gp49BI-αvβ3 interaction inhibits antigen-induced mast cell activation

We have identified the integrin alpha (v)beta (3) as a ligand for mouse gp49B1,thus identifying a new class of ligand for a member of the family of inhibitory immunoreceptors that bear C2-type immunoglobulinlike domains,The specific interaction was shown by both cell-protein and cell-cell binding assays, In addition, we found that the interaction of alpha (v)beta (3) with gp49BI on bone marrow-derived mouse mast cells inhibited antigen-induced immunoglobulin E-mediated cell activation. Because neither gp49BI nor alpha (v)beta (3) exhibit substantive allelic variation, their newly appreciated interaction may reflect an innate pathway for down-regulating the activity of mast cells.