Dose-dependent effect of anti-CD31 antibodies on eosinophil adhesion to IL-4–stimulated vascular endothelial cells. IL-4–stimulated (▪) or unstimulated (□) HUVECs were preincubated with anti-CD31 MoAb NIH31-1 (31-1) or NIH31-2 (31-2) (1, 10, and 100 μg/mL) or control mouse IgG (Cont; 10 μg/mL) for 10 minutes at 37°C. After washing HUVECs, the adhesion assay of⁵¹Cr-labeled eosinophils to HUVECs was performed. Data are the means ± SD for 3 to 6 experiments.