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

项目摘要 白细胞介素-2是一种有效的T细胞生长因子，在免疫和自身耐受中起关键作用。全基因 在人类中的关联研究（GWAS）已经表明，在IL 2和IL 2 RA基因座的遗传变异影响 对多种免疫介导疾病的易感性，包括过敏性哮喘、系统性红斑狼疮， 和炎症性肠病（IBD），将其确定为控制免疫活性的关键分子轴。 然而，这些多态性的疾病风险的机制基础知之甚少。我们有新 有证据表明，IL 2和IL 2 RA的顺式调节结构从基因延伸得比 以前认识到，涵盖区域窝藏已知的疾病相关的变异，我们 假设这些元件内多态性控制IL-2和IL-2 RA表达的水平和时间 来控制耐受性和炎症的平衡在这个应用中，我们提出了一个全面的屏幕， 使用最先进的表观基因组学方法， ATAC-seq和Capture-C-seq等方法。我们将确定这些元素如何促进IL 2， 使用强大的基于CRISPR/CAS9的基因组编辑方法进行IL 2 RA基因表达。为了研究 疾病相关的遗传变异在这些调控元件对免疫功能在体内系统中，我们 将分析来自贝纳罗亚研究所的基因特征受试者的反应 生物储存库，并创建其中已将正向鼠I12和I12 ra增强子序列 用人类风险等位基因替换，评估过敏性哮喘、SLE和IBD模型中的疾病易感性。 我们的研究将提供IL 2和IL 2 RA转录结构的全面图谱， IL 2和IL 2 RA与自身免疫性疾病的遗传关联的分子基础，并可能指导 设计治疗器官移植排斥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.