Lacoste-Eleaume A S, Bleux C, Quéré P, Coudert F, Corbel C, Kanellopoulos-Langevin C
Département de Biologie du Développement, Institut Jacques Monod, CNRS, Paris, France.
Exp Cell Res. 1994 Jul;213(1):198-209. doi: 10.1006/excr.1994.1191.
We have analyzed the reactivity of a new mouse monoclonal antibody (mAb), 11C3, which identifies a cell marker detected on the surface of chicken thrombocytes. Tissue distribution studies have shown that only cells of the thrombocytic lineage in blood, spleen, and bone marrow are stained by 11C3. However, it does not react with other species such as quail, mouse, and man. The 11C3 mAb immunoprecipitates an heterodimeric molecule made of two bands with an apparent molecular weight of 112 and 90 kDa under nonreducing conditions and 112 and 26 kDa following reduction. This pattern of migration is similar to the one observed for members of the integrin family of cell adhesion molecules. We have used the previously described mAb AP-2, which is specific for the human platelet integrin GPIIb-IIIa and cross-reacts with chicken thrombocytes. We have shown that it immunoprecipitates two bands with an identical electrophoretic mobility. Cross-inhibition and immunodepletion studies reveal that the two antibodies recognize two different isoforms or two conformational variants of the same molecule. Moreover, our data demonstrate that in contrast with AP-2, 11C3 is a potent inducer of thrombocyte activation measured by cell aggregation, chemiluminescence, or release of [3H]serotonin. It also inhibits the adhesion of thrombin-activated thrombocytes to fibrinogen and, to a lesser degree, to fibronectin, in a dose-dependent manner. Altogether, these results indicate that this antibody identifies the avian homolog of the mammalian platelet integrin and fibrinogen receptor GPIIb-IIIa.
我们分析了一种新型小鼠单克隆抗体（mAb）11C3的反应性，该抗体可识别在鸡血小板表面检测到的一种细胞标志物。组织分布研究表明，只有血液、脾脏和骨髓中血小板系的细胞被11C3染色。然而，它不与鹌鹑、小鼠和人类等其他物种发生反应。在非还原条件下，11C3单克隆抗体免疫沉淀出一种由两条带组成的异二聚体分子，其表观分子量分别为112和90 kDa，还原后为112和26 kDa。这种迁移模式与细胞粘附分子整合素家族成员观察到的模式相似。我们使用了先前描述的mAb AP-2，它对人血小板整合素GPIIb-IIIa具有特异性，并与鸡血小板发生交叉反应。我们已经表明它免疫沉淀出两条具有相同电泳迁移率的带。交叉抑制和免疫耗竭研究表明，这两种抗体识别同一分子的两种不同异构体或两种构象变体。此外，我们的数据表明，与AP-2不同，11C3是通过细胞聚集、化学发光或[3H]血清素释放测量的血小板激活的有效诱导剂。它还以剂量依赖的方式抑制凝血酶激活的血小板与纤维蛋白原的粘附，并在较小程度上抑制与纤连蛋白的粘附。总之，这些结果表明该抗体识别哺乳动物血小板整合素和纤维蛋白原受体GPIIb-IIIa的禽类同源物。
