Platelet Endothelial Cell Adhesion Molecule (CD31)

Abstract

Beginning in the mid-1980s, a number of groups working independently began to serologically characterize a series of vascular cell surface proteins that were subsequently designated as the CD-31 antigen. Ohto and colleagues, in 1985, documented that antibodies known as TM2 and TM3 bound to neutrophils and monocytes and inhibited their Chemotaxis toward endotoxin activated serum (Ohto et al. 1985). In the same year, van Mourik and associates described an antibody (HEC-75) against a 130 kDa antigen, then thought to be platelet glycoprotein IIa, that was present on endothelial cells and platelets (van Mourik etal. 1985). Goyert etal. (1986) subsequently raised an antibody (SG134) to an antigen on myelomonocytic stem cell lines that was able to identify stem cells of the myeloid lineage. All of these antibodies were found to belong to a cluster designated as CD31 (Knapp etal. 1989). In 1989, Muller and associates identified an antibody (hec7) that recognized a widely distributed endothelial cell junctional molecule of 130 kDa with unknown function (Muller etal. 1989). A molecule of similar size and distribution was isolated from bovine endothelial cells (endoCAM) that was also present on platelets and leukocytes. Antibodies against endoCAM were able to prevent initial endothelial cell-cell contacts (Albelda et al. 1990). In 1990, Newman et al. reported the molecular cloning of a 130kDa cell surface protein, designated PECAM-1 (platelet endothelial cell adhesion molecule-1), common to both platelets and endothelial cells (Newman etal. 1990). When it was found that antibodies directed against the hec7 antigen, endoCAM, and one of the previously identified myelomonocytic antigens (SG134) reacted with PECAM-1, it became evident that PECAM-1 was identical to the CD31 antigen.