Binding and activity of TM fusion proteins on mouse endothelial cells.

<p>(a) Anti-PECAM scFv/TM and (b) anti-ICAM scFv/TM bind to their respective ligands on MS1 cells. Binding is inhibited by excess of parental anti-PECAM-1 and anti-ICAM-1 antibodies. (c) Anti-ICAM scFv/TM demonstrates ∼15-fold greater activity per binding site on MS1 cells, as compared to its PECAM-anchored counterpart. (d) Antibody blockade of EPCR results in a ∼50% decrease in APC generation by endogenous TM and anti-ICAM scFv/TM, but not anti-PECAM scFv/TM. All experiments were done in triplicate. Data shown are mean ± SD.