Characterizing the proteome of pathogenic IgA1-containing immune complexes in IgA Nephropathy

IgA 肾病中致病性 IgA1 免疫复合物的蛋白质组特征

• 批准号: 10673650
• 负责人: Mary Cunningham
• 金额: $ 3.87万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2024-07-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10673650
• 关键词: Antigen-Antibody Complex; Autoantibodies; Autoimmune; Awareness; Binding; Biological Markers; Blood; Blood Proteins; COVID-19; Calibration; Cell Proliferation; Chronic Kidney Failure; Circulation; Clinical; Complement; Complement Activation; Complex; Data; Dedications; Deposition; Development; Diagnosis; Dialysis procedure; Disease; Evaluation; Fractionation; Fright; Future; Galactose; Glomerular Capillary; Glomerulonephritis; Goals; Health Care Costs; Human; IGA Glomerulonephritis; IgA1; IgG autoantibodies; Immune response; Immunocompromised Host; Immunoglobulin G; Immunoglobulins; Injury; Injury to Kidney; Isotope Labeling; J-Chain Immunoglobulins; Kidney; Kidney Diseases; Kidney Failure; Kidney Transplantation; Knowledge; Learning; Manuscripts; Measures; Methods; Modeling; Molecular; Molecular Weight; Pathogenesis; Pathogenicity; Pathologic; Patients; Peptides; Polymers; Population; Production; Prognostic Marker; Progressive Disease; Proteins; Proteome; Proteomics; Protocols documentation; Renal Replacement Therapy; Research; Research Personnel; Sampling; Serum; Stable Disease; Testing; Tissues; Urine; biobank; cost; innovation; kidney biopsy; mesangial cell; monomer; novel; pandemic disease; patient population; screening; stoichiometry; therapeutic target

Project Abstract IgA Nephropathy (IgAN) is an autoimmune glomerulonephritis that frequently results in kidney failure. IgAN is characterized by elevated production of galactose-deficient immunoglobulin A1 (Gd-IgA1) being bound by an immunoglobulin G (IgG) autoantibody specific for Gd-IgA1 to form IgA1-associated immune complexes (IgA1- ICs) with additional proteins in blood. These complexes deposit in the glomerulus and cause kidney injury by activating mesangial cell proliferation and breakdown of glomerular capillaries allowing protein or blood in the urine. There is no worldwide screening and can only be diagnosed by renal biopsy. We know that the immunoglobulins and the undefined blood proteins are necessary to the nephritogenic activity of the high molecular weight IgA1-ICs, but we do not know what concentration, and variability of each protein nor the ratio of immunoglobulins necessary for complex formation. The primary goal of my study is to quantify and establish the ratios of immunoglobulins and blood proteins in the composition of IgA1-ICs in the serum of patients with IgAN of opposing clinical spectrum in comparison to healthy controls. Our collaborative team has observed that the addition of serum to the immunoglobulin nucleating factors is necessary for the formation of pathogenic ICs that activate human cultured mesangial cells. The overarching goal of this proposal is that quantitative analysis of serum IgA1-ICs will determine stoichiometry of immunoglobulins and other blood proteins involved in the formation of IgA1-ICs in both progressing and stable disease patients with IgAN. In my recently submitted manuscript, I identified 21 high-quality blood protein targets specifically enriched in IgA1-ICs isolated from IgAN patient serum. When comparing the identification of proteins and their corresponding enrichment in the IgA1-ICs to the other uncomplexed forms of IgA1 control fractions (monomeric and polymeric IgA), we observed that each fraction clustered by molecular form, showing the value of our sample prep and innovative fractionation of serum. Based on preliminary data, I hypothesize the ratio of IgA1 to IgG autoantibody is discreet and can be determined by targeted LC-MS quantitative analysis, polymeric IgA1 is the predominant molecular form of IgA1 involved in complex formation and complement cascade activation factors are present in complex composition at a higher ratio than immunoglobulins before deposition into the kidney. Throughout the global pandemic, the world has learned of the importance of disease screening, the variability of disease presentation, and the daily fear that immunocompromised populations live in. Being a researcher in IgA Nephropathy, I have been aware of these realities in IgAN patient populations prior to COVID-19. This has fueled my dedication to answering important questions in the IgAN field and understanding this crucial part of pathogenesis of IgA1-IC formation for the sake of future development of less-invasive screening methods or therapies using blood biomarkers for this currently unpredictable disease.

项目摘要 IgA肾病是一种自身免疫性肾小球肾炎，常导致肾功能衰竭。伊根是 特征是半乳糖缺乏的免疫球蛋白A1(Gd-IgA1)的产量增加 针对Gd-IgA1的免疫球蛋白G(Ig G)自身抗体形成Ig A1相关免疫复合体(Ig A1- ICS)和血液中的额外蛋白质。这些复合体沉积在肾小球中，通过以下方式导致肾脏损伤 激活系膜细胞的增殖和肾小球毛细血管的破坏，允许蛋白质或血液进入肾小球 尿液。目前还没有全球范围的筛查，只能通过肾活检来诊断。我们知道， 免疫球蛋白和未定义的血液蛋白是高血压病患者肾脏致炎活性所必需的 相对分子质量IgA1-ICs，但我们不知道每种蛋白质的浓度、变异性和比例 形成复合体所必需的免疫球蛋白。我研究的主要目标是量化和确定 慢性阻塞性肺疾病患者血清免疫球蛋白与血蛋白在Ig A1-ICs组成中的比值 与健康对照组相比，临床谱系相反的IGAN。我们的协作团队观察到 在免疫球蛋白核因子中加入血清是形成致病ICs所必需的 激活培养的人肾小球系膜细胞。这项建议首要目标是进行量化分析 将决定免疫球蛋白和其他参与免疫反应的血液蛋白的化学计量 进展期和稳定期IgA肾病患者IgA1-ICs的形成在我最近提交的 手稿，我确定了21个高质量的血液蛋白靶点，特别是从IgAN分离的IgA1-ICs中富含 病人血清。当比较IgA1-IC中蛋白质的鉴定及其相应的富集物时 对于其他未络合形式的IgA1控制组分(单体和聚合物IgA)，我们观察到每一种 按分子形式聚集的组分，显示了我们的样品制备和创新的血清分级的价值。 根据初步数据，我假设IgA1和Ig G自身抗体的比例是谨慎的，可以确定。 通过靶向LC-MS定量分析，聚合型IgA1是参与 复合体形成和补体级联激活因子在复合体成分中存在较高的 比免疫球蛋白沉积到肾脏之前的比例。在整个全球大流行期间，世界已经 了解了疾病筛查的重要性，疾病表现的可变性，以及日常生活中 免疫功能受损的人群生活在。作为一名研究IgA肾病的研究人员，我已经意识到了这些 新冠肺炎治疗前IgAN患者人群的现实情况。这促使我致力于回答重要的问题 免疫球蛋白A_1-IC形成过程中的问题及对其发病机制的认识 目前，使用血液生物标记物的侵入性较小的筛查方法或疗法的未来发展 无法预测的疾病。