Endogenous glycosphingolipid antigens for NKT cells

NKT 细胞的内源性鞘糖脂抗原

• 批准号: 7736664
• 负责人: Dapeng Zhou
• 金额: $ 38.5万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7736664
• 关键词: Address; Adoptive Transfer; Agonist; Anabolism; Antigen-Antibody Complex; Antigen-Presenting Cells; Antigens; Area; Asthma; Autoimmune Diseases; Autoimmunity; Bacterial Proteins; Biochemical; Biological Assay; Biology; CD1d antigen; Cell Line; Cells; Cellular Membrane; Ceramide glucosyltransferase; Characteristics; Clinical; Coenzymes; Communicable Diseases; Complex; Defect; Deficiency Diseases; Development; Disease; Enzymes; Event; Evolution; Fractionation; Generations; Genes; Genetic; Genomics; Glycolipids; Glycoside Hydrolases; Glycosphingolipids; Goals; Host Defense; Human; Human Genome; Human Genome Project; Hybrid Cells; Hybrids; Hypersensitivity; Immune; Immune System Diseases; Immune response; Immune system; Immunity; Immunologic Receptors; Immunomodulators; Infection; Information Storage; Ions; Jaw; Knockout Mice; Knowledge; Leukocyte Adhesion Deficiency; Ligands; Link; Lipid Synthesis Pathway; Lipids; Lymphocyte; MHC antigen; Malignant Neoplasms; Mass Fragmentography; Mass Spectrum Analysis; Memory; Metabolism; Molecular; Molecular Chaperones; Molecular Cloning; Mouse Strains; Mus; Natural Immunity; Natural Killer Cells; Outcome; Pathology; Pathway interactions; Pattern; Pharmaceutical Preparations; Physiological; Play; Proteins; Proteomics; RNA Interference; Receptor Signaling; Regulation; Research; Research Personnel; Research Training; Role; Series; Side; Source; Sphingolipid Activator Proteins; Staging; Stimulus; Structure; Surveys; System; T-Cell Receptor; T-Lymphocyte; T-Lymphocyte Subsets; T-Lymphocyte and Natural Killer Cell; Technology; Testing; Thymus Gland; Tissues; Toll-like receptors; Tumor Antigens; UDP-galactose beta-D-galactosyl-1,4-glycosylceramide alpha-1,3-galactosyltransferase; Vertebrates; base; cell killing; cell type; chemical synthesis; embryonic antigen; experience; fight against; insight; isoglobotriaosylceramide; killer T cell; lipid metabolism; macrophage; mast cell; microbial; neutrophil; new technology; novel strategies; novel therapeutic intervention; novel therapeutics; pathogen; prevent; progenitor; public health relevance; receptor; success; vaccine development; viral DNA; viral RNA

DESCRIPTION (provided by applicant): Natural Killer T cells (NKT) are a hybrid cell type of NK cells and T cells, but are activated only by antigenic stimulation. NKT cells bridge innate and adaptive immunity through recognition of lipid ligands from both microbial and self origins. Endogenous NKT ligands, which are metabolism products of self lipids, are involved in immuno-pathology of infectious diseases, auto-immune diseases and cancer. However, molecular identification of these endogenous ligands has been difficult due to technical barriers. Recently, we found that NB-DGJ, a drug which inhibits glucosylceramide synthase, completely abolishes the development of NKT cells. More importantly, we identified isoglobotrihexosylceramide, one of the target glycosphingolipids being inhibited by NB-DGJ, as the first known natural ligand for NKT cells. However, iGb3 synthase knockout mice showed no defect in NKT cell development and function, indicating that other GSL and/or non-GSL ligands exist. Continued development of glycolipidomics assays, assisted by ion trap mass spectrometry technology, enhances our ability to further understand these mechanisms and identify new ligands. In this project, we will test the hypothesis that at least one endogenous ligand of NKT cells, other than iGb3, exists and is responsible for the development and activation of NKT cells. Identifying one or more endogenous ligands may permit new approaches to regulating the function of NKT cells in disease settings such as cancer and autoimmune diseases. The specific aims of this project are: 1) Determine the identities of stimulatory GSL and/or non-GSL antigens by biochemical fractionation and analysis; 2) Utilize the genetic pathways to identify potential endogenous NKT ligands. The molecular identification of natural ligands for NKT cells is not only an urgent, but also a challenging task in the field of innate immunity. Although the search for these ligands has lasted more than a decade, they remain elusive. We therefore have chosen a combined approach of biochemical fractionation/characterization and genetic knockdown of key enzymes to help bring this search to fruition. The completion of human genome project and the advancement of mass spectrometry technology provide the framework to move the field of lipid antigens forward and potentially permit the identification of new therapeutic approaches to some of the most complex immune-related diseases. More important, this project will provide early insights into cellular lipidomics studies, with a specific focus on the important immunological functions of glycolipids. More than 10% of the genes in the human genome are used for lipid metabolism; thus, knowledge and experience gained in this project may have profound implications on studies of functional lipidomics, an important but little-understood area compared with proteomics and genomics. PUBLIC HEALTH RELEVANCE: NKT lymphocytes represent an essential component of innate immunity, that can jump start the adaptive immune responses and regulate the immune outcome. Understanding the identities of the natural ligands for NKT cells is a prerequisite to study the regulation of NKT cells in patho-physiological conditions. Our long-term goal is to elucidate the molecular mechanisms of the biosynthesis pathways of natural ligands for NKT cells, and to identify druggable targets of regulation. The important clinical benefit of this project is 1) novel therapeutic application of lipid-metabolism-interfering drugs in immuno-regulation of NKT cells; 2) identification of new natural NKT ligands as targets for immuno-therapy of autoimmune diseases and cancer.

