Pretreatment with 3G3 antibody prevented fibrinogen consumption, tissue fibrin deposition, and fibrinolysis activation following a lethal dose of heat-inactivated S aureus injection in baboons. (A) Time course changes of fibrinogen levels. (B) Double immunostaining for fibrin (green) and platelet marker CD41 (red) in the lung and kidney of baboons challenged with LDSA (left) or with anti FXI antibody treatment (LDSA + 3G3; right). Nuclear counterstaining is shown in blue. Confocal images were captured on a Nikon Eclipse TE2000-U inverted microscope equipped with a Nikon C1 scanning head. Images were acquired and processed using EZ-C1 software (v 3.80; Nikon, Melville NY). Scale bars, 100 µm. (C-F) Time course changes of plasma markers of fibrinolysis: t-PA (C), PAI-1 (D), plasmin-antiplasmin complexes (E), and D-dimer (F). *P < .05, **P < .01, ***P < .001.