HUMAN PROTEOLYTIC FOR IgA NEPHROPATHY

人类蛋白水解物治疗 IgA 肾病

• 批准号: 8601292
• 负责人: ROBERT F BALINT
• 金额: $ 9.99万
• 依托单位: CYTODESIGN, INC.
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8601292
• 关键词: Affect; Anaphylaxis; Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Antigen-Antibody Complex; Antigens; Antihypertensive Agents; Bacteria; Blood Circulation; Cells; Chronic; Cleaved cell; Clinical; Clostridium difficile; Complement Factor B; Complement Factor D; Complex; Deposition; Dialysis procedure; Disease; Dose; End stage renal failure; Engineering; Enzymes; Epitopes; Escherichia coli; Excision; Exotoxins; Family; Funding; Galium; Gene Library; Glomerulonephritis; Goals; Haemophilus influenzae; Human; Human Engineering; IgA1; Immune; Immunoglobulin A; Immunoglobulin G; Inflammation; Injection of therapeutic agent; Kidney; Kidney Diseases; Lead; Libraries; Mediating; Modeling; Mus; Mutagenesis; Patients; Peptide Hydrolases; Phagocytosis; Phase; Phenotype; Plasmapheresis; Positioning Attribute; Process; Reagent; Recovery; Regimen; Renal Circulation; Renal function; Resolution; Rest; Risk; Serine Protease; Specificity; Structure of glomerular mesangium; Substrate Specificity; System; Therapeutic; Therapeutic Uses; Time; Toxic effect; Transplantation; Validation; Variant; Work; advanced disease; chymotrypsin; design; effective therapy; flu; immunogenic; immunogenicity; novel; periplasm; prevent; public health relevance; research clinical testing; response; restoration; scaffold; screening; sensor; success

DESCRIPTION (provided by applicant): Immunoglobulin A nephropathy (IgAN) is the most common form of glomerulonephritis worldwide. The disease is characterized by progressive deposition of abnormal immune complexes of polyclonal IgA in the mesangia of the glomeruli, causing chronic inflammation and progressive damage to the kidneys, evolving into end-stage renal disease in up to 40% of cases, for which dialysis or transplantation is required. There are currently no effective treatments for incipient IgAN, and advanced disease is treated primarily with anti-inflammatory and anti-hypertensive regimens prior to dialysis or transplantation. However, several lines of evidence have indicated that reduction of IgA deposits in the kidney is typically associated with a clinical and pathological resolution of glomerulonephritis, and vice versa. Furthermore, removal of IgA complexes from the circulation by plasmapheresis or transplantation of an IgAN kidney into a non-IgAN recipient has lead to disappearance of kidney deposits, and restoration of kidney function. Thus, any treatment aimed at removing and/or preventing pathogenic IgA deposits in the kidneys could lead to substantial recovery of kidney function, and would therefore be highly desirable. One strategy has sought to exploit IgA-cleaving proteases, which are secreted by mucosal bacteria. The protease from H influenzae was effective in removing circulating and mesangial IgA deposits in mice injected with immune complexes containing human IgA1 in amounts comparable to the IgA1 concentration in the human circulation. Thus, such a strategy seems promising. However, a serious drawback of the bacterial protease is its potential immunogenicity. The risks of anaphylaxis and loss of efficacy will probably be unacceptable, since large doses will likely be required to deal with the abundance of IgA in the human circulation, and since IgAN patients will continue to produce "IgAN-ogenic" IgA, and will therefore need periodic IgA protease treatments for the rest of their lives. Thus, the ultimate success of this strategy will depend on engineering an IgA1-specific proteolytic activity on a human protease scaffold that is stable in the human circulation, which is the aim of the present proposal. To facilitate the engineering of target-cleaving activities on human protease scaffolds, a proprietary proteolytic activity sensor has been developed, which, when co-expressed in cells with mutagenic gene libraries of a protease scaffold, confers a selectable phenotype on cells expressing target-cleaving variants of the scaffold in quantitative proportion to their activities. We will use this system to engineer human IgA-cleaving activity int human complement factor D (hFD), a circulatory protease that is uniquely suited to serve as a scaffold for engineering proteases for human therapy. It is hoped that treatment with such a protease will facilitate the clearance of IgA immune complexes from the glomerular mesangium and allow the restoration of normal kidney function in IgAN patients.

描述（由申请人提供）： 免疫球蛋白 A 肾病 (IgAN) 是全世界最常见的肾小球肾炎形式。该疾病的特点是肾小球系膜中异常的多克隆IgA免疫复合物进行性沉积，引起慢性炎症和肾脏进行性损伤，高达40%的病例演变成终末期肾病，需要透析或移植。目前尚无针对初期 IgAN 的有效治疗方法，晚期疾病主要在透析或移植前采用抗炎和抗高血压方案进行治疗。然而，多项证据表明，肾脏中 IgA 沉积的减少通常与肾小球肾炎的临床和病理缓解相关，反之亦然。此外，通过血浆置换或将 IgAN 肾脏移植到非 IgAN 受体中从循环中去除 IgA 复合物，导致肾脏沉积物消失和肾功能恢复。因此，任何旨在去除和/或预防肾脏中致病性IgA沉积物的治疗都可以导致肾功能的实质性恢复，因此将是非常需要的。一种策略是利用粘膜细菌分泌的 IgA 裂解蛋白酶。在注射了含有人 IgA1 的免疫复合物的小鼠中，来自流感嗜血杆菌的蛋白酶可有效去除循环和系膜 IgA 沉积物，其量与人体循环中的 IgA1 浓度相当。因此，这样的策略似乎很有前途。然而，细菌蛋白酶的一个严重缺点是其潜在的免疫原性。过敏反应和疗效丧失的风险可能是不可接受的，因为可能需要大剂量来处理人体循环中丰富的 IgA，并且 IgAN 患者将继续产生“IgAN 源性”IgA，因此在余生中需要定期进行 IgA 蛋白酶治疗。因此，该策略的最终成功将取决于在人体循环中稳定的人蛋白酶支架上设计 IgA1 特异性蛋白水解活性，即 本提案的目的。为了促进人类蛋白酶支架上靶标切割活性的工程化，开发了一种专有的蛋白水解活性传感器，当其在具有蛋白酶支架的诱变基因文库的细胞中共表达时，赋予表达支架靶标切割变体的细胞以与其活性成比例的可选择表型。我们将使用该系统来设计人类补体因子 D (hFD) 中的人类 IgA 裂解活性，hFD 是一种循环蛋白酶，特别适合用作人类治疗的工程蛋白酶的支架。希望用这种蛋白酶进行治疗将促进IgA免疫复合物从肾小球系膜中的清除，并使IgAN患者恢复正常肾功能。