Determinants of induced Treg and inflammatory Th17 cell balance in response to potentially pathogenic microbiota

诱导 Treg 和炎症 Th17 细胞平衡响应潜在致病微生物群的决定因素

• 批准号: 10579197
• 负责人: Dan Littman
• 金额: $ 52.11万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-15 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10579197
• 关键词: Adopted; Affect; Antibodies; Antigen Presentation; Antigen-Presenting Cells; Autoimmune Diseases; Bacteria; Bone Marrow; CD4 Positive T Lymphocytes; Cell Communication; Cell Differentiation process; Cell Line; Cell physiology; Cells; Characteristics; Chimera organism; Chronic; Colon; Complement; Cre driver; Crohn' s disease; Dangerousness; Data; Data Set; Dendritic Cells; Docking; Endothelial Cells; Environmental Exposure; Environmental Risk Factor; Epithelial Cells; Equilibrium; Exposure to; FOXP3 gene; Genetic; Genetic Models; Genetic Predisposition to Disease; Goals; Health Benefit; Helicobacter hepaticus; Heterozygote; Histocompatibility Antigens Class II; Homeostasis; ITGAX gene; Immune system; Impairment; In Vitro; Infection; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Integrin alphaV; Interleukin-10; Intestines; Lamina Propria; Leukocytes; Location; Lymphoid Cell; MHC Class II Genes; Macrophage; Maintenance; Mediating; Microbe; Modeling; Mouse Strains; Mus; Mutant Strains Mice; Mutate; Mutation; Myeloid Cells; Pathogenicity; Pathway interactions; Phenotype; Physiological; Population; Process; Province; Regulation; Regulatory T-Lymphocyte; Reporter; Research; Risk; Role; Sorting; Specific qualifier value; Study models; System; T cell differentiation; T cell response; T-Cell Activation; T-Lymphocyte; Therapeutic; Transforming Growth Factor beta; Transgenic Organisms; Tumor Immunity; Ulcerative Colitis; Work; candidate identification; cell type; commensal bacteria; cytokine; dysbiosis; embryonic stem cell; experimental study; gut inflammation; gut microbiota; immunological synapse formation; intestinal barrier; intestinal homeostasis; intravital microscopy; lymph nodes; mesenteric lymph node; microbial; microbiota; microorganism; migration; multiphoton microscopy; new therapeutic target; pathobiont; pathogen; programs; receptor; response; single-cell RNA sequencing; spatiotemporal; transcription factor; transcriptomics; villin

Interactions of the gut microbiota with cells of the immune system govern multiple physiological functions that are manifested locally, in the regulation of intestinal barrier functions, and systemically, in autoimmune diseases and modulation of anti-tumor immunity. Although mutualistic microbial species generally provide vital health benefits to the host, some of them can conditionally cause harm under some circumstances, such as host genetic vulnerabilities or following environmental perturbation. These bacterial species, known as “pathobionts”, have been proposed to be major contributors to inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn’s disease, which are characterized by intestinal dysbiosis. A better characterization of these bacterial species and the mechanisms by which they interact with the host in healthy homeostatic conditions and during IBD-associated inflammation is critical for developing better therapeutic approaches. We study the model pathobiont Helicobacter hepaticus, which induces regulatory T cells (iTreg) in the healthy murine gut, but promotes Th17-mediated inflammation when the iTregs are compromised. H. hepaticus- specific naïve T cells are activated by antigen-presenting cells (APCs) in colon-draining mesenteric lymph nodes (mLN), and up-regulate Foxp3 and RORgt, transcription factors characteristic of intestinal iTreg. However, when IL-10 is limiting or when iTreg induction is otherwise compromised, the microbe-specific T cells express RORgt and adopt a pathogenic (p)Th17 cell program in the lamina propria. The goals of this proposal are to identify the APCs that interact with naïve H. hepaticus-specific T cells in the mLN to program either iTreg or pTh17 differentiation pathways, elucidate the molecules involved and the temporal dynamics of the APC-T cell interactions, and determine the roles of the diverse types of MHC class II-expressing cells in the intestinal lamina propria in promoting iTreg and pTh17 cell functions. In preliminary studies, we found that selective loss of either CCR7 in dendritic cells (DCs) or MHC-II in type 3 innate lymphoid cells (ILC3) resulted in abrogation of iTreg cell differentiation and in expansion, instead, of pTh17 cells in mLN and lamina propria. A similar iTreg phenotype was observed when molecules involved in TGF-b release were mutated in DCs or ILC3, suggesting that regulated local release of this iTreg-inducing cytokine requires naïve T cells to interact with both DCs and ILC3. Our first aim is to precisely characterize, through genetic and transcriptomic approaches, the cell types required for iTreg induction in the mLN, and rule out potential for misinterpretation due to expression of Cre in rare uncharacterized APCs or to indirect effects of the cell type-restricted mutations; and determine the spatiotemporal interactions of the cells, using multiphoton microscopy. The second aim is to identify the CCR7- independent APC(s) required for pTh17 cell induction in settings of compromised iTreg induction. The third aim is to leverage the H. hepaticus-specific system to investigate potential non-T cell priming functions of diverse MHC-II-expressing cell types in the intestinal lamina propria, including epithelial and endothelial cells.

