The role of complement citrullination in RA pathogenesis

补体瓜氨酸化在 RA 发病机制中的作用

• 批准号: 9315724
• 负责人: Felipe Andrade
• 金额: $ 36.46万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-16 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9315724
• 关键词: Address; Affect; Amplifiers; Antibodies; Antigens; Arthritis; Autoantibodies; Autoantigens; Autoimmune Process; B-Cell Activation; B-Lymphocytes; Biochemical; Biological Assay; Cells; Clinical; Complement; Complement Activation; Complement Factor H; Complement Membrane Attack Complex; Data; Deposition; Disease; Disease Outcome; Enzymes; Event; Feeds; Immune; Immune Targeting; Immune response; Immune system; Impairment; Infiltration; Inflammation; Inflammatory; Joints; Lytic; Mass Spectrum Analysis; Measures; Mediating; Modification; Outcome; Outcome Study; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Post-Translational Protein Processing; Prevalence; Process; Production; Protein-arginine deiminase; Proteins; Publishing; Regulation; Rheumatism; Rheumatoid Arthritis; Role; Subgroup; Synovial Fluid; Synovial Membrane; Testing; Therapeutic Intervention; Tissues; To autoantigen; Vitronectin; Work; articular cartilage; bone erosion; cell injury; chronic autoimmune disease; citrullinated protein; clinically significant; cohort; complement C3d,g; complement system; feeding; genetic regulatory protein; in vitro Assay; in vivo; joint injury; multiple reaction monitoring; neutrophil; novel; response; targeted treatment

PROJECT SUMMARY/ABSTRACT Understanding the mechanisms which drive immune responses to autoantigens is of high priority. In rheumatoid arthritis (RA), protein citrullination is a major target of the immune system. Significant data implicates the anti-citrullinated protein immune response in RA pathogenesis, with recent evidence suggesting that mechanisms which enhance citrullination are associated with the worst disease outcome. While different mechanisms likely promote citrullination in RA, our published and preliminary data suggest that citrullination and the complement system are interacting pathways that amplify each other to enhance autoantigen production and immune-mediated damage in a sizable subset of RA patients. Thus, we have found that cellular membranolysis mediated by complement is a potent inducer of protein citrullination in the RA joint, and that this process is associated with citrullination of critical regulatory components of the complement system (complement factor H (CFH), and C3), enhancing complement activation. The previous finding that anti-CFH antibodies are prevalent in RA further highlights the importance of CFH in this disease, adding an extra mechanism that may dysregulate complement in RA. Taken together, we propose that citrullination-induced complement dysregulation and anti-CFH antibodies are key amplifiers that propagate damage and citrullination activity in the RA joint. We will examine this hypothesis in 3 Specific Aims. In Aim 1, we will use mass spectrometry and biochemical assays to define the structural and functional effects of citrullination on CFH and C3, as well as the effect of these modified proteins on the induction of the terminal complement complex, neutrophil hypercitrullination and B cell activation mediated by citrullinated C3dg. Aim 2 will use multiple reaction monitoring (MRM) to quantify citrullinated CFH and C3 in synovial fluid from RA and other arthritides to define their association with complement deposition and lytic activity in the joint. Aim 3 will determine whether anti-CFH antibodies participate in the dysregulation of complement in RA by defining their prevalence and clinical significance in RA, their association with complement activation, and their effect on CFH function. These studies will define novel interacting mechanisms of disease amplification relevant to sustain inflammation and aggravate damage in the rheumatoid joint. Furthermore, the studies will show that these pathways are active in vivo in RA, identifying markers and subgroups for precise therapeutic intervention.

项目摘要/摘要 了解驱动对自身抗原的免疫反应的机制是很高的优先级。在 类风湿关节炎（RA），蛋白质柠檬酸是免疫系统的主要目标。重要数据 在RA发病机理中暗示了抗硝化蛋白免疫反应，最近有证据表明 增强柠檬化的机制与最坏的疾病结果有关。虽然不同 我们发表的初步数据可能会促进RA中的柠檬化，这表明柠檬化 补体系统正在相互作用的途径，这些途径相互扩增以增强自身抗原 RA患者的大量子集的生产和免疫介导的损伤。因此，我们发现了细胞 补体介导的膜溶解是RA关节中蛋白质柠檬酸的有效诱导剂，并且 此过程与补体系统的关键调节组件的鞭打有关 （补体因子H（CFH）和C3），增强了补体激活。先前的抗CFH 抗体在RA中很普遍，进一步强调了CFH在该疾病中的重要性，增加了额外的 可能会使RA中补体失调的机制。综上 补体失调和抗CFH抗体是传播损伤和柠檬化的关键放大器 RA关节的活性。我们将在3个特定目标中检查这一假设。在AIM 1中，我们将使用质量 光谱法和生化测定法，以定义柠檬化对CFH和CFH的结构和功能效应 C3，以及这些修饰蛋白对末端补体复合物诱导的影响， 中性粒细胞过度乳腺癌和B细胞激活由柠檬硫化的C3DG介导。 AIM 2将使用多个 反应监测（MRM）以从RA和其他关节层的滑液中量化柠檬硫化的CFH和C3 定义他们与关节中补体沉积和裂解活性的关联。 AIM 3将确定 抗CFH抗体是否通过定义其患病率来参与RA中补体的失调 RA中的临床意义，它们与补体激活的关联及其对CFH功能的影响。 这些研究将定义与维持有关的疾病扩增的新型相互作用机制 炎症并加剧类风湿关节的损伤。此外，研究将表明这些 途径在RA中是活跃的体内，识别标记和亚组，以进行精确的治疗干预。