Hemopoietic and nonhemopoietic cell lines adhere to ICAM4Fc.

Adhesion assays were as described in “Materials and methods.” Results are input cells bound ± SD (n = 6). (A) Binding of hemopoietic cell lines (HEL, KG1a, THP1, IM9) and nonhemopoietic cell lines (FLY, HUVEC, 293, COS) to ICAM4Fc (▪) or to NCAMFc (control, ■). Activating conditions were cations (HEL, HUVEC) and PMA+ cations (IM9, KG1a, THP1, FLY, 293, COS). (B) Binding of cation-activated HEL cells (■) or PMA+ cation–activated FLY cells (▪) to ICAM4Fc in the presence of 2 mM EDTA, LDV peptide, or RGD peptide (500 μM). (C) Relative avidity of adhesion of hemopoietic cell lines to ICAM4Fc. Results are adjusted by subtraction of the baseline binding to NCAMFc (for maximal levels, see Table 1). Activation conditions were cations (HEL,♦; Raji) and PMA+ cations (Jurkat, ▪; THP1, ▴; Molt-4, ⋄; EBV-LCL, ▵; U937, ■). (D) Relative avidity of adhesion of nonhemopoietic cell lines to ICAM4Fc. Results are adjusted by subtraction of the baseline binding to NCAMFc (for maximal levels, see Table 2) Activation conditions were cations (HT29, ⋄) and PMA+ cations (DX3, ♦; FLY, ▪; SK-HEP1, ▴; HFFF, ■).