Dual role of complement in post-ischemic inflammation and recovery

描述（由申请人提供）：缺血/再灌注损伤（IRI）是与几种临床病症（例如，出血性休克、严重烧伤、败血症、心肌梗塞、中风、移植功能障碍/排斥）。已知补体在缺血和再灌注（IR）后的无菌炎症和损伤中起关键作用，但最近已变得明显的是，补体在某些缺血事件后的组织修复和再生中也起重要作用。提出的研究的目标是更好地理解IR后的补体激活事件，并剖析补体效应机制在IRI和组织修复/再生中的双重作用。与这些目标同时，提出开发和表征一种新的靶向补体抑制策略，其保护免受炎症和损伤，同时促进组织修复和再生。先前和初步的数据表明，类似的补体激活和效应机制参与了多个器官和组织的损伤和修复/再生过程。然而，我们的模型将是肝IRI和再生，因为小鼠模型已经被很好地表征，并且因为临床意义。总体工作假设是补体被天然自身反应性IgM激活，该IgM结合缺血后暴露的新表位，并且末端膜攻击复合物（MAC）在缺血再灌注损伤（IRI）中起关键作用，而更近端的激活产物对于修复和再生是重要的。我们已经分离出一组新型自身反应性IgM mAb，并将使用这些mAb研究IR或部分肝切除术后发生的免疫学变化（新表位暴露）和补体激活事件。我们还将利用在级联反应中不同点发挥作用的补体抑制剂来研究参与炎症、损伤和再生的补体效应机制。我们还将研究补体在吞噬细胞清除凋亡和坏死细胞中的作用，以及这一过程如何影响炎症环境和随后的组织损伤和修复。最后，我们将通过分析临床标本来研究小鼠模型中产生的数据与人类的关系。这些研究的另一个目标是开发一种新的靶向策略， 利用单链抗体将补体抑制剂局部递送至缺血后新表位。

DESCRIPTION (provided by applicant): Ischemia/reperfusion injury (IRI) is a major clinical problem associated with several clinical conditions (e.g., hemorrhagic shock, severe burns, sepsis, myocardial infarction, stroke, transplant dysfunction/rejection). Complement is known to play a key role in sterile inflammation and injury following ischemia and reperfusion (IR), but more recently it has become evident that complement also plays important roles in tissue repair and regeneration following certain ischemic events. A goal of the proposed studies is to better understand the complement activation event following IR, and to dissect the dual role of complement effector mechanisms in IRI and tissue repair/regeneration. Concurrent with these goals, it is proposed to develop and characterize a novel targeted complement inhibitory strategy that protects against inflammation and injury while promoting tissue repair and regeneration. Previous and preliminary data indicate similar complement activation and effector mechanisms are involved in the injury and repair/regeneration processes of multiple organs and tissues. However, our model will be hepatic IRI and regeneration since mouse models have been well characterized and because of clinical significance. The overall working hypothesis is that complement is activated by natural self-reactive IgM that binds to neoepitopes exposed after ischemia, and that the terminal membrane attack complex (MAC) plays a key role in ischemia reperfusion injury (IRI) whereas more proximal activation products are important for repair and regeneration. We have isolated a panel of novel self-reactive IgM mAbs, and will use these mAbs to investigate immunological changes (neoepitope exposure) and the complement activation event that occurs after either IR or partial hepatectomy. We will also utilize complement inhibitors that function at different points in the cascade to investigate complement effector mechanisms involved in inflammation, injury and regeneration. We will also investigate the role of complement in phagocytic clearance of apoptotic and necrotic cells, and how this process impacts the inflammatory environment and subsequent tissue injury and repair. Finally, we will investigate how data generated in our mouse models relates to humans by analysis of clinical specimens. An additional goal of these studies is to develop a novel targeting strategy to locally deliver a complement inhibitor to post-ischemic neoepitopes utilizing single chain antibodies.