CD46: Protecting the Host from Complement Attack

CD46：保护宿主免受补体攻击

• 批准号: 7036880
• 负责人: John Atkinson
• 金额: $ 34.35万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7036880
• 关键词: Neisseriaceae; Streptococcus pyogenes; X ray crystallography; active sites; biological signal transduction; complement inhibitors; complement pathway; decay accelerating factor; fertility; genetically modified animals; laboratory mouse; nuclear magnetic resonance spectroscopy; phosphorylation; protein structure function; protein tyrosine kinase; tissue /cell culture; yeast two hybrid system

DESCRIPTION (provided by applicant): Membrane cofactor protein (MCP, CD46) is a complement regulatory protein that binds C3b and C4b and serves as a cofactor for their limited proteolytic degradation. A major development during the past grant cycle was the discovery that mutations in CD46 predispose to atypical hemolytlc uremic syndrome (aHUS). This finding has an immediate impact on treatment options since renal transplantation would be curative in CD46 deficiency. This is especially significant since aHUS can be a life-threatening condition that recurs in patients (usually young children) with about 50% developing renal failure. Atypical HUS is now recognized as a disease of complement deregulation due to mutations in complement regulatory proteins. We will address how CD46 deficiency predisposes to aHUS. A major goal of this grant is to characterize CD46's regulatory activity in situ. In patients with aHUS and their families, we will 1) establish a facility to identify mutations and determine the functional repertoire of the mutant proteins; 2) use model systems (CHO cells expressing the mutant proteins, EB virus transformed human B lymphocytes from aHUS families, and human endothelial cells), assess Inhibitory activity in situ; RNAi will be employed to create cells with a specific inhibitor deficiency state; 3) employ scFv-complement regulator(s) chimeras to target inhibitors to RBCs and endothelial cells in order to correct the deficiency and to define the most potent inhibitory mix of regulators to block complement activation; 4) monitor membrane movements of regulators as they are cross-linked with Abs and pathogens and in response to complement activation. A theme underlying these specific alms is to explore the process whereby the host limits complement activation on altered and injured self cells. This phenomenon we have termed TRACS, for targeted and restricted activation of the complement system, is little studied. We propose that the profile of complement activation on self-tissue has unique purposes and distinct features compared to its activation on microbes. Our long term goal is to understand how this is accomplished using CD46 deficiency In aHUS as the Illustrative example. Our proposal will help define how deficiency of the complement regulator CD46 predisposes to human disease hemolytic uremic syndrome as well as develop ways to deliver regulators to treat such conditions

描述（由申请人提供）：膜辅因子蛋白（MCP，CD46）是一种结合C3B和C4B的补体调节蛋白，并用作其有限的蛋白水解降解的辅助因子。在过去的赠款周期中的一个主要发展是，发现CD46中的突变易感到非典型溶血性尿毒症综合征（AHUS）。这一发现对治疗方案有直接的影响，因为肾移植将在CD46缺乏症中治愈。这尤其重要，因为Ahus可能是一种威胁生命的疾病，该疾病在患者（通常是幼儿）中复发，大约50％的肾衰竭。现在，非典型HUS被认为是由于补体调节蛋白突变引起的补体放松管制疾病。我们将解决CD46缺乏症如何容易患河流。该赠款的主要目标是表征CD46的原位监管活动。在Ahus及其家人的患者中，我们将1）建立一个设施来识别突变并确定突变蛋白的功能库； 2）使用模型系统（表达突变蛋白的CHO细胞，EB病毒转化了来自Ahus家族的人类B淋巴细胞和人内皮细胞），评估原位抑制活性； RNAi将被用来创建具有特定抑制剂缺乏状态的细胞。 3）采用SCFV汇编调节剂（S）嵌合体靶向RBC和内皮细胞靶向抑制剂，以纠正缺乏并定义调节剂最有效的抑制作用，以阻止补体激活； 4）监测调节剂的膜运动与ABS和病原体交联，并响应补体激活。这些特定施舍的主题是探索宿主限制在改变和受伤的自我细胞上激活的过程。我们称这种现象称为tracs，用于补体系统的靶向和限制激活，很少研究。我们建议，与在微生物上的激活相比，自我组织上补体激活的特征具有独特的目的和不同的特征。我们的长期目标是了解如何使用AHU中的CD46缺乏症来实现这一目标。我们的建议将有助于定义补体调节剂CD46的缺乏症如何易于人类疾病溶血性尿毒症综合征，并开发出提供调节剂以治疗这种情况的方法