EMP binding to THP-1 cells.

THP-1 cells incubated with EMPs for 15 minutes (C, D) or control THP-1 cells (A, B) were immunostained according to the avidin–biotin–peroxidase procedure and analyzed by microscopy as described in “Materials and methods.” Primary antibody was 3End mAbs (B, D) or isotype-matched control (A, C) used at 50 μg/mL. The ratio of EMP to THP-1 cells was 50:1. Brown coloration on THP-1 cells incubated with EMPs indicated the presence of endothelial antigens. Observations are representative of 4 independent experiments. Original magnification: × 50.