Experimental affinities of FVIII2194-2205 peptides for 10 HLA-DR proteins
| . | Reference peptide* . | FVIII2194-2205 . | F2196A . | F2196K . | M2199A . | M2199R . |
|---|---|---|---|---|---|---|
| DRB1*01:01 | 0.3 ± 0.0 | 0.3 ± 0.0 | >50 | >50 | 39.8 ± 3.2 | >50 |
| DRB1*03:01 | 3.9 ± 0.7 | >50 | >50 | >50 | 28.5 ± 2.9 | >50 |
| DRB1*04:01 | 1.1 ± 0.2 | 36.3 ± 4.8 | >50 | >50 | >50 | >50 |
| DRB1*04:04 | 0.02 ± 0.00 | 39.1 ± 5.0 | >50 | >50 | >50 | >50 |
| DRB1*07:01 | 0.3 ± 0.1 | >50 | >50 | >50 | >50 | >50 |
| DRB1*09:01 | 0.1 ± 0.0 | 42.0 ± 5.2 | >50 | >50 | 3.5 ± 0.3 | >50 |
| DRB1*10:01 | 2.9 ± 0.4 | 7.3 ± 0.7 | >50 | >50 | >50 | >50 |
| DRB1*11:01 | 4.4 ± 0.7 | >50 | >50 | >50 | >50 | >50 |
| DRB1*11:04 | 3.8 ± 0.5 | >50 | >50 | >50 | >50 | >50 |
| DRB1*15:01 | 0.06 ± 0.01 | 5.8 ± 0.5 | >50 | >50 | >50 | >50 |
| . | Reference peptide* . | FVIII2194-2205 . | F2196A . | F2196K . | M2199A . | M2199R . |
|---|---|---|---|---|---|---|
| DRB1*01:01 | 0.3 ± 0.0 | 0.3 ± 0.0 | >50 | >50 | 39.8 ± 3.2 | >50 |
| DRB1*03:01 | 3.9 ± 0.7 | >50 | >50 | >50 | 28.5 ± 2.9 | >50 |
| DRB1*04:01 | 1.1 ± 0.2 | 36.3 ± 4.8 | >50 | >50 | >50 | >50 |
| DRB1*04:04 | 0.02 ± 0.00 | 39.1 ± 5.0 | >50 | >50 | >50 | >50 |
| DRB1*07:01 | 0.3 ± 0.1 | >50 | >50 | >50 | >50 | >50 |
| DRB1*09:01 | 0.1 ± 0.0 | 42.0 ± 5.2 | >50 | >50 | 3.5 ± 0.3 | >50 |
| DRB1*10:01 | 2.9 ± 0.4 | 7.3 ± 0.7 | >50 | >50 | >50 | >50 |
| DRB1*11:01 | 4.4 ± 0.7 | >50 | >50 | >50 | >50 | >50 |
| DRB1*11:04 | 3.8 ± 0.5 | >50 | >50 | >50 | >50 | >50 |
| DRB1*15:01 | 0.06 ± 0.01 | 5.8 ± 0.5 | >50 | >50 | >50 | >50 |
Affinities were determined using a competitive binding assay. HLA-DR proteins were incubated with 0.05, 0.1, 0.5, 1, 5, 10, and 50 μM FVIII peptides plus the relevant biotinylated reference peptides as competitors for each HLA-DR (supplemental Table 1) and immobilized in wells coated with the anti-DR antibody L243. After washing, the remaining bound biotinylated peptide was labeled using europium-conjugated streptavidin and quantified using a time-resolved fluorometer.
Numbers are IC50 values (concentration in μM displacing 50% of the reference peptide) ± standard error (SE). IC50 values were calculated from sigmoidal binding curves using SigmaPlot. Reference peptide affinities were similar to those reported previously.32,71