Epigenetics of severe asthma

项目摘要 在这个多PI提案中，我们将研究表观遗传机制在驱动严重哮喘中的作用。 发病机制导致小鼠致病性免疫应答的分子参与者/途径的鉴定 哮喘将有利于发现药物靶点和开发新的疫苗策略， 预防哮喘。全基因组增强子分析是一种强大的新工具，使研究人员能够 精确地跟踪基因及其同源增强子，从而捕获细胞内参与的分子事件， 发展和分化。我们已经成功地将这个工具微尺度化， 这些研究有可能揭示人类疾病的新分子机制。在这 我们将在约100例严重哮喘患者中定义哮喘相关的表观遗传标记， 这些具有临床表型以获得可区分疾病状态的特异性分子标记（即， 严重哮喘表型）。我们将利用三个纵向哮喘队列：（i）Wessex哮喘队列， 难治性哮喘队列（WATCH），一个正在进行的积极招募的观察性临床队列（约25名新 例/月），目前包括约250例重度哮喘受试者，这些受试者由 治疗医生（PI Ramesh/Hasan，英国），（ii）NIH资助的IOW，英国队列>100例表型良好的轻度 （iii）拉霍亚研究所（LJI）队列的40名轻度至中度哮喘受试者， 在两年内每6个月提供一次血液样本。 在目标1中，我们将描述与严重哮喘发病机制相关的免疫细胞类型中的增强子景观 (na从纵向收集的血液中分离的TH 2记忆T细胞亚群和经典单核细胞 来自200名哮喘严重程度不同的受试者的样本。我们将进行比较生物信息学分析 以确定与严重哮喘相关的免疫细胞增强剂。我们还将进行转录谱分析， 血液和气道免疫细胞，以精确定义受增强子影响的基因 在严重哮喘中发现。目的2：明确重症哮喘相关增强子的靶基因 并确定与哮喘风险相关的遗传变异是否会影响其功能。然后我们将测试 这些基因在原代人T细胞中使用优化的微尺度免疫学测定。总体而言，我们 基于发现的表观遗传学研究和后续功能研究将发现新的基因和途径 参与严重哮喘和皮质类固醇不敏感性，并可能开辟治疗严重哮喘的新途径。

PROJECT SUMMARY In this multi-PI proposal we will investigate the role of epigenetic mechanisms in driving severe asthma pathogenesis. The identification of molecular players/pathways that lead to pathogenic immune responses in asthma will be beneficial for the discovery of drug targets and development of new vaccine strategies to prevent asthma. Genome-wide enhancer profiling is a powerful new tool that has allowed investigators to precisely track genes and their cognate enhancers and thus capture molecular events involved in cellular development and differentiation. We have successfully micro-scaled this tool to enable large-scale human studies that have the potential to unravel novel molecular mechanisms underlying human diseases. In this proposal, we will define asthma-related epigenetic markers in ~100 patients with severe asthma, and correlate these with clinical phenotypes to obtain specific molecular markers for distinguishable disease states (i.e. severe asthma phenotypes). We will capitalize on three longitudinal asthma cohorts: (i) the Wessex AsThma CoHort of difficult asthma (WATCH), an observational clinical cohort with on-going active recruitment (~25 new cases/month) that currently consists of ~250 subjects with severe asthma, who are actively followed up by the treating physicians (PI Ramesh/Hasan, UK), (ii) The NIH-funded IOW, UK cohort of >100 well-phenotyped mild asthmatics; (iii) the La Jolla Institute (LJI) cohort of 40 subjects with mild-to-moderate asthma, who have provided blood samples every 6 months over two years. In Aim 1, we will profile the enhancer landscape in immune cell types relevant to severe asthma pathogenesis (naïve, TH2 memory T cell subsets and classical monocytes), isolated from longitudinally collected blood samples from 200 subjects with varying asthma severity. We will perform comparative bioinformatics analysis to identify the immune cell enhancers linked to severe asthma. We will also perform transcriptional profiling of blood and airway immune cells to precisely define the genes that are affected (influenced) by the enhancers identified in severe asthma. In Aim 2, we will define the target genes of severe asthma associated enhancers and determine if genetics variants linked to asthma risk affect their function. We will then test the function of these genes in primary human T cells using optimized micro-scaled immunological assays. Overall, our discovery-based epigenetic studies and follow up functional studies will identify novel genes and pathways involved in severe asthma and corticosteroid insensitivity, and could open novel ways to treat severe asthma.