Cell adhesion under flow. A total of 0.4 × 106/mL HL-60 cells cultured with 50μM 4F-GalNAc or vehicle control for 38 hours were perfused over either L-E/I (E-selectin) cell monolayers (A-C) or reconstituted P-selectin–bearing surfaces (D-F) in a parallel-plate flow chamber. Fluid shear was step increased from 0.35 dyn/cm2 to 3 and 6 dyn/cm2 in the case of E-selectin experiments as indicated (A inset). Wall shear stress was constant at 0.4 dyn/cm2 in P-selectin runs (D inset). Representative binned histograms of rolling velocities in vehicle control (A,D) and 4F-GalNAc–treated samples (B,E) are presented. (C,F) Rolling velocity data at indicated shear rates. 4F-GalNAc increased cell rolling velocity by 2.4-fold for E- and 2-fold for P-selectin–mediated rolling. *P < .05 with respect to vehicle control.
