TF pathway and FVIII activation in vivo. (A) Carotid artery occlusion after injury by 7% (0.26 M) or 8% (0.3 M) FeCl3⋅6H2O in C57BL/6J mice treated with anti-TF 21E10, anti-FXI 14E11 MoAbs, or both, as indicated (n = 5-20 in different groups); control mice (panel C) were injected with buffer or isotype-matched nonimmune mouse IgG. (B) Femoral vein occlusion after injury by 4% (0.15 M) FeCl3⋅6H2O in mice (n = 3-7) receiving FVIII or FVIIIa (1.4 pmol bolus followed by 0.47 pmol/min for 15 min) before injury and MoAb treatment. Results in panel A (top) and panel B (dot plots; median and interquartile range) were analyzed with Kruskal-Wallis/Dunn tests; results in panel A (bottom) (dot plot; mean and 95% confidence interval) were analyzed with ANOVA/Tukey tests. (C) Fibrin formation in the femoral vein. Control mice were injected with phosphate-buffered saline (top left). FVIII injection does not prevent the antithrombotic effect of 9 µg/g anti-TF/65 ng/g anti-FXI MoAbs combined (top right). FVIIIa injection bypasses inhibition by this antibody combination (bottom left). FVIIIa cannot bypass inhibition by a full dose (125 ng/g) of anti-FXI MoAb alone (bottom right). (D) Representative TG (n = 3) induced by 0.15 pM rTF, 20 pM FIXa, or both in citrated human PRP (180 ⋅ 103 platelets/μL) recalcified with 18 mM CaCl2 at 37°C and containing 30 μg/mL CTI to block FXIIa and 40 µg/mL rabbit anti-TFPI IgG (left) or nonimmune IgG (right). (E) Representative TG (n = 2) induced by rTF, FIXa, or both as above in recalcified FIX-deficient PPP containing 50 μg/mL CTI and 180 ⋅ 103 normal washed platelets per microliter. *P < .05. **P < .01. ***P < .001.