IdeS inhibits thrombus formation and TF synthesis induced by 5B9 and UFH. (A) Representative images corresponding to areas of 0.1 mm² vWF-coated microfluidic channels perfused (5 minutes, 500 s⁻¹; 20 dyn/cm²) with recalcified WB incubated for 30 minutes in the presence of UFH (0.5 IU/mL) without or with 5B9 alone (40 µg/mL) or 5B9 + IdeS (0.02 U/µg of IgG). In experiments with IdeS, WB containing 5B9 was preincubated with IdeS for 6 minutes at 37°C before the addition of UFH. Platelets are shown in green (DiOC6), fibrin(ogen) is in red (Alexa Fluor 647–labeled fibrinogen), and leukocytes are blue (Hoechst 33342, DNA dye). Experiments were performed with WB from 2 healthy donors. (B) Percentages of area covered by platelet/leukocyte aggregates and fibrin(ogen) after infusion of UFH, UFH + 5B9 without or with IdeS. (C) Representative microscopy images of a clot observed after perfusion (5 minutes, 500 s⁻¹) with recalcified WB incubated for 30 minutes with 5B9 (40 µg/mL) and UFH (0.5 IU/mL). Platelets are shown in green (DiOC6), leukocytes are blue (Hoechst), and fibrin was visualized (purple staining) after adding a Cy3-labeled antifibrin specific monoclonal Ab (clone 59D8) (5 µg/mL). Images were acquired using a ORCA-R2 digital CCD camera with a 20× objective; scale bars, 20 µm. (D) Relative TF mRNA synthesis (mean ± SEM) after the addition of 5B9 (50 µg/mL) or LPS (1 µg/mL) to WB and incubated without or with IdeS (0.02 U/µg IgG; 6 minutes at 37°C) before the addition of UFH (0.5 IU/mL). *P < .05; NS, not significant.