Intestinal surveillance by intraepithelial lymphocytes

上皮内淋巴细胞的肠道监测

• 批准号: 9916735
• 负责人: Daniel S Mucida
• 金额: $ 50.85万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9916735
• 关键词: Address; Animals; Antibiotics; Bacterial Infections; Behavior; Cell physiology; Cells; Characteristics; Communicable Diseases; Communication; Data; Development; Enterocytes; Epithelial; Epithelial Cells; Epithelium; Gene Expression; Gene Targeting; Genetic Models; Germ-Free; Gnotobiotic; Immune; Infection; Inflammatory Bowel Diseases; Intestines; Intraepithelial T-Lymphocyte; Knowledge; Lead; Light; Link; Location; Lymphocyte; Lymphocyte Function; Lymphocyte Subset; Metabolic; Metabolism; Microscopy; Modeling; Modification; Molecular; Molecular Biology Techniques; Mucosal Immune System; Mucosal Immunity; Mucous Membrane; Mus; Pathogenicity; Pathway interactions; Pattern; Play; Population; Predisposition; Process; Protozoan Infections; Public Health; Reporter Genes; Resistance; Role; Scanning; Surface; Surveys; T cell regulation; T-Lymphocyte; T-bet protein; Techniques; Therapeutic Intervention; Tissues; Villus; adaptive immunity; base; cell motility; cytokine; design; enteric infection; enteric pathogen; gastrointestinal epithelium; gastrointestinal infection; gut microbiota; host-microbe interactions; in vivo; in vivo imaging; intestinal epithelium; intraepithelial; metabolic profile; microbial; multi-photon; novel; novel strategies; novel therapeutic intervention; pathogen; response; tool

Intestinal intraepithelial lymphocytes (IELs) form one of the key branches of the mucosal immune system, potentially providing a first line of immune defense against pathogens due to their location at the critical interface between the intestinal lumen and the core of the body. Although in recent years some of the mechanisms controlling the development of different IEL populations have been elucidated, the role played by IELs during gastrointestinal infection remains elusive. A few main obstacles hamper efforts to address these deficits: lack of genetic models that would allow specific control of IEL development and function, poor IEL survival ex vivo and difficult access due to their location within the epithelial compartment. This proposal addresses these main impediments using a combination of novel tools and approaches to dissect the function of these cells in vivo. First, to address IEL dynamics in vivo we will use multi-photon intra-vital as well as tissue clearing associated with light sheet microscopy. Using these techniques we have been able to track IEL dynamics in multiple villi simultaneously in naïve animals and during enteric infections. We observed that TCR+ IELs are highly mobile cells that constantly survey the intestinal epithelium, rapidly responding to pathogenic bacterial infection by changing their motility and pattern of shuffling between intestinal epithelial cells (IECs), as well as their location within the villi. These changes were linked to gene expression changes and changes in energy utilization pathways. We hypothesize that a coordinated IEC-IEL response to luminal perturbations results in modification of IEL behavior and metabolism, ultimately leading to optimal resistance to pathogen invasion. Mostly focusing on the main IEL population, TCR+ cells, the studies in this proposal will define they respond to intestinal microbes utilizing gnotobiotic mice as well as models of gastrointestinal infections. We will characterize the relative contribution of IEL cell dynamics and metabolic changes in response to enteric pathogens to their protective function. We will also study how sensing of microbes by IECs influences IEL responses against infections. Ultimately, using gene-targeting strategies and molecular biology techniques, we will investigate the role of the transcription factor T-bet in the modulation of activity of IEL subsets and the underlying molecular mechanisms. By combining gene-reporter, multiple cell-specific and temporally controlled gene targeting and in vivo imaging strategies with various model of microbial stimulation, we expect to identify specific surveillance and protective characteristics for IELs. This proposal offers completely novel approaches to dissect the function T cells that constantly scan the intestinal surface. Thus, the knowledge gained from this study will expand our understanding of adaptive immunity at the gut epithelial barrier, contributing valuable information regarding host-microbial interactions. Defining key IEL functions during intestinal defense is an important step for understanding the initial processes involved in mucosal immunity and may lead to better strategies for therapeutic intervention in gastrointestinal infections.

肠上皮内淋巴细胞（IEL）形成粘膜免疫系统的关键分支之一， 由于病原体位于关键的位置，因此可能提供针对病原体的第一道免疫防御 肠腔和身体核心之间的界面。尽管近年来一些 控制不同 IEL 群体发展的机制已被阐明， 胃肠道感染期间的 IEL 仍然难以捉摸。一些主要障碍阻碍了解决这些问题的努力 缺陷：缺乏可以具体控制 IEL 发育和功能的遗传模型，IEL 较差 由于它们位于上皮室内，因此离体存活且难以进入。这个提议 使用新颖的工具和方法组合来剖析功能来解决这些主要障碍 这些细胞在体内。首先，为了解决体内 IEL 动力学问题，我们将使用多光子活体以及组织 与光片显微镜相关的透明化。使用这些技术，我们已经能够追踪 IEL 在幼稚动物和肠道感染期间同时观察多个绒毛的动态。我们观察到 TCR+ IEL 是高度移动的细胞，它们不断地调查肠上皮，快速响应 通过改变肠上皮之间的运动和洗牌模式来控制病原菌感染 细胞（IEC），以及它们在绒毛内的位置。这些变化与基因表达变化有关 以及能源利用途径的变化。我们假设 IEC-IEL 对管腔的协调响应 扰动会导致 IEL 行为和新陈代谢的改变，最终导致最佳的抗性 病原体入侵。本提案中的研究主要集中在主要 IEL 群体、TCR+ 细胞上 利用无菌小鼠和胃肠道模型确定它们对肠道微生物的反应 感染。我们将描述 IEL 细胞动力学和代谢变化的相对贡献 对肠道病原体对其保护功能的反应。我们还将研究 IEC 如何感知微生物 影响 IEL 对感染的反应。最终，利用基因靶向策略和分子生物学 技术，我们将研究转录因子 T-bet 在 IEL 活性调节中的作用 子集和潜在的分子机制。通过结合基因报告基因、多种细胞特异性和 时间控制的基因靶向和体内成像策略与各种微生物刺激模型， 我们希望确定 IEL 的具体监测和保护特征。该提案提供 这是一种全新的方法来剖析不断扫描肠道表面的功能性 T 细胞。因此， 从这项研究中获得的知识将扩大我们对肠道上皮适应性免疫的理解 屏障，提供有关宿主-微生物相互作用的有价值的信息。定义关键 IEL 功能 肠道防御期间是了解粘膜相关初始过程的重要一步 免疫力，并可能导致胃肠道感染治疗干预的更好策略。