Rat P-Selectin Mediates Neutrophil-Platelet Interactions Via two Sites (23–30, 76–90) Located on Its Lectin-Like Domain.

P-selectin, (GMP-140/PADGEM, or CD62-P),1,2,3,4 has been shown to mediate adhesion of human leukocytes to activated platelets or endothelial cells.5,6,7 This adhesive receptor is a member of the selectin family which includes E-selectin (ELAM-1) and L-selectin (LAM-1, LECAM).8 The three members of the selectin family share extensive homologies in their lectin-, EGF- and complement-like domains. The lectin-like domain in human P-selectin appears to play a major role in mediating P-selectin interaction with leukocytes. Peptides derived from the lectin-like domain have been shown to block neutrophil interaction to thrombin-activated platelets9, endothelial cells or isolated P-selectin. We have previously shown 10 that LYP-20, an anti P-Selectin monoclonal antibody (MAb), inhibits human platelet aggregation and platelet-monocyte interactions. Moreover, LYP-20 recognises P-Selectin expressed by thrombin-activated rat platelets.11 Rats are extensively used as in vivo models of vascular injury. However, at this stage, little is known on the distribution and function of rat P-Selectin.