HMEC-1 cell adhesion to factor XIIIa is dependent on β₁-containing integrins and integrin _vβ₃.

Cell adhesion assays were conducted using immobilized thrombin-activated factor XIIIa. HMEC-1 cells were preincubated with the indicated concentration of antibodies directed against β₂-containing integrins (black bars), α_vβ₃ (gray bars), β₁-containing integrins (striped bars), or α_vβ₃ plus β₁ (hatched bars) for 30 minutes at 37°C in 5% CO₂, and allowed to attach for 40 minutes to wells coated with 7.5 μg/mL factor XIIIa. Adherent HMEC-1 cells were fixed, stained with toluidine blue, solubilized with 2% SDS, and assayed for absorbance at 650 nm. Background binding to uncoated wells was subtracted from each value. Each bar represents the mean of 6 determinations ± SD.