IgA Nephropathy: Interventions with Generation of Nephritogenic Immune Complexes

IgA 肾病：生成肾炎性免疫复合物的干预措施

• 批准号: 8692360
• 负责人: JIRI F MESTECKY
• 金额: $ 33.18万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8692360
• 关键词: Affinity; Amino Acids; Antibodies; Antigen-Antibody Complex; Antigens; Autoantigens; Autoimmune Diseases; Autoimmune Process; Bacteriophages; Binding Sites; Biological; Biological Assay; Camels; Cell Proliferation; Complement; Complementarity Determining Regions; Data; Deposition; Diagnostic; Dialysis procedure; Disease; End stage renal failure; Epitopes; Galactose; Generations; Glomerulonephritis; Goals; Health Expenditures; Hematuria; Human; IgA1; Immune Complex Diseases; Immunoglobulin A; Immunoglobulin Constant Region; Immunoglobulin Fragments; Immunoglobulin G; Immunoglobulin Variable Region; In Vitro; Inflammatory; Injection of therapeutic agent; Injury; Intervention; Kidney; Kidney Diseases; Knowledge; Laboratories; Libraries; Light; Link; Literature; Llama; Mediating; Modeling; Molecular Weight; Morbidity - disease rate; Mus; Outcome; Pathogenesis; Pathway interactions; Patients; Peripheral Blood Lymphocyte; Play; Polysaccharides; Prevention; Property; Proteinuria; Reaction; Recurrence; Renal Replacement Therapy; Role; Series; Specificity; Structure of glomerular mesangium; Testing; Therapeutic; Transplant Recipients; Transplantation; United States; Water; antigen binding; base; crosslink; design; immunogenic; in vitro activity; in vivo; inhibitor/antagonist; mesangial cell; microorganism; molecular mass; mortality; nanobodies; nephrotoxicity; novel; prevent; public health relevance; research study; tool

DESCRIPTION (provided by applicant): IgA nephropathy (IgAN) is the most frequent glomerulonephritis in the world. Recently we have provided evidence for the autoimmune character of IgAN: nephritogenic immune complexes are formed in which IgA1 molecules with altered O-linked glycans in the unique hinge region (HR) of the heavy (H) chains serve as antigens that are recognized by naturally occurring, glycan-specific antibodies. We have also demonstrated that the pathogenic potential of IC formed is strongly dependent on the molecular mass: we demonstrated in vitro and in vivo that only large IC with molecular mass ~700-1000 kDa display nephritogenicity. In this application we propose to explore a novel, highly unconventional and emerging approach exploiting the potential of camelid single domain antibodies containing only the variable region of H chain (VHH fragments) as inhibitors of the formation of nephritogenic IC. VHH fragments of camelid antibodies contain the antigen- binding site contributed only by complementarity-determining regions of the H, but NOT light chains, display a high affinity for antigens, contain ~100 amino acids (~16 kDa), do not activate the complement cascade, are extremely stable, highly water-soluble, and not antigenic when injected in diverse species, including humans. Most importantly for our proposal, VHH are monovalent and consequently non-cross-linking, so that IC formed would be of low-molecular mass, and therefore, not nephritogenic. Furthermore, we have developed in vitro and in vivo assays which can be used for testing of the IC nephrotoxicity. Importantly, results emerging from our studies may be applicable and extended in the ultimate interference with the formation of pathogenic IC in other human IC diseases and VHH fragment may be also used as excellent diagnostic tools due their exquisite specificity and stability.

描述（由申请人提供）：IgA 肾病 (IgAN) 是世界上最常见的肾小球肾炎。最近，我们为 IgAN 的自身免疫特征提供了证据：形成肾炎性免疫复合物，其中重 (H) 链的独特铰链区 (HR) 中具有改变的 O 连接聚糖的 IgA1 分子作为抗原，被天然存在的聚糖特异性抗体识别。我们还证明了形成的 IC 的致病潜力强烈依赖于分子质量：我们在体外和体内证明，只有分子量约为 700-1000 kDa 的大 IC 才显示肾炎性。在本申请中，我们建议探索一种新颖的、非常规的新兴方法，利用仅含有 H 链可变区（VHH 片段）的骆驼单域抗体作为肾炎性 IC 形成抑制剂的潜力。骆驼抗体的 VHH 片段包含仅由 H 的互补决定区贡献的抗原结合位点，而不是轻链，对抗原表现出高亲和力，包含约 100 个氨基酸 (约 16 kDa)，不激活补体级联，极其稳定，高度水溶性，并且在注射到包括人类在内的不同物种中时不具有抗原性。对于我们的建议来说，最重要的是，VHH 是单价的，因此是非交联的，因此形成的 IC 具有低分子量，因此不会导致肾炎。此外，我们还开发了可用于测试 IC 肾毒性的体外和体内测定方法。重要的是，我们的研究结果可能适用并扩展，最终干扰其他人类IC疾病中致病性IC的形成，并且VHH片段由于其精致的特异性和稳定性也可以用作优秀的诊断工具。