Lipid Antigens for iNKT Cells in the Gut Microenvironment

肠道微环境中 iNKT 细胞的脂质抗原

• 批准号: 10555286
• 负责人: Patrick Joseph Brennan
• 金额: $ 40.33万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-06 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10555286
• 关键词: Address; Affect; Allergic Disease; Anaerobic Bacteria; Animal Model; Antigens; Archaea; Bacteria; Bacteroides fragilis; Binding; Biochemical; Cell Count; Cells; Chronic; Collaborations; Colon Carcinoma; Complex; Cytotoxic T-Lymphocytes; Data; Diet; Digestive System Disorders; Disease; Dose; Enteral; Environment; Exposure to; Food Hypersensitivity; Fractionation; Future; Gastrointestinal Diseases; Genomic approach; Germ-Free; Health; Histocompatibility; Homeostasis; Host Defense; Human; Immune; Immune response; Immune system; Immunity; Immunologics; Infant; Inflammatory Bowel Diseases; Intestines; Knowledge; Life; Link; Lipids; Lymphocyte; Lymphocyte Subset; Malignant Neoplasms; Mass Spectrum Analysis; Metabolic Diseases; Methanobrevibacter; Methods; Microbe; Modeling; Molecular; Mucous Membrane; Mus; Nature; Outcome Study; Pathway interactions; Phenotype; Play; Population; Property; Recombinants; Reporting; Role; Series; Shapes; Source; Structure; T-Cell Activation; T-Cell Receptor; T-Lymphocyte; Testing; Therapeutic; alpha-galactosylceramide; anomer; effector T cell; enteric infection; experimental study; feeding; gut microbes; gut microbiota; immunoregulation; member; mesenteric lymph node; microbial; microbial products; microbiota; microorganism; mouse model; mutant; novel; receptor; single-cell RNA sequencing; stereochemistry; sugar; symbiont; transcriptomics

Project Summary The gut microbiota is recognized as a central factor influencing immune responses. This proposal addresses two important questions in understanding how microbes regulate human health: 1) What are the microbe- derived molecules that influence immunity? 2) How does chronic exposure to microbial products alters the phenotype of immune cells in their local environment? Discovering and characterizing the molecules involved in the crosstalk between symbiont microbes and the immune system is a fundamental step towards modulating both the beneficial and harmful potential of the human-microbe relationship. The first major aspect of this project (Aims 1 and 2) uses a series of biochemical approaches to define specific bioactive microbial lipids from human-derived gut microbes that activate invariant natural killer T (iNKT) cells, a specialized lymphocyte subset that recognizes specific lipids as antigens and orchestrates immune responses in multiple contexts. Although animal models have uncovered a role for iNKT cells in immunity, the lipid antigens that they recognize remain unknown in most situations. Here, we study two human symbiont microbes that produce iNKT cell-activating lipids, an uncommon feature among gut anaerobes. To identify the specific molecular lipid species that activate iNKT cells, we will use a newly-developed method, the “T cell receptor trap,” to capture antigenic lipids. Once purified, these lipids will be characterized by mass spectrometry, including new methods that distinguish sugar stereochemistry, which is of central importance to the activity of lipids that activate iNKT cells. The second major aspect of this project (Aim 3) builds on preliminary transcriptomic data to investigate how chronic exposure to lipid antigens affects the phenotype of iNKT cells in the gut in a mouse model. Since iNKT cells orchestrate immune responses in many situations, and can be either beneficial and harmful, changes to their phenotype in the gut is likely to alter the course of enteral infection, inflammatory bowel disease, colon cancer, or food allergy. To understand how lipids in the gut regulate iNKT cell populations, we will use two reductionist models, feeding mice with experimental diets containing different levels of iNKT cell lipid antigens, or colonization of germ-free mice with lipid antigen-producing microbes. In these models, we will perform high- depth phenotyping of the gut iNKT cell populations. Together, these studies will define lipid antigens from two important members of the human gut microbiota and shed light on the mechanisms by which gut lipid antigens shape iNKT cell populations.

项目摘要 肠道微生物群被认为是影响免疫反应的核心因素。该提案涉及 了解微生物如何调节人类健康的两个重要问题：1）微生物是什么？ 影响免疫力的衍生分子2)长期暴露于微生物产品如何改变 免疫细胞在其局部环境中的表型？发现和表征所涉及的分子 在共生微生物和免疫系统之间的相互作用中， 人类与微生物关系的有益和有害潜力。 该项目的第一个主要方面（目标1和2）使用一系列生物化学方法来定义特定的 来自人源性肠道微生物的生物活性微生物脂质，其激活不变的自然杀伤T（iNKT）细胞， 一种特殊的淋巴细胞亚群，识别特定的脂质作为抗原，并协调免疫反应 in multiple多种context上下文.尽管动物模型已经揭示了iNKT细胞在免疫中的作用，但脂质 它们识别的抗原在大多数情况下仍然是未知的。在这里，我们研究两个人类共生体 微生物产生iNKT细胞活化脂质，这是肠道厌氧菌中的一种罕见特征。识别 特定的分子脂质种类，激活iNKT细胞，我们将使用一种新开发的方法，“T细胞 受体陷阱”来捕获抗原脂质。一旦纯化，这些脂质将通过质量 光谱法，包括区分糖立体化学的新方法，这对 激活iNKT细胞的脂质的活性。 该项目的第二个主要方面（目标3）建立在初步转录组学数据的基础上， 在小鼠模型中，长期暴露于脂质抗原影响肠道中iNKT细胞的表型。自从iNKT 细胞在许多情况下协调免疫反应，并且可以是有益的和有害的， 它们在肠道中的表型很可能改变肠道感染、炎症性肠病、结肠炎、 癌症或食物过敏为了了解肠道中的脂质如何调节iNKT细胞群，我们将使用两个 还原论者模型，用含有不同水平iNKT细胞脂质抗原的实验饮食喂养小鼠， 或用脂质抗原产生微生物定殖无菌小鼠。在这些模型中，我们将执行高- 肠道iNKT细胞群体的深度表型分析。 总之，这些研究将从人类肠道微生物群的两个重要成员中定义脂质抗原， 阐明了肠道脂质抗原形成iNKT细胞群的机制。