Leukocyte rolling in the cremaster muscle of triple-selectin–null mice 5 hours after exteriorization.
Leukocyte rolling in the postcapillary venules of the cremaster muscle was severely inhibited (P < .001) compared with the wild type in mice null for all 3 selectin genes. This was reflected by both the rolling flux (A) and rolling flux fraction (B) in mutant and control (+/+) mice. Rolling was completely absent at time points up to 5 hours, with or without pretreatment with TNF-α. A small amount of residual rolling was present at this time, with or without the pretreatment. These results are similar to those in E/P double mutants. The residual rolling observed at 5 hours in both double-mutant and triple-mutant mice was eliminated completely by intravenous administration of a mAb (PS/2) blocking α4-integrin, indicating that the residual rolling is dependent on α4-integrin.
