Genetic and Immunological Dissection of Eosinophilic Esophagitis

项目摘要 这项研究的长期目标是阐明嗜酸性食管炎的遗传和免疫学特征 (EoE)。EoE是一种新出现的慢性疾病，通常始于儿童时期，一直持续到成年， 与相当高的发病率相关，但目前还没有FDA批准的治疗方法。理解这一点 本课题对于阐明鸡传染性支气管炎的基本遗传和免疫学特征具有重要意义。 疾病有可能带来更好的诊断和治疗。这项提议的中心假设是 全基因组关联研究(GWAS)询问，随后是遗传和生物学验证，将揭示 涉及疾病病因学的关键过程，重点是适应性免疫和先天免疫的接口。 这一假说的基本原理是基于我们之前的研究，包括已确定疾病的最初GWAs 染色体2p23和5q22的易感性。越来越多的证据表明，这两个基因座上的致病基因 分别为CAPN14(Calain 14)和TSLP(胸腺间质淋巴生成素)。这些发现转移了人们的注意力 从原发嗜酸性粒细胞缺陷到上皮反应是EoE发病的原因。机械论 研究证实，CAPN14有助于受损的上皮屏障功能，而TSLP促进 与IL-5和IL-13过度产生相关的获得性2型T细胞免疫。CAPN14位于界面上 先天免疫和获得性免疫，因为它由食道上皮结构性表达；然而，它也是 明显由IL-13诱导，可能来自食物抗原激活的Th2细胞。除了这两个基因 基因座(2p23，5q22)，GWAs还涉及到许多其他的提示基因座，其中11个是最近发现的 初步涉及使用定制设计的Illumina SNP阵列方法，然后是初步功能 分析。尽管有这些进展，EoE发病的致病基因变异和/或基因组途径 在很大程度上仍不清楚。在这里，我们将检验相关的关键假设，即GWAS讯问之后 通过遗传和生物验证，将揭示疾病的病因学。我们将通过3个例子来验证这一中心假设 利用结合了遗传学和生物学研究的创新方法，实现免费的目标。在目标1中，我们将 将重点放在GWA主线索CAPN14上。我们将检验CAPN14是一个重要的调节因子的假设。 细胞连接和屏障的完整性，并有助于IL-13诱导的EoE相关的上皮反应。我们 将确定其结合伙伴和潜在底物以及CAPN14缺乏的后果 小鼠食道上皮细胞和CAPN14基因的过表达在目标2中，我们将检验假设 GWAS分析的其他EoE队列的荟萃分析将细化涉案人员的参与 基因座/基因和识别新的变种。在目标3中，我们将询问与疾病相关的单核苷酸 通过创新的遗传、染色质定位、转录表达相结合的多态(SNP) 以及功能生物学研究，以确定遗传变异的相关性并确定致病基因。

Project Summary This study's long-term goal is to elucidate the genetic and immunologic features of Eosinophilic Esophagitis (EoE). EoE is an emerging chronic disease that often starts in childhood and continues into adulthood and is associated with substantial morbidity, yet there are currently no FDA-approved therapies. Understanding this subject has significant implications as elucidating the fundamental genetic and immunologic features of the disease has potential to yield improved diagnostics and therapies. The central hypothesis of this proposal is that genome-wide association study (GWAS) interrogation, followed by genetic and biological validation, will uncover key processes involved in disease pathoetiology with a focus on the interface of adaptive and innate immunity. The rationale for this hypothesis is based on our prior studies, including initial GWAS that have identified disease susceptibility at chromosomes 2p23 and 5q22. Evidence is accumulating that the causal genes at these 2 loci are CAPN14 (calpain 14) and TSLP (thymic stromal lymphopoietin), respectively. These findings shift the focus from primary eosinophil defects to epithelial responses as being causal of EoE pathogenesis. Mechanistic studies have established that CAPN14 contributes to impaired epithelial barrier function and that TSLP promotes adaptive type 2 T cell immunity associated with overproduction of IL-5 and IL-13. CAPN14 sits at the interface of innate and adaptive immunity, as it is constitutively expressed by esophageal epithelium; however, it is also markedly induced by IL-13, likely derived from food antigen–activated Th2 cells. In addition to these 2 genetic loci (2p23, 5q22), GWAS have implicated numerous other suggestive loci, of which 11 have been recently preliminarily implicated using a custom-designed Illumina SNP array approach followed by preliminary functional analyses. Despite these advances, the causal gene variants and/or genomic pathways for EoE pathogenesis remain largely unclear. Herein, we will test the relevant and key hypothesis that GWAS interrogation, followed by genetic and biological validation, will uncover disease pathoetiology. We will test this central hypothesis via 3 complimentary aims using innovative approaches that combine genetic and biological studies. In Aim 1, we will focus on a primary GWAS lead, CAPN14. We will test the hypothesis that CAPN14 is an essential regulator of cellular junctions and barrier integrity and contributes to IL-13–induced, EoE-related epithelial responses. We will identify its binding partners and potential substrates and the consequences of CAPN14 deficiency in esophageal epithelial cells and CAPN14 transgenic overexpression in mice. In Aim 2, we will test the hypothesis that meta-analysis of additional EoE cohorts analyzed by GWAS will refine the involvement of implicated loci/genes and identify new variants. In Aim 3, we will interrogate disease-associated single-nucloeotide polymorphisms (SNPs) by a combination of innovative genetic, chromatin mapping, transcriptomic expression profiling, and functional biological studies to establish relevance of the genetic variants and identify causal genes.