Fig. 10. Expression of laminin-binding integrins on transfected K562 cells increases CD151 cell surface expression. Flow cytometric analysis of wild-type K562 cells endogenously expressing 5ß1 and transfected K562 also expressing Vß1, 3ß1, 6ß1, 6ß4, 7X1ß1 or 7X2ß1. Solid lines in the left panels indicate staining with anti-integrin antibodies: anti-5 mAb Sam-1 (K562 cells), anti-V mAb 13C2 (K562-V), anti-3 mAb J143 (K562-3), anti-6 mAb GoH3 (K562-6), anti-ß4 mAb 439-9B (K562-6ß4) and anti-7 mAb CA25 (K562-7BX1 and K562-7BX2). Staining of cells with anti-CD151 antibodies is shown in the right panels. Solid lines represent staining of cells with mAb TS151R and broken lines with mAb P48. A negative control (dotted line) with secondary goat anti-mouse or rat IgG alone is shown in each panel. R represents the ratio of the mean fluorescence intensity of cells stained with mAb P48 and with secondary antibody alone. A three- to sixfold increase of CD151 expression is observed in transfected cells that ectopically express laminin-binding integrins. The TS151R epitope is masked in all cells expressing one of the laminin-binding integrins.