Dissecting the intestinal niche for regulatory T cells

剖析调节性 T 细胞的肠道生态位

• 批准号: 10480404
• 负责人: TERRI M. LAUFER
• 金额: --
• 依托单位: PHILADELPHIA VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10480404
• 关键词: 3-Dimensional; Affect; Anatomy; Antibiotics; Autoimmune; B-Lymphocytes; Birth; Blocking Antibodies; CD4 Positive T Lymphocytes; Cell Communication; Cell Count; Cell physiology; Cells; Chemicals; Clinical; Colonoscopy; Crohn' s disease; Cytoprotection; Data; Defect; Development; Disease; Disease Outcome; Environment; Expression Profiling; FOXP3 gene; Flare; Flow Cytometry; Funding; Genomic Segment; Health; Homeostasis; Human; Image; Imaging Techniques; Immune; Immune system; Immunofluorescence Immunologic; Immunologics; Immunotherapy; Individual; Infant; Infection; Inflammation; Inflammatory Bowel Diseases; Intestines; Lamina Propria; Lead; Location; Lymphoid Follicle; Maintenance; Mature B-Lymphocyte; Mediating; Methodology; Methods; Modeling; Molecular; Mucosal Immune Responses; Mucous Membrane; Mus; Organ Donor; Organism; Pathway interactions; Patients; Peripheral; Phenotype; Physiological; Population; Positioning Attribute; Predisposition; Prevalence; Process; Recovery; Regulatory Pathway; Regulatory T-Lymphocyte; Research Design; Signal Transduction; Small Intestines; Specimen; Subcellular Anatomy; Therapeutic; Thymus Gland; Tissues; Ulcerative Colitis; Veterans; Villus; Wild Type Mouse; autoinflammatory; enteritis; experimental study; genetic manipulation; gut inflammation; gut microbiota; human tissue; improved; innovation; intestinal epithelium; intestinal homeostasis; lymphoid structures; lymphotoxin beta; men; microorganism; mouse model; mucosal site; organizational structure; pharmacologic; prevent; response; segregation; transcription factor

1. Objective: Inflammatory bowel diseases (IBD), including Crohns Disease and Ulcerative Colitis, arise in genetically-susceptible hosts when intestinal epithelial defects and heightened responsiveness towards commensal organisms lead to excessive activation of CD4+ T cells and tissue damage. IBD is also associated with loss of regulatory pathways including defects in regulatory T cells (Tregs). Tregs, a subset of Foxp3- positive CD4+ T cells, are central to intestinal tolerance; they prevent the development of IBD disease and suppress inflammation during infection. In this application, we seek to understand the mechanisms that maintain intestinal Tregs during health and inflammation. Regulatory T cells include two developmentally distinct subsets: thymus-derived (tTreg or natural (nTreg) and peripherally-derived (pTreg) that differentiate from conventional naïve CD4+ T cells. Human and mouse intestine contain cells of both lineages and both are necessary to maintain tolerance. Foxp3-deficient IPEX patients, lacking natural Tregs, develop autoimmune enteritis as infants. Separately, loss of the genomic region that controls peripheral differentiation of pTregs also leads to intestinal inflammation. Thus, both murine and human studies demonstrate a requirement for both populations for the maintenance of intestinal tolerance. There are no data defining distinct mechanistic or anatomic requirements for the two populations. Treg localization and phenotypes were examined in mice lacking peripheral TCR-MHCII interactions and peripheral conversion of Tregs (pTregs). Thymically-generated nTregs entered the small intestine lamina propria (siLP) to fill the compartment in the absence of MHCII. Imaging of intact tissue shows that Tregs in the siLP have two distinct anatomic locations: individually localized within the siLP villus or clustered within organized structures resembling isolated lymphoid follicles (ILFs). Our data suggest that a subset of Tregs preferentially localize to ILFs; this association is altered during infection. Additionally, nTregs and pTregs occupy an overlapping niche despite having different requirements for costimulatory signals. Thus, we present the hypotheses that 1. thymic-derived and peripheral Tregs occupy distinct physiologic niches in the small intestine, and 2 ILFs provide a niche for Tregs that is malleable during inflammation. 2. Research Design: In our first Aim, we will utilize murine models and healthy human tissue to determine if ILFs are required for the maintenance of siLP Tregs, define the costimulatory signals present in the ILF, and then ask if the ILF specifically attracts and maintains thymic Tregs in contrast to pTregs. Multiple studies in mice and men find that both infectious and autoimmune intestinal inflammation is associated with expansion of ILFs and altered Treg dynamics. Yet, there are no data on how these changes affect the positioning and maintenance of Tregs and recovery from inflammation. In our second Aim, we will examine murine models of inflammation and specimens from IBD patients to define how inflammation alters ILF-Treg interactions. 3. Methodology: Mice with altered MHCII expression will be compared with wildtype mice. Small intestine from healthy Our data suggest thymic Tregs preferentially localize to ILFs.and IBD patients will also be examined. The immune system will be altered utilizing blocking antibodies, antibiotics, genetic manipulations, and infections. Methods will include molecular and cellular analyses of cell populations and responses by flow cytometry, expression profiling, and imaging techniques. 4. Findings: This proposal not been funded. 5. Clinical Relationships: The prevalence of inflammatory bowel disease has been increasing amongst veterans. The current study is directed towards defining pathways that can be manipulated therapeutically to increase the number of localized regulatory T cells to improve IBD outcomes.

