Effects of adenoviral-mediated IκB- expression on firm arrest, transmigration, and rolling of isolated blood monocytes on endothelial cells under physiological flow conditions. HUVEC were left untreated or were infected with rAd.IκB- and were stimulated with TNF- (100 U/mL) for 4 hours. Monocytes were perfused at a constant flow rate of 1.5 dyn/cm² after pretreatment with or without MoAbs to 4 and β2, 8-73 GRO-, or 9-76 MCP-1 peptide analogues (1 μg/mL each) for 30 minutes on ice before being perfused. (A) The firm attachment of monocytes to HUVEC was determined by counting the number of cells attached per field after a 5-minute period. (B) Cells undergoing spreading or transmigration were counted after 5 minutes and expressed as the percentage of cells initially attached. (C) The number of rolling cells within the field was counted in the last 30 seconds of the 5-minute period and was expressed as the percentage of cells interacting with endothelium. HUVEC were pretreated with a blocking (G1) or nonblocking P-selectin (S12) MoAb for 30 minutes at 37°C. Data are the mean ± SD of at least three independent experiments. *P < .05 versus uninfected control. **P < .05 versus rAd.IκB-–infected HUVEC.