Function of NLRP3 in regulatory T cell-mediated control of intestinal homeostasis

NLRP3 在调节性 T 细胞介导的肠道稳态控制中的功能

• 批准号: 10748891
• 负责人: RASIKA PATKAR
• 金额: $ 4.03万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10748891
• 关键词: Ablation; Affect; Anti-Inflammatory Agents; Antigens; Autoimmune; Bacterial Infections; Biological; Bone Marrow; CASP1 gene; CD3 Antigens; Caspase; Cell physiology; Cells; Cellular Indexing of Transcriptomes and Epitopes by Sequencing; Cellular biology; Chimera organism; Chronic; Citrobacter rodentium; Complex; Cytoplasm; Data; Development; Disease; Disease model; Enteral; Exhibits; FOXP3 gene; Food; Frequencies; Future; Genes; Homeostasis; Human; IL17 gene; IL18 gene; Immune; Immune response; Immunity; Infection; Inflammasome; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Interleukin-1; Interleukin-1 beta; Intestinal Diseases; Intestines; Knockout Mice; Lymphoid; Measures; Mediating; Microbe; Modeling; Molecular; Multiprotein Complexes; Mus; Natural Immunity; Nature; Pathologic; Pathway interactions; Physiological; Play; Production; Proteins; Regulation; Regulatory T-Lymphocyte; Reporting; Role; Sorting; System; T cell differentiation; T cell response; T-Lymphocyte; T-Lymphocyte Subsets; Testing; Therapeutic; Tissues; Transcript; adaptive immunity; commensal microbes; constitutive expression; cytokine; effective therapy; gain of function; gut inflammation; immunoregulation; insight; intestinal homeostasis; loss of function; mouse model; novel; response; transcription factor; transcriptome sequencing

Project Summary The inflammasomes are cytoplasmic multi-protein complexes that can sense and be activated by microbes or tissue damage, which then leads to the activation of caspase-mediated inflammatory pathways involving the release of cytokines IL-1β and IL-18. Although the pro-inflammatory role of inflammasomes have been well established in innate immune cells, recently, several studies have uncovered a role for different inflammasome components in regulating many different T cell responses, a key part of adaptive immunity. Specifically, a subset of T cells called regulatory T cells (Tregs), which are known for their ability to suppress immune responses and inflammation, were shown to be affected by their cell intrinsic inflammasome components. Even though the critical role of Tregs in establishing tolerance to a wide range of innocuous foreign antigens from commensal microbes and food in the gut has long been well-recognized, the function of the NLRP3 inflammasome in Treg-mediated control of intestinal homeostasis remains an open question. Based on preliminary data, it was hypothesized that NLRP3/inflammasome could serve as an integral determinant in controlling Treg biology and that induction of NLRP3 in intestinal Tregs would be specifically required for their control of Th17 responses in the intestine. To test this hypothesis, the first aim will elucidate the function of NLRP3 in controlling Treg biology in the gut in heath and disease using both loss-of-function and gain-of- function approaches through employing two novel mouse models that have been recently generated in the lab: mice with Treg-specific deletion of NLPR3 and mice with Treg-specific expression of constitutively active NLRP3. Two different Th17-dependent disease models: anti-CD3 induced intestinal inflammation and Citrobacter rodentium infection model will be employed. As such, the biological impact of NLRP3 depletion or constitutive activation in Tregs on the other immune cells in the intestinal system under both physiological and pathological conditions will be elucidated. In the second aim, the molecular mechanisms underlying NLRP3- mediated control of Treg biology will be investigated. First, as IL-1b, a component of the NLRP3/inflammasome pathway was also found to be selectively induced in intestinal Tregs under inflammation, I will determine the potential role of Treg-derived IL-1b in controlling intestinal homeostasis. Next, the potential involvement of inflammasome-independent vs. –dependent mechanism underlying NLRP3-mediated Treg biology will also be examined. Finally, as the heterogeneous nature of Tregs is now well appreciated, Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) studies will be conducted to determine if there is a specific subset of Tregs that expresses NLRP3 or whether NLRP3 induction is a common feature for all intestinal Tregs under inflammation. Collectively, this study will provide mechanistic insights into the underappreciated anti-inflammatory role of NLRP3 in intestinal Tregs and will undoubtedly facilitate the development of future therapeutics for inflammatory bowel disease and other human intestinal disorders.

项目概要 炎症小体是细胞质多蛋白复合物，可以感知并被微生物或 组织损伤，然后导致 caspase 介导的炎症通路激活，涉及 释放细胞因子 IL-1β 和 IL-18。尽管炎症小体的促炎作用已被充分证实 最近，一些研究发现了先天免疫细胞中不同炎症小体的作用 调节许多不同 T 细胞反应的成分，这是适应性免疫的关键部分。具体来说，一个 T 细胞的子集，称为调节性 T 细胞 (Treg)，以其抑制免疫的能力而闻名 反应和炎症，被证明受到其细胞内在炎症小体成分的影响。甚至 尽管Tregs在建立对多种无害外来抗原的耐受性方面发挥着关键作用 肠道中的共生微生物和食物早已得到充分认识，NLRP3 的功能 Treg 介导的肠道稳态控制中的炎症小体仍然是一个悬而未决的问题。基于 初步数据表明，NLRP3/炎症小体可以作为一个完整的决定因素 控制 Treg 生物学，并且在肠道 Tregs 中诱导 NLRP3 对于它们的作用是特别需要的 控制肠道内 Th17 反应。为了检验这个假设，第一个目标是阐明 NLRP3 利用功能丧失和功能增强来控制健康和疾病状态下肠道中的 Treg 生物学 通过使用最近在实验室中生成的两种新颖的小鼠模型来实现功能方法： NLPR3 Treg 特异性缺失的小鼠和 Treg 特异性表达组成型活性的小鼠 NLRP3。两种不同的 Th17 依赖性疾病模型：抗 CD3 诱导的肠道炎症和 将采用柠檬酸杆菌感染模型。因此，NLRP3 耗尽或的生物学影响 在生理和心理条件下，Tregs 对肠道系统中其他免疫细胞的组成性激活 病理状况将得到阐明。在第二个目标中，NLRP3-的分子机制 将研究 Treg 生物学的介导控制。首先，IL-1b，NLRP3/炎症小体的一个组成部分 还发现肠道Tregs在炎症条件下被选择性诱导，我将确定 Treg 衍生的 IL-1b 在控制肠道稳态中的潜在作用。接下来，潜在的参与 NLRP3 介导的 Treg 生物学的基础，独立于炎性体与依赖于炎性体的机制也将是 检查了。最后，由于 Tregs 的异质性现在已得到充分认识，细胞索引 将进行转录组和表位测序 (CITE-seq) 研究以确定是否存在 表达 NLRP3 的特定 Tregs 子集或 NLRP3 诱导是否是所有 Treg 的共同特征 肠道 Tregs 处于炎症状态。总的来说，这项研究将为 NLRP3 在肠道 Tregs 中的抗炎作用未被充分认识，并且无疑将促进 开发炎症性肠病和其他人类肠道疾病的未来疗法。