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)：抗原提呈细胞是免疫反应中的关键角色。它们参与启动NAVE和效应细胞，对协调对感染的反应以及对自身抗原(自身免疫)的反应至关重要。在抗原提呈细胞中，B细胞是唯一能够提呈少量抗原的细胞，它们通过表面免疫球蛋白(Ig)捕获和摄取这些抗原。根据我们的初步发现，我们推测，人类白细胞抗原-DM通过使免疫球蛋白接近MHC II，促进免疫球蛋白从免疫球蛋白中释放，在增强B细胞表面通过免疫球蛋白摄取的抗原方面起关键作用。在这里，我们建议评估DM/Ig相互作用在细胞中的功能结果。我们将设计一种B细胞株来表达GAD65特异性免疫球蛋白，以及一种不与Ig相互作用但确实与MHC II相互作用的突变型DM。我们将在一系列B细胞数量和抗原剂量范围内比较突变型DM和野生型DM在T细胞增殖试验中增强GAD65呈递的能力。我们还建议通过邻近连接分析和荧光显微镜来定位细胞中的HLA-DM/Ig相互作用的位置。虽然我们在这里关注的是B细胞中作为抗原受体的表面免疫球蛋白，但我们的结果将对其他类型的抗原提呈细胞的功能产生影响，例如巨噬细胞和树突状细胞，它们通过表面Fc受体(FCR)吸收免疫复合物。这些抗原/抗体复合体也以内体途径为靶点，在那里它们遇到了人类白细胞抗原-DM。 公共卫生相关性：在健康方面，免疫系统对外来抗原做出反应，并对感染做出反应。在自身免疫性疾病中，免疫系统对自身(自身)抗原做出反应。抗原提呈细胞通过将自身和外源抗原递呈给免疫系统的应答细胞，在有效的免疫反应的发展中发挥关键的启动作用。这个项目调查了新发现的参与抗原处理和呈递的分子之间的相互作用，这一过程是形成对外来和自身抗原的免疫反应的关键，从而导致传染病和自身免疫性疾病。采用的实验系统使用了与人类1型糖尿病相关的蛋白质。