Impact of Aiolos on intestinal intraepithelial lymphocytes

项目概要/摘要 炎症性肠病（IBD）是一种常见的疾病，主要在消化道引起炎症。 道。尽管在过去的二十年里，治疗选择已经扩大，但仍有相当一部分患者 患有不良治疗反应和慢性临床过程。对现有的各种答复 治疗的部分原因是发病机制的异质性，以及可能导致 迫切需要新的治疗选择。肠上皮内淋巴细胞（IEL）是一种异质性细胞， 一组组织驻留淋巴细胞，IEL的病理激活与IBD的恶化有关。 然而，IEL在激活过程中的调节机制还不清楚。艾俄洛斯，一份抄本 由Ikzf 3编码的因子，仅在淋巴细胞中表达，并有助于B细胞活化和NK细胞 成熟Aiolos突变与包括IBD在内的各种自身免疫性疾病有关，但Aiolos的作用 在IEL或肠道内稳态中的作用在过去没有被研究过。我发现Aiolos在IEL中高度表达， 并且Aiolos缺陷IEL更活化并且表达更高水平的活化标志物（NK受体） 和细胞因子（干扰素-G和颗粒酶）。这些初步结果表明， 艾俄洛斯能强烈抑制IEL的激活由于Aiolos是调节染色质的转录因子， 重塑，我假设Aiolos结合到与IEL激活相关的基因的增强子区域， 通过改变表观遗传修饰来控制它们的表达。此外，由于Aiolos有效地调节IEL 激活，我假设Aiolos缺陷IEL调节宿主对大肠杆菌感染的反应， 肠道炎症在这个提议的项目中，我将解决这些假设与以下目标：（目的 1)鉴定Aiolos结合位点并确定Aiolos对IEL中表观遗传景观的贡献，以及（目的 2)研究Aiolos缺陷IEL在粘膜炎症期间的影响。在目标1中，我将使用状态- 最先进的表观遗传学技术来检查野生型IEL中的Aiolos结合位点，并研究Aiolos如何与IEL结合。 缺陷改变IEL中的表观遗传修饰。我计划研究表观遗传修饰 Aiolos缺陷IEL和野生型IEL之间通过比较开放染色质区域和组蛋白 修改.在目标2中，我将用Aiolos缺陷IEL的小鼠和野生型IEL的小鼠进行攻击， 鼠伤寒沙门氏菌和葡聚糖钠盐诱导的结肠炎，以描述Aiolos缺陷IEL的影响 宿主对肠道感染和炎症的反应。总之，该项目将有助于分析 IEL的顺式调节回路，并可以促进我们对IBD发病机制的理解，这可能 最终导致识别新的治疗靶点。

Project Summary/Abstract Inflammatory bowel disease (IBD) is a common disorder that causes inflammation predominantly in the digestive tract. Although treatment options have expanded in the past two decades, a significant portion of patients still suffer from poor treatment response and chronic clinical courses. Various responses to currently available therapy are in part due to the heterogeneity of pathogenesis, and novel mechanistic insight that could lead to new therapeutic options is critically needed. Intestinal intraepithelial lymphocytes (IELs) are a heterogeneous group of tissue-resident lymphocytes, and pathological activation of IELs is implicated in the exacerbation of IBD. However, the regulatory mechanisms of IELs during activation are not well understood. Aiolos, a transcription factor encoded by Ikzf3, is expressed exclusively in lymphocytes, and contributes to B cell activation and NK cell maturation. Aiolos mutations are implicated in various autoimmune diseases including IBD, but the roles of Aiolos in IELs or gut homeostasis have not been studied in the past. I discovered that Aiolos is highly expressed in IELs and that Aiolos-deficient IELs are more activated and express higher levels of activation markers (NK receptors) and cytokines (interferon-g and granzymes) compared to wild-type cells. These preliminary results indicate that Aiolos strongly suppresses IEL activation. Since Aiolos is a transcription factor modulating chromatin remodeling, I hypothesize that Aiolos binds to the enhancer regions of genes associated with IEL activation and controls their expression by altering epigenetic modifications. Additionally, since Aiolos potently regulates IEL activation, I hypothesize that Aiolos-deficient IELs modulate the host response to colitogenic infection and intestinal inflammation. In this proposed project, I will address these hypotheses with the following aims: (Aim 1) to identify Aiolos binding sites and define the contribution of Aiolos to epigenetic landscape in IELs, and (Aim 2) to investigate the impact of Aiolos-deficient IELs during mucosal inflammation. In Aim 1, I will utilize state-of- the-art epigenetic techniques to examine Aiolos binding sites in wild-type IELs and investigate how Aiolos deficiency alters epigenetic modifications in IELs. I plan to examine differences of epigenetic modifications between Aiolos-deficient IELs and wild-type IELs by comparing open chromatin regions and histone modifications. In Aim 2, I will challenge mice with Aiolos-deficient IELs and mice with wild-type IELs with Salmonella typhimurium and dextran sodium salt-induced colitis to delineate the impact of Aiolos-deficient IELs on host responses to intestinal infection and inflammation. Taken together, this project will contribute to profiling cis-regulatory circuits of IELs and could advance our understanding of the pathogenesis of IBD, which could eventually lead to the identification of new therapeutic targets.