描述（由申请人提供）：天然杀手T细胞（NKT）是NK细胞和T细胞的杂化细胞类型，但仅被抗原刺激激活。 NKT细胞通过识别微生物和自我起源的脂质配体来弥合先天和适应性免疫。内源性NKT配体是自脂质的代谢产物，参与了传染病，自身免疫性疾病和癌症的免疫病理学。但是，由于技术障碍，很难对这些内源配体的分子鉴定。最近，我们发现NB-DGJ是一种抑制葡萄糖酰胺合酶的药物，完全消除了NKT细胞的发展。更重要的是，我们鉴定出异形体己糖基酰胺，这是NB-DGJ抑制靶性糖果脂，是NKT细胞的第一个已知的天然配体。但是，IGB3合酶基因敲除小鼠在NKT细胞的发育和功能中没有缺陷，表明存在其他GSL和/或非GSL配体。在离子陷阱质谱技术的辅助下，继续开发糖脂素学测定法，增强了我们进一步理解这些机制并识别新配体的能力。在该项目中，我们将测试以下假设：除了IGB3以外，至少有一个NKT细胞的内源性配体存在，并且负责NKT细胞的发展和激活。识别一种或多种内源性配体可能允许新的方法来调节NKT细胞在癌症和自身免疫性疾病等疾病环境中的功能。该项目的具体目的是：1）通过生化分级和分析确定刺激GSL和/或非GSL抗原的身份； 2）利用遗传途径鉴定潜在的内源性NKT配体。 NKT细胞的天然配体的分子鉴定不仅是紧急的，而且是先天免疫领域的挑战性任务。尽管寻找这些配体持续了十多年，但它们仍然难以捉摸。因此，我们选择了生化分离/表征和关键酶的遗传敲低的组合方法，以帮助实现这种搜索。人类基因组项目的完成和质谱技术的进步为转移脂质抗原领域的框架提供了框架，并有可能允许鉴定出新的治疗方法，以识别一些最复杂的免疫相关疾病。更重要的是，该项目将提供对细胞脂肪态学研究的早期见解，并特别关注糖脂的重要免疫学功能。人类基因组中超过10％的基因用于脂质代谢。因此，该项目中获得的知识和经验可能对功能性脂质组学的研究具有深远的影响，这是与蛋白质组学和基因组学相比的重要但鲜为人知的领域。公共卫生相关性：NKT淋巴细胞代表了先天免疫的重要组成部分，可以跳到适应性免疫反应并调节免疫预后。了解NKT细胞的天然配体的身份是研究病原生理条件下NKT细胞调节的先决条件。我们的长期目标是阐明NKT细胞天然配体的生物合成途径的分子机制，并鉴定可药物调节靶标。该项目的重要临床益处是1）脂质 - 代谢互化药物在NKT细胞的免疫调节中的新型治疗应用； 2）鉴定新的天然NKT配体是自身免疫性疾病和癌症免疫治疗的靶标。