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J. Hrdinová et al.
and HLA-DQ. This is exemplified by the peptide derived from the CUB1 domain of ADAMTS13, spanning amino acid sequence 1206-1222 – RGPGQADCAVAIGRPLG, that was identified on both HLA-DR and HLA-DQ of donors 2 and 3 (Figure 2). However, in the case of donor 9 this peptide was found on HLA-DQ but not on HLA-DR. Similarly, two peptides derived from the metalloprotease and CUB2 domains of ADAMTS13 were identified both on HLA-DR and HLA-DQ for donors 8 and 9, respectively.
Our data show that, while HLA-DQ is involved in ADAMTS13, HLA-DR is more likely to be presenting pep- tides from ADAMTS13, and that there is considerable overlap between the repertoires of ADAMTS13-derived peptides presented on HLA-DR and HLA-DQ.
Evaluation of ADAMTS13 peptide immunogenicity using bioinformatic approaches
The above findings document which ADAMTS13 pep-
A
B
Figure 1. Relative presentation of total peptides and ADAMTS13- derived peptides on HLA-DR and HLA-DQ. (A) Total number of peptides identified after elution from either HLA-DR or HLA-DQ. (B) The ADAMTS13-derived peptides found on either HLA-DR or HLA- DQ. Statistical differences in peptide presentation were deter- mined using the non-parametric Mann-Whitney U-test. **P<0.01. ns: not significant.
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Figure 2. ADAMTS13-derived peptides presented on HLA-DR and HLA-DQ. Peptides identified to be presented by DCs of 9 studied donors on HLA-DR and HLA-DQ. Longest amino acid sequence of overlapping peptides is shown in the third column. Amino acids that are predicted to be a part of the peptide-MHC-II binding core are shown in bold. Blue: peptides identified only in HLA-DR condition. Red: peptides identified exclusively in HLA-DQ condition. Green: peptides identified in both HLA-DR and HLA-DQ conditions.
haematologica | 2018; 103(6)