Figure 5.

Fibrinogen γ^390–396A fails to support α_Mβ₂-dependent adhesion of monocytes, macrophages, or the monocytoid cell line, THP-1. (A) Comparative analysis of primary human blood monocyte adhesion to immobilized WT and γ^390–396A fibrinogen (coating concentration 2 ∝g/ml). Specificity of integrin-mediated binding was established by preincubation of cells with blocking α_M- or β₂-specific mAb’s (44a and IB4, respectively). The nonblocking α_M mAb, OKM1, was used as a control. (B) Comparative analysis of mouse peritoneal macrophage adhesion to WT and γ^390–396A fibrinogen. The blocking Ab M1/70 was used to demonstrate α_Mβ₂-specificity. (C) THP-1 cell adhesion as a function of fibrinogen coating concentration using either WT or γ^390–396A fibrinogen. (D) Adhesion of THP-1 cells to WT or γ^390–396A fibrinogen in the presence of either EDTA or α_Mβ₂ Ab, M1/70. The data shown are means ± SD. fl, fluorescence.