The HLA-DP2 protein binds the immunodominant epitope from myelin basic protein, MBP85-99, with high affinity
Research output: Contribution to journal › Journal article › Research › peer-review
Myelin basic protein (MBP) is a candidate autoantigen in multiple sclerosis (MS). The immunodominant epitope for T-cell responses is assigned to the amino acid sequence MBP84-102, which binds to human leukocyte antigen (HLA)-DR2a (DRB5*0101) and HLA-DR2b (DRB1*1501) of the HLA-DR2 haplotype carrying the strongest genetic association with MS. In contrast with HLA-DR and -DQ molecules, HLA-DP molecules are poorly characterized with respect to the binding of self-peptides. We show here that HLA-DP2 binds MBP85-99 with high affinity, and that the amino acid residues in position MBP91, MBP92 and MBP93 are influencing the binding, as shown by alanine scans. We further used a series of truncated peptides to identify the core of the binding. Moving the frame along the peptide from residues 87-97 to 89-99 progressively decreased the binding affinity for HLA-DP2, while moving further towards the C-terminal completely abrogated the binding of peptides to HLA-DP2. The data suggest that the docking of the MBP85-99 peptide into the HLA-DP2 groove is dependent on MBP88V and MBP89V and may use either of them as primary anchor for the p1 position. HLA-DP2 might thus present the MBP85-99 peptide in the same register as the HLA-DRB1*1501, where the MBP89V is preferred as the p1 anchor. Notably, full-length MBP was able to compete for peptide binding with an affinity similar to that seen for the high-affinity binding peptides, DRa170-83 and IIP53-65. In summary, the HLA-DP2 molecule binds the immunodominant epitope in MS, MBP85-99, possibly in more than one register.
Original language | English |
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Journal | HLA |
Volume | 77 |
Issue number | 3 |
Pages (from-to) | 229-34 |
Number of pages | 6 |
ISSN | 2059-2302 |
DOIs | |
Publication status | Published - 1 Mar 2011 |
ID: 40224069