PROTEIN S, C4BBP, AND THREE COAGULANT MODELS

这些研究的主要目的是继续研究影响 蛋白 S 和 C4b 结合蛋白对弥散性血管内 致死性大肠杆菌脓毒症模型中的凝血反应。 自从这两个 因素还影响微血管血栓和深静脉血栓 对炎症刺激的反应，我们计划研究这两者的作用 这些模型中的因素也是如此。 中心假设是蛋白 S 具有两种保护功能。 第一个是作为活化蛋白 C 的抗凝辅助因子， 第二个是作为 C4b 结合蛋白的抗补体辅助因子。 相反，蛋白质 S 相对于 C4bBP 的不足会导致 炎症和凝血反应的放大，因为 它们相互联系、相互驱动。 因此蛋白质 S 的减少 消耗或通过过量的 C4bBP 中和可以离开 促炎和促凝血活性不受抑制，除非有 足够的蛋白质 S 来服务于其抗补体和 抗凝血功能。 这个假设的某些方面可以 体内测试。使用弥散性血管内凝血模型 针对致命的大肠杆菌，我们将使用 C4bBP/蛋白 S 复合物进行干预 或蛋白质 S 并监测其对生理和实验室的影响 参数。 其中包括补体系统的 C5b-9 和 C4bc 标记 激活、凝血酶-抗凝血酶复合物和纤维蛋白原标记物 凝血剂激活以及细胞因子和蛋白 C 的成分 途径（即游离和结合蛋白 S、蛋白 C 和 C4bBP）。 我们会 确定是否存在与细胞结合的 C4bBP/蛋白 S 复合物池 膜上带有针对蛋白质 S 的 Gla 结构域的抗体，通过这些抗体 复合物可能被锚定。 我们将通过分析来监测这一情况 输注抗体后血浆中复合物的增加。 我们 还将研究放射性标记复合物向这些膜的募集 炎症刺激（即大肠杆菌、TNF）之前和之后。 我们会 研究蛋白质 S 的哪些结构域参与适当的 抗体。 我们将用抗C3b抗体进行干预并比较其 与 C4bBP/蛋白 S 复合物的抗补体作用。 使用亚致死微血管血栓反应模型 大肠杆菌和 C4bBP 以及对 TNF 和 C4bBP 的深静脉血栓反应， 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，病理学 这两个模型的响应将分为几个阶段。 这包括 实验室标记物与光学和电子显微镜的相关性 组织的研究。 这些研究应该提供有关以下方面的见解： 大肠杆菌脓毒症炎症与凝血的关系 为诊断和治疗提供新的视角。

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.