Comparison of the relative avidity of adhesion of HEL cells and FLY cells to native ICAM4Fc and IC4D⁷³RFc.

Binding of cation-activated HEL cells or PMA+ cation–activated FLY cells was compared by titration of ICAM4Fc, IC4D⁷³RFc, and NCAMFc as described in “Materials and methods.” Adhesion to ICAM4Fc, IC4D⁷³RFc, or NCAMFc of HEL cells is indicated by triangles, crosses, or lines, respectively. Adhesion to ICAM4Fc, IC4D⁷³RFc, or NCAMFc of FLY cells is indicated by diamonds, squares, or stars, respectively.