Mouse anti Human vitronectin receptor CD51

T-lymphocyte clones NKI-M7 detect a melanoma-associated proteoglycan (MW greater than 450-250 kDa) and a molecular complex, which under reducing conditions consists of 4 compounds of 120, 95, 29 and 25 kDa respectively. NKI-M7 reacts with cultured melanomas melanomas in frozen sections. The antigen detected by NKI-M7 is strongly associated with the adhesion and cytoplasmic spreading of melanoma cells to plastic surfaces and monolayers of vascular endothelial cells. NKI-M7 blocks fibronectin-induced chemotaxic motility and chemokinesis of melanoma cells. In addition to their membrane localization, the antigens detected by NKI-M7are abundant in extracellular adhesion plaques deposited by cultured melanoma cells. NKI-M7 stains primary tumors heterogeneously, whereas metastases are homogeneously stained.