Peptides presented by DNA-specific B lymphocytes in lupus

狼疮中 DNA 特异性 B 淋巴细胞呈递的肽

• 批准号: 8930442
• 负责人: MATTHIAS R WABL
• 金额: $ 17.44万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-19 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8930442
• 关键词: Affinity; Antibodies; Antibody Affinity; Antibody Formation; Antibody Response; Antigenic Specificity; Antigens; Applications Grants; Autoantibodies; Autoantigens; Autoimmune Process; Autoimmune Responses; B-Lymphocytes; Binding; Biological Assay; CD4 Positive T Lymphocytes; Cells; Characteristics; Collection; Complex; Disease; Endocytosis; Etiology; Female; Gene Targeting; Gene Transfer Techniques; Generations; Health; Helper-Inducer T-Lymphocyte; Histones; Human; Human Characteristics; Hybridomas; Immune response; Immunoglobulin G; Kinetics; Left; Light; Lupus; MHC Class II Genes; Mediating; Methodology; Mus; Nucleosomes; Older Population; Patients; Peptides; Physiological; Population; Production; Protein Fragment; Proteins; Receptors, Antigen, B-Cell; Serum; Sorting - Cell Movement; Specificity; Spleen; Structure of germinal center of lymph node; Systemic Lupus Erythematosus; T-Lymphocyte; Testing; Transgenes; Transgenic Mice; Transgenic Organisms; anti-dsDNA antibodies; clinical Diagnosis; density; ds-DNA; immunoglobulin receptor; lupus prone mice; mouse model; protein complex; research study; response

DESCRIPTION (provided by applicant): This grant proposal aims to identify the peptides that mediate T cell help for dsDNA-specific B lymphocytes in lupus. Systemic lupus erythematosus (SLE) is a disease of unknown etiology. Female (NZB x NZW) F1 (abbreviated B/W) mice recapitulate most of the salient characteristics of human lupus patients. Among these characteristics are serum antibodies to dsDNA, which are specific for the clinical diagnosis in a majority of SLE patients, as well as in all older B/W mice. An important question, therefore, is what drives production of high-affinity anti-dsDNA antibody? In the B/W mouse, the generation of high-affinity anti-dsDNA antibodies of IgG class is absolutely T-helper- cell dependent. dsDNA by itself is not an antigen in either normal or B/W mice, and DNA is not bound and presented by MHC molecules to T helper cells. The prevailing hypothesis is that DNA-protein complexes such as nucleosomes mediate the generation of high-affinity IgG antibodies. But the identity of the physiological B cell antigen is unknown. Specifically, there are no peptides known that are presented by dsDNA-specific B cells from any lupus-prone mouse model. As a result, it is not known how T cells help induce high-affinity anti-dsDNA antibodies. To reduce the complexity of the autoimmune response, we will make use of a classic lupus mouse model that has been modified by transgenesis in a conceptually simple way. It yields a quasimonoclonal auto- immune response to (only) dsDNA, while leaving the kinetics of the response intact. Unlike the germinal center B cells in old wild-type B/W mice, with various antigenic specificities, the majority of the B cells of the old transgenic mice have identical and monoclonal dsDNA specificity with high affinity. We will sort the germinal center B cells, and elute and identify th peptides bound to their class II molecules. We will then test these peptides for their ability to stimulate T cells of the B/W mice and for their function in the production of anti-dsDNA antibody. This will indicate which antigen is internalized by the immunoglobulin receptor of B cells with high affinity to dsDNA.

描述（由申请人提供）：本拨款提案旨在鉴定介导狼疮中 dsDNA 特异性 B 淋巴细胞 T 细胞帮助的肽。系统性红斑狼疮（SLE）是一种病因不明的疾病。雌性 (NZB x NZW) F1（缩写 B/W）小鼠概括了人类狼疮患者的大部分显着特征。这些特征包括双链 DNA 的血清抗体，它对于大多数 SLE 患者以及所有老年 B/W 小鼠的临床诊断具有特异性。因此，一个重要的问题是，是什么驱动高亲和力抗 dsDNA 抗体的产生？在 B/W 小鼠中，IgG 类高亲和力抗 dsDNA 抗体的产生绝对依赖于 T 辅助细胞。在正常小鼠或 B/W 小鼠中，dsDNA 本身并不是抗原，并且 DNA 不会与 MHC 分子结合并呈递给 T 辅助细胞。普遍的假设是 DNA-蛋白质复合物（例如核小体）介导高亲和力 IgG 抗体的产生。但生理 B 细胞抗原的身份尚不清楚。具体而言，尚无已知的肽由任何狼疮易发小鼠模型的 dsDNA 特异性 B 细胞呈递。因此，尚不清楚 T 细胞如何帮助诱导高亲和力抗 dsDNA 抗体。为了降低自身免疫反应的复杂性，我们将利用经典的狼疮小鼠模型，该模型已通过转基因以概念上简单的方式进行了修改。它产生针对（仅）dsDNA 的准单克隆自身免疫反应，同时保持反应动力学完整。与老野生型B/W小鼠的生发中心B细胞不同，具有多种抗原特异性， 老转基因小鼠的大多数B细胞具有相同的单克隆dsDNA特异性，具有高亲和力。我们将对生发中心 B 细胞进行分类，并洗脱并鉴定与其 II 类分子结合的肽。然后我们将测试这些肽刺激 B/W 小鼠 T 细胞的能力以及它们在产生抗 dsDNA 抗体中的功能。这将表明哪种抗原被与 dsDNA 具有高亲和力的 B 细胞的免疫球蛋白受体内化。