Fig. 6.
To induce α4β1 expression on neutrophils, the cells were treated with DHCB and an exogenous chemotactic factor, FMLP. Perfusion of (▪) these cells or (▵) Ramos cells over VCAM-1–transfected L cells showed no interactions at 2 dyne/cm2. Reducing shear to less than 2 dyne/cm2 at 2-minute intervals caused neutrophils to tether to VCAM-1 transfectants (A) with very limited rolling (B). Untreated Ramos cells (known to express α4β1 ) interacted with VCAM-1 transfectants at very similar shears as the neutrophils but displayed primarily rolling (B), not adhesion (A).
