NEUTROPHILS ROLL ON E-SELECTIN

Using flow conditions that simulate those in post capillary venules, w e have found that neutrophils attach and roll on a substrate bearing p urified E-selectin. E-selectin resembles P-selectin (CD62) with regard to the dependence of attachment efficiency on wall shear stress and s electin density. In contrast, once attached, neutrophils form rolling adhesionson E-selectin that are much stronger than those on P-selectin . Rolling velocities on E-selectin are slower and have less variance t han on P-selectin. With increasing shear stress, rolling velocities re ach a plateau level that is dependent on E-selectin density, suggestin g that the number of receptor-ligand bonds and the bond dissociation r ate limit rolling velocity, and that the bonds are not broken by the a pplied force.