Distinct localization patterns for FcRn and FcRγ binding mutants of rFVIIIFc in the absence of VWF.

<p>Sections from FVIII/VWF-DKO mice lacking both VWF and FVIII, stained for Kupffer cells (A’, B’, C’, D’, CD68, red) show strong punctate vesicular staining of both rFVIII (A, A’, green) and the rFVIIIFc-IHH mutant (C, C’, green) that is incompetent to bind FcRn. This punctate staining is associated with hepatocytes and not LSEC. In contrast, both rFVIIIFc (B, B’, green) and the Fcγ-receptor binding mutant, rFVIIIFc-N297A (D, D’ green) localize to the liver sinusoid. In the absence of VWF, rFVIII, rFVIIIFc and the rFVIIIFc mutants are not associated with Kupffer cells (CD68, red). (CV, central vein; S, sinusoid; KC, Kupffer cell and HC, plate of hepatocytes; scale bar, 20 μm).