肠道菌群与免疫系统细胞的相互作用控制多种生理功能 在本地表现出在肠屏障功能的调节中，并且在自身免疫性中表现出来 抗肿瘤免疫学的疾病和调节。 对主机的健康益处，其中一些可能在某些情况下有条件地造成伤害，例如 宿主遗传脆弱性或以下环境扰动。这些细菌，称为 已提议“病原体”是炎症性肠病（IBD）的主要因素 溃疡性结肠炎和克罗恩病，其特征是肠道营养不良。更好的表征 这些细菌物种及其在健康稳态中与宿主相互作用的机制 条件和在IBD相关的感染期间对于开发更好的治疗方法至关重要。我们 研究模型病原体肝杆菌肝杆菌，该模型在健康中诱导调节性T细胞（ITREG） 鼠类肠道，但在ITRERS受到损害时会促进Th17介导的炎症。 H. Hepaticus- 特定的幼稚T细胞通过抗原呈递细胞（APC）激活结肠排水肠系膜淋巴 节点（MLN）和上调FOXP3和RORGT，肠道ITREG的转录因子的特征。 但是，当IL-10限制或其他损害ITREG诱导时，微生物特异性T细胞 表达RORGT并在固有层中采用致病性（P）Th17细胞程序。该提议的目标 是要识别与MLN中hepatius特异性T细胞相互作用的APC以编程ITREG 或PTH17分化途径，阐明涉及的分子和APC-T的临时动力学 细胞相互作用，并确定肠中MHC II类表达细胞的潜水员类型的作用 在促进ITREG和PTH17细胞功能方面的层层。在初步研究中，我们发现选择性损失 在树突状细胞中的CCR7（DC）或3型先天淋巴样细胞中的MHC-II（ILC3）导致废除 ITREG细胞分化和扩张中的PTH17细胞在MLN和lamina propria中。类似的ITREG 当在DCS或ILC3中突变参与TGF-B释放的分子时观察到表型，这表明 调节该ITREG诱导细胞因子的局部释放需要幼稚的T细胞与DC相互作用 ILC3。我们的第一个目的是通过遗传和转录组方法精确表征细胞类型 MLN中ITREG诱导所需的要求，并排除由于CRE在 罕见的未表征的APC或细胞类型限制突变的间接作用；并确定 使用多光子显微镜检查细胞的时空相互作用。第二个目的是确定CCR7- PTH17细胞诱导所需的独立APC在受损ITREG诱导的设置中。第三个目标 是利用肝素特异性系统来研究潜水员的潜在非T细胞启动功能 肠道层中的MHC-II表达细胞类型，包括上皮和内皮细胞。