Trained Immunity in the Airway Mucosa Differentiates Asthma from Allergy Alone

项目摘要 尽管治疗剂随处可得，但在全球3亿人中，超过一半的人患有 哮喘对疾病的控制不充分，导致病情恶化的风险增加， 给美国的医疗保健系统带来了经济负担。更有效和更有效的疗法显然是 需要并将通过增加我们对哮喘发病机制的了解来确定。 过敏是哮喘发生的危险因素，大多数哮喘病例都是过敏的。然而， 并非所有全身过敏的人在接触变应原时都会出现哮喘症状。这些 过敏性非哮喘患者可能会因过敏原而患上过敏性鼻炎，但没有 哮喘的下呼吸道症状。有趣的是，许多过敏性非哮喘患者 会随着时间的推移而出现哮喘症状，这表明导致哮喘的致病机制可能 是渐进的和可逆的。因此，确定区分过敏性哮喘表型的因素 个体可以为哮喘的发病机制提供重要的见解，并确定治疗靶点。在健康方面， 呼吸道上皮细胞(AEC)和单核巨噬细胞(MNP)有助于维持组织内环境的稳定 抵御病原体。然而，在哮喘中，AEC产生促炎信号以响应 然后通过激活MNP在肺内启动和传播2型免疫反应的过敏原。我们的 已公布的和初步的研究表明，AEC和MNP对 过敏性哮喘患者(AA)与过敏性非哮喘对照组(AC)的过敏原比较，包括差异基因 过敏性疾病中代谢途径的表达和调节以及炎症反应的增强 哮喘患者。这些研究表明，AEC和MNP可以进行表观遗传修饰和代谢 重新编程导致持久的免疫记忆和对后续事件的增强反应 曝光。这种功能性的重新编程被称为训练免疫，虽然已经在上下文中对其进行了研究 在感染性疾病中，它还没有在肺部炎症性疾病的背景下进行探索，例如 哮喘。我们的假设是过敏性哮喘患者的AEC和呼吸道MNP细胞具有训练有素的 对导致哮喘表型的过敏原的免疫反应。具体目标是：1)确定 哮喘和非哮喘过敏性受试者AEC和呼吸道MNP基因座转录可及性研究 2)比较过敏性哮喘患者和非哮喘患者的AEC和气道MNP的代谢特征。 我们将使用鼻刷和支气管镜直接采样AEC和MNP以及支气管肺泡灌洗 用于转座酶可及染色质测序的单细胞分析的AA和AC呼吸道液体 SEQ)和代谢组学来确定基因调控和代谢是否存在根本差异 这些组织之间的AEC和MNP的情况。

Project Summary Despite the widespread availability of therapeutic agents, more than half of the 300 million people worldwide with asthma have inadequate control of their disease resulting in an increased risk of exacerbations and a large economic burden to the United States health care system. More effective and curative therapies are clearly needed and will best be identified by increasing our understanding of the pathogenic mechanisms of asthma. Allergy is a risk factor for the development of asthma, and most cases of asthma are allergic in origin. However, not all individuals with systemic allergen sensitization develop asthma symptoms upon allergen exposure. These allergic non-asthmatic individuals may develop allergic rhinitis in response to an allergen but do not have the lower respiratory tract symptoms characteristic of asthma. Interestingly, many allergic non-asthmatic patients will develop asthma symptoms over time, suggesting that the pathogenic mechanisms leading to asthma may be incremental and reversible. Thus, determination of factors that differentiate the asthma phenotype in allergic individuals could provide important insights into asthma pathogenesis and identify therapeutic targets. In health, airway epithelial cells (AEC) and airway mononuclear phagocytes (MNP) help to maintain tissue homeostasis and defend against pathogens. However, in asthma, AEC generate pro-inflammatory signals in response to allergens that then initiates and propagates a type 2 immune response in the lung via activation of MNP. Our published and preliminary studies demonstrate that the AEC and MNP have profoundly different reactions to allergens in allergic asthmatics (AA) compared to allergic non-asthmatic controls (AC), including differential gene expression and regulation of metabolic pathways, and an enhanced inflammatory response in allergic asthmatics. These studies suggest that AEC and MNP can undergo epigenetic modifications and metabolic reprogramming leading to a lasting immunological memory and enhanced response towards subsequent exposures. This functional reprogramming is called trained immunity, and while it has been studied in the context of infectious diseases, it has not been explored in the context of pulmonary inflammatory diseases such as asthma. Our hypothesis is that AEC and airway MNP cells in allergic asthmatic individuals have a trained immune response to allergens which drives the asthma phenotype. The specific aims are to: 1) Determine the transcriptional accessibility of gene loci in AEC and airway MNP from allergic subjects with and without asthma.; and 2) Compare the metabolic profile of AEC and airway MNP from allergic subjects with and without asthma. We will utilize nasal brushings and bronchoscopy to directly sample AEC and MNP and bronchoalveolar lavage fluid from AA and AC airways for single cell Assay for Transposase-Accessible Chromatin sequencing (scATAC- seq) and metabolomics to determine if there are fundamental differences in the gene regulatory and metabolic landscape of AEC and MNP between these groups.