CIS-REGULATORY CIRCUITS FOR ILC FUNCTION AND PLASTICITY

项目摘要 先天性和适应性免疫系统的细胞必须达到微妙的调节平衡， 有效地消除病原体，同时最大限度地减少邻近组织的损伤。监管缺陷 控制细胞或可溶性介质表达的机制可干扰病原体清除或 导致与自身免疫相关的未受抑制的炎症反应。最近的研究表明， 先天性免疫系统包括辅助性T（Th）细胞的功能对应物，其缺乏抗原特异性免疫应答。 受体，并以增强的动力学和活力对致病性损伤诱导的危险信号作出反应。的 Th的对应物，称为先天淋巴细胞（ILC），也参与了几种免疫缺陷病毒的发病机制。 自身免疫性疾病，包括炎症性肠病（IBD）。在发现驱动的分析研究中， 在R21的支持下，Co-PI最近定义了Th-ILC对应方的监管环境 来自发炎的人类粘膜，揭示了常规和超级增强剂的集合， 控制关键免疫介质的表达。此外，许多在特异性ILC或 Th细胞亚群与自身免疫相关疾病SNP共定位，提示调节元件可能 对于控制介导自身免疫发病机制的附近基因的表达水平是重要的。尽管 这一进展，这些潜在的重要调控元件在细胞类型，激动剂， 疾病特异性基因表达仍未经测试。本项目的目标是解决这些问题 突出的问题，重点是调节IL 22-IL 23 R-IL 1 R1-STAT 3轴，这对免疫至关重要 ILC 3-Th 17对应物的功能，并且其遗传基因座富含自身免疫相关的SNP。该公司- PI还将定义和测试ILC 3调节组的关键方面，这些调节组控制它们向ILC 1的功能转换， 炎症性肠病发病机制中所涉及的过程。为了实现这些目标，我们将利用Co-PI的互补性， 专业知识科隆纳博士的实验室发现了几个ILC亚型，并有助于我们了解它们的 在小鼠和人类中的生物学。Oltz博士的实验室研究了驱动淋巴细胞发育的顺式调节回路 和转变。提出了三个具体的目标来检验假设：（i）独特的增强子集 对于IL 22和IFNG的细胞类型特异性和激动剂特异性表达是关键的，（ii）疾病的一个子集， 相关的SNP破坏转录因子结合和增强子功能以改变IL 23 R、STAT 3或IL 1 R ILC 3和Th 17细胞在自身免疫发病过程中的表达，以及（iii）ILC 3 → ILC 1转化需要 完全激活ILC 1相关的增强子，这些增强子在ILC 3中保持平衡，相反， ILC 3特异性增强子，可能将它们转化为抑制状态。我们的项目将共同确定 ILC-Th调节体的特征主导了参与自身免疫性疾病的基因的表达模式， 炎症，提供了对细胞因子表达细胞在发病机制中的独立作用的见解，最终 开辟了新的治疗途径。

PROJECT SUMMARY A delicate regulatory balance must be achieved in cells of the innate and adaptive immune systems to effectively eliminate pathogens, while minimizing damage in neighboring tissues. Defects in regulatory mechanisms that govern expression of cellular or soluble mediators can interfere with pathogen clearance or lead to unchecked inflammatory responses associated with autoimmunity. Recent studies have revealed that the innate immune system includes functional counterparts of T helper (Th) cells, which lack antigen-specific receptors and respond with enhanced kinetics and vigor to danger signals induced by pathogenic insults. The Th counterparts, called innate lymphoid cells (ILCs), have also been implicated in the pathogenesis of several autoimmune diseases, including inflammatory bowel disease (IBD). In discovery-driven profiling studies supported by an R21, the Co-PIs have recently defined the regulatory landscapes of Th-ILC counterparts derived from inflamed human mucosae, revealing collections of conventional- and super-enhancers that may control the expression of key immune mediators. Moreover, many enhancers that were active in specific ILC or Th subsets co-localized with autoimmune-associated disease SNPs, suggesting the regulatory elements may be important for controlling expression levels of nearby genes that mediate autoimmune pathogenesis. Despite this progress, the precise role of these potentially important regulatory elements in cell type-, agonist-, and disease-specific gene expression remains untested. The goal of the current project is to address these outstanding issues, focusing on regulation of the IL22-IL23R-IL1R1-STAT3 axis, which is critical for immune function of ILC3-Th17 counterparts and whose genetic loci are rich in autoimmune-associated SNPs. The Co- PIs will also define and test key aspects of the ILC3 regulome that control their functional conversion to ILC1, a process implicated in IBD pathogenesis. To achieve these goals, we will leverage the Co-PIs' complementary expertise. Dr. Colonna's lab discovered several ILC subsets and contributed to our understanding of their biology in mice and humans. Dr. Oltz's lab studies cis-regulatory circuits that drive lymphocyte development and transformation. Three specific aims are proposed to test the hypotheses that: (i) unique sets of enhancers are critical for cell type- and agonist-specific expression of IL22 and IFNG in vivo, (ii) a subset of disease- associated SNPs disrupts transcription factor binding and enhancer function to alter IL23R, STAT3, or IL1R expression in ILC3 and Th17 cells during autoimmune pathogenesis, and (iii) ILC3ILC1 conversion requires full activation of ILC1-associated enhancers that remain poised in ILC3 and, conversely, a decommissioning of ILC3-specific enhancers, perhaps converting them to a repressed state. Together, our project will identify key features of the ILC-Th regulomes that dominate expression patterns of genes involved in autoimmune inflammation, providing insights into independent roles of cytokine expressing cells in pathogenesis, ultimately opening new therapeutic avenues.