1。目的：炎症性肠病（IBD），包括克罗恩斯疾病和溃疡性结肠炎 当肠上皮缺陷并提高了对 共生生物会导致CD4+ T细胞的过量激活和组织损伤。 IBD也有关联 随着调节途径的损失，包括调节T细胞中的缺陷（TREG）。 Tregs，Foxp3的子集 - 阳性CD4+ T细胞是肠道耐受性的核心。它们阻止了IBD疾病的发展和 抑制感染过程中的注射。在此应用中，我们试图了解 在健康和感染期间保持肠道。调节性T细胞在开发方面包括两个 不同的子集：胸腺衍生（Ttreg或Natural（Ntreg）和外围衍生（Ptreg） 来自常规的CD4+ T细胞。人类和小鼠肠中都包含两个谱系的细胞，并且均为 维持宽容所必需的。 FOXP3缺乏IPEX患者缺乏天然Treg，会发展自身免疫性 肠炎作为婴儿。另外，控制PTREG的外围分化的基因组区域的丧失 导致肠炎。这是鼠类和人类研究都证明了两者的要求 维持肠道耐受性的种群。没有定义不同机械或 两个人群的解剖要求。 在缺乏周围TCR-MHCII相互作用的小鼠中检查了Treg定位和表型 Tregs（Ptregs）的外围转换。胸腺生成的Ntregs进入了小肠薄片 在没有MHCII的情况下，PROPRIA（SILP）填充了隔室。完整组织的成像显示 SILP有两个不同的解剖位置：单独定位在SILP绒布内或聚集在内部 有组织的结构类似于分离的淋巴卵泡（ILFS）。我们的数据表明Tregs的子集 优先定位于ILF；这种关联在感染过程中发生了改变。此外，ntregs和ptregs 尽管对共刺激信号有不同的要求，但仍占据重叠的利基市场。那，我们介绍 假设1。胸腺衍生和周围的Treg占据了不同的生理壁ni 小肠和2个ILF为炎症期间可延展的treg提供了一个利基。 2。研究设计：在我们的第一个目标中，我们将利用鼠模型和健康的人体组织来确定是否是否 ILF是维护SILP Treg所必需的，定义了ILF中存在的共刺激信号，并且 然后询问ILF是否特异性吸引并保持胸腺treg treg与Ptregs相比。多次研究 小鼠和男性发现感染性和自身免疫性肠炎都与扩张有关 ILF和改变Treg动力学。但是，没有关于这些变化如何影响定位的数据 维持Tregs和从炎症中恢复。在我们的第二个目标中，我们将研究 IBD患者的炎症和标本定义感染如何改变ILF-Treg相互作用。 3。方法论：将MHCII表达改变的小鼠与野生型小鼠进行比较。小肠 从健康中，我们的数据表明胸腺treg优先定位于ILF。 检查。免疫系统将使用阻断抗体，抗生素，遗传操纵， 和感染。方法将包括对细胞群体的分子和细胞分析，以及流动的反应 细胞仪，表达分析和成像技术。 4。调查结果：该提案未得到资助。 5。临床关系：炎症性肠病的患病率一直在增加 退伍军人。当前的研究针对定义可以治疗的途径 增加局部调节T细胞的数量以改善IBD结果。