Mechanisms of autoimmune disease risk in IL2/IL2RA-dependent immune tolerance

项目摘要 白介素2是一种强大的T细胞生长因子，在免疫和自我耐受中都起着至关重要的作用。全基因组 人类的关联研究表明，IL2和IL2RA基因座的遗传变异会影响 易患多种免疫介导性疾病，包括过敏性哮喘、系统性红斑狼疮、 和炎症性肠病(IBD)，认为这是控制免疫活动的关键分子轴。 然而，这些基因多态致病风险的机制基础还知之甚少。我们有新的 有证据表明，IL2和IL2RA的顺式调控结构比基因延伸得更远 以前认识到的，包括拥有已知疾病相关变异的地区，我们 假设这些元件中的多态控制IL-2和IL-2RA的表达水平和时间 来控制耐受性与炎症之间的平衡。在本应用程序中，我们建议对以下内容进行全面筛选 利用最先进的表观基因组与IL2和IL2RA基因相互作用的潜在顺式调控元件 像ATAC-seq和Capture-C-seq这样的方法。我们将确定这些元素如何对IL2和IL2做出贡献 使用强大的、基于CRISPR/Cas9的基因组编辑方法来表达IL2RA基因。研究其影响 在体内系统中，这些调节元件上与疾病相关的遗传变异对免疫功能的影响，我们 将分析由贝纳罗亚研究所策划的具有基因特征的受试者的反应 生物库，并创建小鼠，在其中同源小鼠IL2和IL2ra增强子序列已经被 替换为人类风险等位基因，评估过敏性哮喘、系统性红斑狼疮和IBD模型的疾病易感性。 我们的研究将提供IL2和IL2RA转录结构的全面图谱，洞察 IL-2和IL-2RA与自身免疫性疾病遗传关联的分子基础 设计治疗器官移植排斥反应和炎症性疾病的新方法。

Project Summary Interleukin-2 is a potent T cell growth factor with crucial roles in both immunity and self-tolerance. Genome-wide association studies (GWAS) in humans have shown that genetic variation at the IL2 and IL2RA loci influence susceptibility to multiple immune-mediated diseases including allergic asthma, systemic lupus erythematosus, and inflammatory bowel disease (IBD), identifying this as a key molecular axis that controls immune activity. However, mechanistic basis of disease risk for these polymorphisms is poorly understood. We have new evidence that the cis-regulatory architectures of IL2 and IL2RA extend much further from the gene than previously appreciated, encompassing regions harboring known disease-associated variants, and we hypothesize that polymorphisms within these elements control the level and timing of IL-2 and IL-2RA expression to control the balance of tolerance vs. inflammation. In this application, we propose a comprehensive screen for potential cis-regulatory elements that interact with the IL2 and IL2RA genes using state-of-the-art epigenomic approaches like ATAC-seq and Capture-C-seq. We will establish how these elements contribute to IL2 and IL2RA gene expression using powerful, CRISPR/CAS9-based genome editing approaches. To study the impact of disease-associated genetic variation at these regulatory elements on immune function in in vivo systems, we will analyze the responses of genetically characterized subjects curated from the Benaroya Research Institute biorepository, and create mice in which orthologous murine Il2 and Il2ra enhancer sequences have been replaced with human risk alleles, assessing the disease susceptibility in models of allergic asthma, SLE and IBD. Our studies will provide comprehensive maps of the transcriptional architecture of IL2 and IL2RA, insights into the molecular basis for the genetic association of IL2 and IL2RA with autoimmune disease, and may guide the design of new approaches for the treatment of organ transplant rejection and inflammatory disease.