Affinities of FVIII peptides identified on MoDCs. (A) The distribution of percentile-rank scores predicted by netMHCIIpan3.2 for all peptides found in the MAPPs assay for a single healthy donor, D1098 (black, shaded), compared with the distribution of percentile-rank scores for 1 × 10⁶ random strings of 15 aa (green), 1 × 10⁶ random 15 mers selected from the human proteome (red), and all 15 mers from FVIII and VWF (blue). Peptides found in the MAPPs assay were more likely to have high binding affinity to the patients’ alleles as shown by the greater probability of finding lower percentile rank scores for these peptide/MHC-II binding pairs. The other 3 distributions were close to flat which can be expected from a random distribution of peptides. (B) Peptides identified in the MAPPs assay following incubation with FL-rFVIII plus VWF. Location of the peptides is shown on the primary sequence of FVIII and they are color-coded for the subjects who provided the MoDCs. The gray backdrop shows the predicted number of subjects whose MHC-II variants would bind peptides at each location with high affinity (percentile rank <5%) based on netMHCIIpan predictions. Peptides found in the MAPPs assay were found in regions predicted to be binding regions by netMHCIIpan3.2. Not all regions predicted to be binding regions were found in the assay.