging of the airway wall that in asthma there is a shift in mast cells (MC)s from the submucosa to the airway epithelium that is closely related to the severity of AHR as well as features of type-2 (T2) inflammation. This shift is critical as we identified a IL-33 dependent feed-forward loop in which MCs regulate the expression of epithelial IL-33 (IL33), indicating that MCs serve not only as effector cells but also regulate T2 inflammation through IL-33. This feed-forward loop is accentuated in airway epithelial cells (AEC)s from individuals with asthma indicating that the unique microenvironment that is established by the epithelium in asthma is critical for the propagation of AHR and T2 inflammation through this feed-forward interaction between MCs and the airway epithelium. The major goals of this research are to identify the underlying basis for MC infiltration of the airway epithelium, the molecular details of this interaction between MCs and primary AECs from individuals with asthma and the in vivo relevance of the IL-33-MC-axis using selected murine models of asthma. Given that mature MCs arise from circulating progenitors, we hypothesize that the number of MC progenitors (MCP)s in the airways is increased in asthma, and these cells function in concert with the susceptible airway epithelium to orchestrate T2 inflammation. We will directly address our hypothesis by using airway samples and primary AECs from individuals with and without asthma and/or allergic sensitization, combined with AEC- MC coculture models, and murine models of asthma in which we examine the function of the IL-33-MC-axis. In specific aim 1, we investigate the differences in the number and proliferation potential of MCPs in the airways and peripheral blood of subjects with asthma and AHR, relative to non-asthmatic control subjects with and without allergic sensitization. We further examine the expansion of MCPs in the airways following allergen challenge in individuals with asthma. In specific aim 2, we determine how the asthmatic airway epithelium interacts with MCs to regulate T2 inflammation, using an ex vivo model of primary AECs from subjects with and without asthma to examine this feed-forward mechanism. In specific aim 3, we use selective IL-33 receptor deletion in MCs in an in vivo model to understand how IL-33 acts through MCs to regulate the development of T2 inflammation and AHR. The completion of these studies using airway samples, phenotyped AECs, and sophisticated murine models will move the field forward through a better understanding of the interplay between AECs and intraepithelial MCs that serve to regulate AHR and the T2 immune response.