COMPLEMENT CONVERTASE: ASSEMBLY, FUNCTION AND REGULATION

描述(由申请人提供)：补体替代激活途径(AP)是人类疾病和损伤状态下组织损伤的主要原因。旨在抑制有害补体活性的治疗药物已经开始出现在临床环境中。补体C3转换酶是补体激活的关键酶。补体相关的疾病和损伤可以追溯到转换酶装配不当(例如自身免疫)和转换酶调节功能障碍(例如非典型HUS、老年性黄斑变性)。控制转换酶的组装和调控是预防补体相关损伤的治疗策略的关键。我们的长期目标是设计新的方法来预防或抑制有害补体。在补体激活的三种途径中，替代途径(AP)尤其与多种疾病和损伤状态有关。该建议针对AP，特别是针对配基蛋白，这是AP转换酶所特有的一种成分，其功能尚未完全了解。最近，我们和其他人利用动物模型系统证明了备解素是改善AP依赖发病机制的一个有前途的治疗靶点。为了了解备解素功能的机制基础，并开发一种基于备解素的治疗策略来抑制AP依赖的补体活性，我们提出了以下具体目标：1.使用体外模型系统来表征备解素模式识别活性对C激活的贡献。具体目的2.阐明备解素在AP依赖致病动物模型中的作用(S)。具体目的3.开发抗备解素试剂，用于治疗抑制病理性AP依赖的C活性。我们期望这项工作的结果有可能具有高度的翻译性，并对旨在控制补体替代途径的治疗策略产生重大影响。 与公共健康相关：补体蛋白保护我们免受感染微生物的侵袭，但在其他情况下，它们可能会导致严重的、潜在威胁生命的组织损伤。这项拟议的研究将为此类病例的成功治疗干预提供新的策略和工具。

DESCRIPTION (provided by applicant): The complement alternative activation pathway (AP) is a principal cause of tissue damage in human diseases and injury states. Therapeutic agents designed to inhibit harmful complement activity have begun to emerge in the clinical setting. The C3 convertases are the key enzymes of complement activation. Complement-related disease and injury can be traced both to inappropriate convertase assembly (e.g. autoimmunity), and to convertase regulator dysfunction (e.g. atypical HUS, age-related macular degeneration). The control of convertase assembly and regulation is the key to therapeutic strategies for prevention of complement-related damage. Our long-range goal is to design new approaches for the prevention or inhibition of harmful complement. Of the three complement activation pathways, the alternative pathway (AP) in particular has been implicated in numerous disease and injury states. This proposal is directed to the AP and specifically to properdin, a component unique to the AP convertases and whose functions are not yet fully understood. Recently we, and others, have employed animal model systems to demonstrate that properdin is a promising therapeutic target for the amelioration of AP-dependent pathogenesis. In order to understand the mechanistic basis of properdin function and to develop a properdin-based strategy for the therapeutic inhibition of AP- dependent complement activity, we propose the following SPECIFIC AIMS: Specific Aim 1. Use in vitro model systems to characterize the contribution of properdin pattern recognition activity to C activation. Specific Aim 2. Elucidate the role(s) of properdin in animal models of AP-dependent pathogenesis. Specific Aim 3. Develop anti-properdin reagents for the therapeutic inhibition of pathologic AP-dependent C activity. We expect the results from this work to have the potential to be highly translational and to significantly impact therapeutic strategies aimed at controlling the complement alternative pathway. PUBLIC HEALTH RELEVANCE: The complement proteins protect us from infectious microorganisms but under other circumstances they can cause severe and potentially life-threatening tissue damage. The proposed research will provide new strategies and tools for successful therapeutic intervention in such cases.