Study on platelet adhesion molecule to inhibit aggregation.

血小板在血栓形成的初始阶段发挥着重要作用，但决定血小板黏附是导致血小板单层还是血小板血栓形成的过程却知之甚少。本研究旨在探讨血小板聚集和解聚过程中涉及的事件，特别是血小板表面黏附分子的表达机制。首先，我们阐明了血小板活化因子(PAF)聚集的血小板，即磷脂介体，可以被PAF拮抗剂WEB2086解聚，但不能被凝血酶解聚。血小板解聚的基础是黏附分子在细胞表面的表达，解离细胞与细胞之间的相互作用。此外，我们从小鼠脾细胞中获得了抗兔血小板抗体的克隆(My2-73)，它对血小板解聚有反应，具有不同于已报道的黏附分子的功能。…进一步将该单抗归类为Ig G_2a&gt；k型。该单抗以剂量依赖的方式阻止载铬的血小板与纤维蛋白原和胶原结合，其对刺激血小板的反应性降低，其表位不同于血小板表面的GMP-140和GPIIb/GPIIIa。125&gt；i使用乳过氧化物酶。用MY_2-73单抗、生物素-F(ab‘)_2兔抗鼠免疫球蛋白(H-L)抗体和亲和素-琼脂糖凝胶分离了分子量分别为120 kDa和110 kDa的分子量很少的标记黏附分子，并对大量的黏附分子进行了进一步的性质研究。较少

Platelets play an important role in the initial stage of thrombosis, but the processes that determine whether platelet adhesion results in a platelet monolayr or platelet thrombus formation is poorly understood. The purpose of the present study was to examine the events involved in platelet aggregation and desaggregation, especially the mechanism to express the adhesion molecule to platelet cell surface that responds to the desaggregation.First, in this study, we elucidated that platelets aggregated by platelet-activating factor (PAF), known as phospholipid mediator, are deaggregated by PAF antagonist WEB2086 but not those by thrombin. The platelet desaggregation was based on the expression of adhesion molecule to cell surface which dissociate cell-cell interaction.Furthermore, we obtained the clone (MY2-73) to produce anti-rabbit platelet antibody from mouse splenocyte, which responds to platelet desaggregation and functions as adhesion molecule different from others already reported. … More The monoclonal antibody was classified into IgG_<2a> type k. This monoclonal antibody prevented ^<51>Cr-loaded platelet to bind to fibrinogen and collagen in a dose-dependent manner, of which the reactivity to stimulated platelets decreased and the epitope is different from GMP-140 and GPIIb/GPIIIa on platelet cell surface.In order to purify the adhesion molecule recognized by the monoclonal antibody, we prepared the affinity column bound to the monoclonal antibody purified from mouse ascites, and solubillized rabbit platelet membrane proteins with CHAPS.The adhesion molecules purified by the affinity column were labelled with ^<125>I using lactoperoxidase. ^<125>I-labelled adhesion molecules immunoprecipitated with MY2-73 monoclonal antibody, biotin-F (ab')_2 rabbit anti-mouse IgG (H+L) antibody, avidin-agarose were separated on SDS-PAGE gel, of which the molecular weight were 120 and 110 kDa and the amounts were very small.We are in progress to further study the properties of adhesion molecule proteins after purification of high amounts these molecules. Less