Immunoglobulin as a novel ligand for HLA-DM

免疫球蛋白作为 HLA-DM 的新型配体

• 批准号: 8177239
• 负责人: Elizabeth D Mellins
• 金额: $ 23.7万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-20 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8177239
• 关键词: Address; Animal Model; Antibodies; Antigen Presentation; Antigen Presentation Interaction; Antigen Presentation Pathway; Antigen Receptors; Antigen-Antibody Complex; Antigen-Presenting Cells; Antigens; Attenuated; Autoantigens; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; Binding; Biological Assay; CD4 Positive T Lymphocytes; Cell Count; Cell Line; Cells; Clinical Trials; Complex; Conjugate Vaccines; Data; Dendritic Cells; Detection; Development; Dose; Effector Cell; Engineering; Epitopes; Event; Fc Receptor; Fluorescence Microscopy; Health; Histocompatibility Antigens Class II; Human; Immune response; Immune system; Immunoglobulins; Infection; Insulin-Dependent Diabetes Mellitus; Length; Ligands; Ligation; Link; Mediating; Membrane; Microscopy; Modeling; Molecular; Pathway interactions; Peptides; Pharmaceutical Preparations; Play; Precipitation; Process; Proteins; Rheumatoid Arthritis; Role; Shapes; Site; Surface; Surface Immunoglobulins; System; T-Cell Proliferation; T-Lymphocyte; Testing; antigen binding; antigen processing; base; cell type; functional outcomes; macrophage; mutant; novel; receptor; research study; response; uptake

DESCRIPTION (provided by applicant): Antigen presenting cells are key players in the immune response. They are involved in priming naove and effector cells and are critical for orchestrating a response to infection as well as responses to self- antigens (autoimmunity). Among antigen presenting cells, B cells are uniquely capable of presenting small amounts of antigen, which they capture and take up through surface immunoglobulin (Ig). Based on our preliminary findings, we hypothesize that HLA-DM is a key player in enhancing presentation of antigen taken up through Ig on the surface of the B cell by bringing Ig in close proximity to MHC II and facilitating antigen release from Ig. Here, we propose to assess the functional outcome of the DM/Ig interaction in cells. We will engineer a B cell line to express a GAD65 specific immunoglobulin as well as a mutant DM that does not interact with Ig but does interact with MHC II. Mutant and wild type DM will be compared for their ability to enhance presentation of GAD65 in T cell proliferation assays, across a range of B cell numbers and antigen doses. We also propose to localize the site of the HLA-DM/Ig interaction in cells by using proximity ligation assays and fluorescence microscopy. Although we focus here on surface immunoglobulin as an antigen receptor in B cells, our results will have implications for the function of other antigen presenting cell types, such as macrophages and dendritic cells, that take up immune complexes via surface Fc receptors (FcR). These antigen/antibody complexes are also targeted to the endosomal pathway, where they encounter HLA-DM. PUBLIC HEALTH RELEVANCE: In health, the immune system responds to foreign antigens and mounts a response to infection. In autoimmune disease, the immune system mounts a response against the body's own (self) antigens. Antigen presenting cells mediate a critical initiating role in the development of an effective immune response by presenting self and foreign antigens to responder cells of the immune system. This project investigates a newly discovered interaction between molecules involved in antigen processing and presentation, a process that is key in shaping the immune response against foreign and self antigens with consequences for infectious as well as autoimmune diseases. The experimental system employed uses proteins of relevance to type 1 diabetes in humans.

描述（由申请人提供）：抗原呈递细胞是免疫反应中的关键参与者。它们参与启动NAOVE和效应细胞，对于策划对感染的反应以及对自抗原的反应（自身免疫性）至关重要。在抗原呈递细胞中，B细胞具有独特的能力表现出少量的抗原，它们通过表面免疫球蛋白（IG）捕获并占据。根据我们的初步发现，我们假设HLA-DM是增强通过IG在B表面上吸收的抗原表现出来的关键参与者，这是通过使IG与MHC II的接近度接近MHC II并促进IG的抗原释放。在这里，我们建议评估细胞中DM/Ig相互作用的功能结果。我们将设计B细胞系以表达GAD65特异性免疫球蛋白以及不与Ig相互作用但确实与MHC II相互作用的突变体DM。将比较突变体和野生型DM，以增强B细胞数量和抗原剂量的T细胞增殖分析中GAD65的表现能力。我们还建议通过使用接近连接测定和荧光显微镜将HLA-DM/Ig相互作用的位置定位在细胞中。尽管我们在这里集中在B细胞中的表面免疫球蛋白作为抗原受体上，但我们的结果将对其他抗原呈现的细胞类型（例如巨噬细胞和树突状细胞）的功能具有影响，这些抗原通过表面FC受体（FCR）进行免疫复合物（FCR）。这些抗原/抗体复合物也针对遇到HLA-DM的内体途径。 公共卫生相关性：在健康方面，免疫系统对外国抗原做出反应，并对感染产生了反应。在自身免疫性疾病中，免疫系统对人体自己（自身）抗原的反应产生了反应。抗原呈现细胞的抗原通过向免疫系统的响应细胞呈现自我和外国抗原来介导有效免疫反应的关键作用。该项目调查了参与抗原加工和表现的分子之间的新发现的相互作用，这一过程是塑造针对异物和自我抗原的免疫反应的关键，对感染性和自身免疫性疾病的影响。采用的实验系统使用与人类中1型糖尿病相关的蛋白质。