A monoclonal antibody directed against a granule membrane glycoprotein (GMP-140/PADGEM, P-selectin, CD62P) inhibits ristocetin-induced platelet aggregation
A monoclonal antibody directed against a granule membrane glycoprotein (GMP-140/PADGEM, P-selectin, CD62P) inhibits ristocetin-induced platelet aggregation
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DOI：
10.1046/j.1365-2141.1996.d01-1485.x
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发表时间：
1996-02-01
影响因子：
6.5
通讯作者：
McGregor, JL
中科院分区：
文献类型：
--
作者：
Boukerche, H;RuchaudSparagano, MH;McGregor, JL
P-选择素（也称为CD 62、GMP-140、PADGEM、CD 62 P）是最近描述的由活化的血小板和内皮细胞表达的参与白细胞细胞粘附的血管粘附受体家族的成员。本研究的目的是表征一种新的针对活化的人血小板的单克隆抗体（LYP 7），其抑制瑞斯托霉素诱导的血小板聚集，免疫吸附亲和层析和免疫沉淀研究表明，LYP 7（IgG（1））与表面标记的糖蛋白（GP）结合，在还原过程中，GP的表观分子量（M（r））从138 kD（位于GPIIb之下）至148 kD（GPIIb α之上）。LYP 7和抗P-选择素单克隆抗体S12免疫沉淀出相同的条带。用ELISA法检测P-选择素与LYP 7和S12单克隆抗体的结合。I-125标记的LYP 7的结合位点，其在凝血酶刺激（2 U/ml）洗涤的血小板上大大增加（10825+/-2886，平均值+/-SD）（Kd =1.5+/-0.5 nM）与静息血小板相比（2801+/-1278，平均值+/-SD）（Kd =1.5+/-0.6nM），在取自灰色血小板综合征患者或Glanzmann血小板无力症患者的凝血酶刺激血小板上正常。LYP 7（IgG（1）、F（ab '）（2）或Fab片段）以剂量依赖性方式抑制瑞斯托霉素诱导的血小板聚集，而不影响血管性血友病（vWf）因子的结合。然而，李斯特菌诱导的甲醛固定的血小板凝集不受单克隆抗体LYP 7的影响。此外，凝血酶活化的血小板与中性粒细胞的结合被单克隆抗体LYP 7抑制。这些结果有力地表明，P-选择素，通过促进细胞-细胞接触，可能在血小板-血小板相互作用中发挥积极作用。
P-selectin (also called CD62, GMP-140, PADGEM, CD62P) is a recently described member of a family of vascular adhesion receptors expressed by activated platelets and endothelial cells that are involved in leucocyte cell adhesion. The aim of this study was to characterize a new monoclonal antibody (LYP7) directed against activated human blood platelets that inhibits ristocetin-induced platelet aggregation, Immunoadsorbent affinity chromatography and immunoprecipitation studies showed that LYP7 (IgG(1)) bound a surface-labelled glycoprotein (GP) which changed its apparent molecular mass (M(r)) on reduction from 138kD (situated below GPIIb) to 148kD (above GPIIb alpha). LYP7 and S12, a monoclonal antibody directed against P-selectin immunoprecipitated the same band. Using ELISA assay, purified P-selectin was shown to bind LYP7 and S12 monoclonal antibodies. Binding sites of I-125-labelled LYP7, which was greatly increased on thrombin-stimulated (2 U/ml) washed platelets (10825+/-2886, mean +/-SD) (K-d=1.5+/-0.5nM) compared to resting platelets (2801+/-1278, mean +/-SD) (K-d=1.5+/-0.6nM), was found to be normal on thrombin-stimulated platelets taken from a patient with grey platelet syndrome or a patient with Glanzmann thrombasthenia. LYP7 (IgG(1), F(ab')(2) or Fab fragments) inhibited ristocetin-induced platelet aggregation of platelets in a dose-dependent fashion without affecting the binding of von Willebrand (vWf) factor. However, agglutination of formaldehyde-fixed platelets induced by ristocetin was not affected by monoclonal antibody LYP7. In addition, the binding of thrombin-activated platelets to neutrophils was inhibited by monoclonal antibody LYP7. These results strongly suggest that P-selectin, by promoting cell-cell contact, may play an active role in platelet-platelet interactions.