PROTEIN S AND C4BBP IN THREE COAGULANT MODELS

这些研究的主要目的是继续研究 蛋白S和C4 b结合蛋白对弥漫性血管内 在致死性大肠杆菌脓毒症模型中的凝血反应。 由于这两 影响微血管血栓形成和深静脉血栓形成的因素 对炎症刺激的反应，我们计划研究这两个 这些模型中的因素。 核心假设是蛋白S具有两种保护功能。 第一种是作为活化蛋白C的抗凝辅助因子， 第二是作为C4 b结合蛋白的抗补体辅因子。 相反，蛋白S相对于C4 bBP的不足可导致 炎症和凝血反应的放大， 它们相互联系，相互推动。 因此，蛋白S的减少， 消耗或通过过量C4 bBP中和可以离开 促炎和促凝血活性未经检查，除非 是足够的蛋白S既服务于其抗补体， 抗凝血功能。 这一假设的某些方面可以 在体内测试。用弥散性血管内凝血模型 针对致死性大肠杆菌，我们将用C4 bBP/蛋白S复合物进行干预 或蛋白S，并监测其对生理和实验室的影响 参数 这些包括补体系统的C5 b-9和C4 bc标记物 活化，凝血酶-抗凝血酶复合物和纤维蛋白原标志物， 凝血激活以及细胞因子和蛋白C组分 路径（即。游离和结合蛋白S、蛋白C和C4 bBP）。 我们将 确定是否存在与细胞结合的C4 bBP/蛋白S复合物池 膜与抗体的Gla结构域的蛋白S，这些 复合体可以被锚定。 我们将通过检测 抗体输注后血浆中复合物的增加。 我们 我也将研究放射性标记的复合物对这些膜的募集 在炎症刺激之前和之后（即，大肠杆菌，TNF）。 我们将 研究蛋白S的哪些结构域参与了适当的 抗体的 我们将用抗C3 b抗体进行干预， 抗补体作用与C4 bBP/蛋白S复合物的抗补体作用相同。 利用微血管血栓反应模型， 大肠杆菌和C4 bBP以及对TNF和C4 bBP的深静脉血栓形成反应， 我们将探讨一些与上述相同的系统， 每个型号都有独特的功能。 我们将研究组织因子的作用 前者为血小板，后者为组织因子和白细胞。 后者 为了给这些研究更多的视角， 这两个模型的响应将分为几个阶段。 这包括 实验室标记物与光镜和电镜的相关性 组织的研究。 这些研究应该提供深入了解 大肠杆菌败血症中炎症和凝血的关系， 为诊断和治疗提供了新的视角。

The main objective of these studies is to continue study of the influence of protein S and C4b-binding protein on the disseminated intravascular coagulant response in the lethal E.coli model of sepsis. Since these two factors also influence microvascular thrombotic and deep vein thrombotic responses to inflammatory stimuli, we plan to study the role of these two factors in these models as well. The central hypotheses is that protein S has two protective functions. The first is as an anticoagulant cofactor for activated protein C and the second is as an anticomplement cofactor for C4b-binding protein. Conversely, insufficiency of protein S relative to C4bBP can lead to an amplification of both the inflammatory and coagulant responses because they are linked and drive each other. Thus reduction of protein S by consumption or by neutralization by excess C4bBP can leave pro-inflammatory as well as procoagulant activity unchecked unless there is sufficient protein S to serve both its anticomplement and anticoagulant functions. Certain aspects of this hypothesis can be tested in vivo. Using the model of disseminated intravascular coagulant response to lethal E.coli we will intervene with C4bBP/protein S complex or protein S and monitor their effects on physiologic and laboratory parameters. These include C5b-9 and C4bc markers of complement system activation, thrombin-antithrombin complexes and fibrinogen markers of coagulant activation as well as cytokine and components of the protein C pathway (ie. free and bound protein S, protein C and C4bBP). We will determine if there is a pool of C4bBP/protein S complex bound to cell membranes with antibodies to the Gla domain of protein S by which these complexes might be anchored. We will monitor this by assaying for increases of the complex in plasma following infusion of antibodies. We also will study recruitment of radiolabeled complexes to these membranes before and after an inflammatory stimulus (ie. E.coli, TNF). We will study which domains of protein S participate with the appropriate antibodies. We will intervene with anti-C3b antibody and compare its anti -complement effects with those of the C4bBP/protein S complex. Using the models of the microvascular thrombotic response to sublethal E.coli and C4bBP and the deep vein thrombotic response to TNF and C4bBP, we will probe some of the same systems described above as well as features unique to each model. We will examine the role of tissue factor and platelets in the former and that of tissue factor and leukocytes in the latter. To give these studies more perspective, the pathologic responses of these two models will be divided into stages. This includes correlation of laboratory markers with light and electron microscopic studies of tissue. These studies should provide insights into the relationship between inflammation and coagulation in E.coli sepsis and offer new perspectives on diagnosis and treatment.