Mapping of the MAPPs assay derived peptides on FVIII structure. (A) Surface representation of the FVIII structure (PDB ID 2R7E) with the regions identified to be VWF-binding sites^10,39  (pink). (B) Structure depicted in panel A with the regions yielding MHC-II–presented FVIII-derived peptides unique to FL-rFVIII (green). Peptides in green (see domain labels for peptide location) were identified on MoDCs incubated with FL-rFVIII plus pdVWF but not identified when MoDCs from the same subject were incubated with pdFVIII plus pdVWF (ie, protected in the pdFVIII protein). The FVIII domains are identified on the figure in bold letters.