NADPH oxidase internalization by the TF-integrin β1 complex. (A) Time course of ROS production measured in WT CD115⁺ spleen monocytes preloaded with H₂DCFDA stimulated with aPL HL5B or the TLR7/8 ligand R848 in the presence of the indicated coagulation protease inhibitors; mean ± SD. n = 6. (B) Live cell imaging of aPL HL5B internalization in CD115⁺ cells of the indicated mouse strains. Scale bar = 5 µm. (C) Catalytic subunit of NOX2 (gp91phox) colocalization with EEA1⁺ endosomes in CD115⁺ spleen cells from integrin β1^−/− and TF^ΔCT mice. Scale bar = 5 µm. (D) Quantification of ROS production in CD115⁺ splenocytes of the indicated mouse strains after stimulation with aPL HL5B or TLR7/8 agonist R848; mean ± SD. n = 6. *P = .0001; 2-way ANOVA, Dunnett multiple-comparison test. (E) TFPI is required for endosomal ROS production. ROS generation in TFPI^ΔK1 or WT monocytes was measured after stimulation with aPL HL5B in the presence or absence of niflumic acid (0.1 mM). Endosomal ROS production after subtraction of nonendosomal ROS measured in the presence of niflumic acid is shown; mean ± SD. n = 4. (F) ROS production was measured in cells preloaded with H₂DCFDA in human monocytes stimulated with HL5B either alone or in the presence of αTFPI (20 µg/mL) added 15 minutes before aPL stimulation; mean ± SD. n = 6.