Figure 5.

FXII is important in thrombin generation induced by apoptotic cells. (A–E) Thrombin generation triggered by apoptotic cells in normal plasma was analyzed as described in the Section “Materials and Methods.” Representative data are shown on the left, and accumulated data with statistical analysis are shown on the right. (A) Apoptotic cells were pretreated with 5 µg/mL BSA or annexin V, and then used in a thrombin generation assay (n = 3). (B) Apoptotic cells were pretreated with an anti-FXII antibody C6B7 or anti-tissue factor (TF) blocking antibody (4501; 5 µg/mL each), and then used in a thrombin generation assay (n = 3). (C) The thrombin generation assay was performed in normal plasma, FXII-deficient plasma, and FXII-deficient plasma reconstituted with human FXII (n = 3). (D) Phosphatidylcholine (PC) or phosphatidylserine (PS) liposome-coated beads were used to stimulate thrombin generation in normal plasma. Some samples using PS liposome-coated beads were also incubated with 5 µg/mL C6B7 (n = 3). (E) Apoptotic cells pretreated with PBS, 100 U/mL Calf intestinal alkaline phosphatase (CIAP), or 0.01% DNase, before thrombin generation was measured. **p < 0.01; ***p < 0.001.