Endothelial cell E-selectin and fibronectin are involved in adhesion of activated PBMCs. (A,B) HUVECs were preincubated with or without antibody against CD44, αvβ3 integrin, thrombospondin, fibronectin, E-selectin, or P-selectin. P3 protein was used as a nonreactive control antibody in panel B. HUVECs were washed and then tested for their ability to support adhesion of PBMCs activated with epi-treated SS RBCs. (A) Error bars show SEM of 4 different experiments measuring adhesion at a shear stress of 1 dyne/cm². *P < .001 compared with unstimulated PBMCs; **P < .01 compared with PBMCs preincubated with epi-treated SS RBCs. (B) Error bars show SEM of 3 different experiments measuring adhesion at a shear stress of 1 dyne/cm². *P < .001 compared with unstimulated PBMCs; **P < .01 compared with PBMCs preincubated with epi-treated SS RBCs.