Figure 4.

(Left). Complement rescues the endocytosis of a triple Factor VIII (FVIII) FVIII^C1 mutant by dendritic cells. Recombinant wild-type (FVIII^HSQ) and mutated (FVIII^C1) B-domain-deleted FVIII (50 nM) were incubated for 1 hour (h) at 37°C in 20% normal serum (NS) or heat-inactivated serum (HIS). Mixtures were added on immature monocyte-derived dendritic cells (MO-DCs) (2.10⁵ cells in RPMI-1640) for 2 h at 4°C or 37°C. FVIII was then detected with an FITC-coupled anti-FVIII antibody directed to the A2 domain of FVIII. Mean fluorescence intensity (MFI) values measured at 4°C were subtracted from values measured at 37°C. Horizontal bars depict mean±Standard Deviation (SD) of 5 independent experiments. Statistical significance was assessed using the double-sided non-parametric Mann-Whitney test.