Interactions of E-selectin with lipid rafts in HUVECs enhance leukocyte rolling under flow. (A) Fixed neutrophils were perfused over unfixed or fixed IL-1β–stimulated HUVECs in isotonic or hypertonic medium at a wall shear stress of 1 dyne/cm2. The number of rolling neutrophils was measured after 4 minutes. The data represent the mean plus or minus SEM of 3 experiments. (B) IL-1β–stimulated HUVECs were pretreated in control isotonic medium or in medium containing MβCD or α-cyclodextrin (α-CD). Fixed neutrophils were then perfused in isotonic medium at a wall shear stress of 1 dyne/cm2. The number of rolling neutrophils was measured after 4 minutes. The data represent the mean plus or minus SEM of 5 experiments. (C) Fixed neutrophils were perfused over transfected CHO cells expressing wild-type E-selectin or IL-1β–stimulated HUVECs in isotonic medium; hypertonic medium; hypertonic medium after pretreatment of CHO cells or HUVECs with MβCD; hypertonic medium after pretreatment with MβCD and then 20% serum; hypertonic medium after pretreatment with α-cyclodextrin; or hypertonic medium after pretreatment with α-cyclodextrin and then 20% serum. The wall shear stress was 1 dyne/cm2. The number of rolling neutrophils was measured after 4 minutes. The data represent the mean plus or minus SEM of at least 3 experiments (*P < .05; **P < .01; ***P < .001, as measured by the unpaired t test).
