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.

项目摘要 炎性小体是细胞质多蛋白复合物，其可以感知并被微生物或 组织损伤，然后导致涉及组织的半胱氨酸蛋白酶介导的炎症途径激活 释放细胞因子IL-1β和IL-18。虽然炎性小体的促炎作用已经被很好地证实， 建立在先天免疫细胞，最近，一些研究已经揭示了不同的炎性小体的作用， 调节许多不同T细胞反应的组分，这是适应性免疫的关键部分。特别是 调节性T细胞（Regulatory T cells，Tcells）是一种T细胞亚群，以其抑制免疫反应的能力而闻名。 反应和炎症，显示受其细胞内在炎性体组分的影响。甚至 尽管TcB在建立对广泛的无害外来抗原的耐受性方面起着关键作用， 肠道中的微生物和食物早已被公认，NLRP 3的功能 炎性小体在Treg介导的肠内稳态控制中的作用仍然是一个悬而未决的问题。基于 根据初步数据，假设NLRP 3/炎性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Treg中诱导NLRP 3对于它们的免疫应答是特别需要的。 控制肠道中的Th 17反应。为了验证这一假设，第一个目标将阐明的功能， NLRP 3在健康和疾病中使用功能丧失和功能获得两者控制肠道中的Treg生物学。 功能的方法，通过采用两种新的小鼠模型，最近已在实验室中产生： 具有Treg特异性缺失NLPR 3的小鼠和具有Treg特异性表达组成型活性NLPR 3的小鼠 NLRP 3.两种不同的Th 17依赖性疾病模型：抗CD 3诱导的肠道炎症和 将采用啮齿类柠檬酸杆菌感染模型。因此，NLRP 3耗竭或 在生理和生理条件下， 将阐明病理状况。在第二个目标中，NLRP 3- 将研究Treg生物学的介导控制。首先，作为IL-1b，NLRP 3/炎性小体的组分， 还发现在炎症条件下，在肠道THP中选择性诱导了通路，我将确定 Treg衍生的IL-1b在控制肠内稳态中的潜在作用。其次，潜在的参与 NLRP 3介导的Treg生物学背后的炎性小体独立性与依赖性机制也将被讨论 考察最后，由于现在很好地理解了TclO的异质性，因此， 将进行转录组和表位测序（CITE-seq）研究，以确定是否存在一个与基因表达相关的基因。 表达NLRP 3的TCLs的特定子集，或者NLRP 3诱导是否是所有TCLs的共同特征， 炎症下的肠道炎症。总的来说，这项研究将提供机械的见解， NLRP 3在肠道炎症中的抗炎作用未被充分认识，无疑将促进 炎症性肠病和其他人类肠道疾病的未来治疗方法的开发。