CONTROL MECHANISMS IN HEMOSTASIS

本提案的目的包括三个主要目标： 1. 为了表征FVIII介导的血小板粘附的性质， 血管内皮下 我们将比较FVIII和 去唾液酸化的FVIII（ASVIII）对去内皮化的兔和人血管， 内皮细胞，内皮细胞外基质，胶原 以及FVIII和ASVIII在调节血小板聚集中的作用 在这些系统中， 我们还将比较ASVIII约束力， 未受刺激的血小板与FVIII结合至来自 正常人、阿司匹林化正常人与贮水池病 综合征和血小板减少症患者。 我们将研究 我们的单克隆抗体与血小板GpIb和GpIb的FVIII和ASVIII结合， GpIIb-IIIa复合物。 2. 确定狼疮抗凝剂的作用机制，以及 与阴离子反应的循环抗体的止血意义 磷脂 我们将继续研究阴离子磷脂 狼疮抗凝剂特异性及其与抗DNA的比较 狼疮患者体内的抗体 我们将研究PGI 2的抑制 狼疮抗凝剂在培养内皮细胞中的合成 通过等电聚焦或亲和层析纯化， PS，PA-琼脂糖凝胶。 我们将研究 低凝血酶原血症，见于27%的狼疮抗凝剂患者， 在狼疮患者中进行125 I-凝血酶原周转研究， 抗凝血剂 3. 探讨血小板与内皮细胞的关系 膜蛋白 我们将描述人类内皮细胞 膜组分与单克隆和多克隆抗体反应， 血小板GpIIIa，确定该成分是否具有P1 A1抗原性 特异性（如血小板GpIIIa），并研究是否结合这些 抗体改变内皮细胞功能，特别是PGI 2的产生。 我们将研究血栓性疾病患者血清中的IgG组分， 血小板减少性紫癜，谁可能有抗体针对 内皮细胞和/或血小板，用于对内皮细胞的反应性， 细胞，特别是针对GpIIIa组分。 我们要搜查 对于内皮细胞之间共有的其他膜成分， 血小板

The aims of this proposal cover 3 major objectives: 1. To characterize the nature of FVIII-mediated platelet adhesion to vascular subendothelium. We shall compare the binding of FVIII and desialylated FVIII (ASVIII) to deendothelialized rabbit and human vessels, cultured endothelial cells, endothelial cell extracellular matrix, collagen and microfibrils, and the effect of FVIII and ASVIII in modulating platelet adhesion in these systems. We shall also compare ASVIII binding to unstimulated platelets with FVIII binding to stimulated platelets from normals, aspirinized normals, and storage pool disease, Bernard-Soulier syndrome and thrombasthenic patients. We shall study the inhibition of FVIII and ASVIII binding by our monoclonal antibodies to platelet GpIb and the GpIIb-IIIa complex. 2. To determine the mechanism(s) of action of lupus anticoagulants, and the hemostatic significance of circulating antibodies reactive with anionic phospholipids. We shall continue studies of the anionic phospholipid specificity of lupus anticoagulants and compare them with anti-DNA antibodies from patients with lupus. We shall study inhibition of PGI2 synthesis in cultured endothelial cells produced by lupus anticoagulants purified by isoelectric focusing or affinity chromatography on PS,PA-Sepharose. We shall investigate the mechanism of hypoprothrombinemia, seen in 27% of patients with lupus anticoagulants by doing 125I-prothrombin turnover studies in lupus patients with and without anticoagulants. 3. To investigate the relationship between platelet and endothelial cell membrane proteins. We shall characterize the human endothelial cell membrane component reactive with monoclonal and polyclonal antibodies to platelet GpIIIa, determine whether this component has P1A1 antigenic specificity (like platelet GpIIIa), and study whether the binding of these antibodies alters endothelial cell function, particularly PGI2 production. We shall study IgG fractions from sera of patients with thrombotic thrombocytopenia purpura, who may have antibodies directed toward endothelial cells and/or platelets, for reactivity against endothelial cells, and against the GpIIIa component, in particular. We shall search for other membrane components in common between endothelial cells and platelets.