THE SPECIFICITY OF INTEGRIN LIGAND INTERACTIONS IN CULTURED HUMAN RENAL EPITHELIUM

Members of the beta1 integrin family are present at the basolateral me mbrane of human renal tubular epithelium in vivo and at the ventral su rfaces of cultured renal epithelial cells, at the sites appropriate fo r cell substratum adhesion. In this study we have proven that these mo lecules are indeed functional in mediating cell substratum attachment in normal human renal epithelium by using monoclonal antibodies to int egrin alpha subunits to block initial cell attachment. The importance of arginine-glycine-aspartic acid (RGD) recognition by cell surface re ceptors in various extracellular ligands was also examined using synth etic peptides. RGDS peptide strongly inhibited attachment to plain pla stic or fibronectin-coated substrata but had no effect on cell adhesio n to laminin-coated coverslips.