Epitopes described in "Peptide binding characteristics of the coeliac disease-associated DQ(alpha1*0501, beta1*0201) molecule."

Article Authors:Y van de Wal; Y M Kooy; J W Drijfhout; R Amons; F Koning
Article Title:Peptide binding characteristics of the coeliac disease-associated DQ(alpha1*0501, beta1*0201) molecule.
Reference Detail
Reference ID:315508
Abstract:Genetic susceptibility to coeliac disease (CD) is strongly associated with the expression of the HLA-DQ2 (alpha1(*)0501, beta1(*)0201) allele. There is evidence that this DQ2 molecule plays a role in the pathogenesis of CD as a restriction element for gliadin-specific T cells in the gut. However, it remains largely unclear which fragments of gliadin can actually be presented by the disease-associated DQ dimer. With a view to identifying possible CD-inducing antigens, we studied the peptide binding properties of DQ2. For this purpose, peptides bound to HLA-DQ2 were isolated and characterized. Dominant peptides were found to be derived from two self-proteins: in addition to several size-variants of the invariant chain (li)-derived CLIP peptide, a relatively large amount of an major histocompatibility complex (MHC) class I-derived peptide was found. Analogues of this naturally processed epitope (MHClalpha46 - 63) were tested in a cell-free peptide binding competition assay to investigate the requirements for binding to DQ2. First, a core sequence of 10 amino acids within the MHClalpha46 - 63 peptide was identified. By subsequent single amino acid substitution analysis of this core sequence, five putative anchor residues were identified at relative positions P1, P4, P6, P7, and P9. Replacement by the large, positively charged Lys at these positions resulted in a dramatic loss of binding. However, several other non-conservative substitutions had little or no discernable effect on the binding capacity of the peptides.
Affiliations:Department of Immunohaematology and Bloodbank, Leiden University Hospital, Leiden, The Netherlands.
Reference Type:Literature
PubMed ID:8753854
Journal Volume:44
Article Pages:246-53
Journal ISSN:0093-7711
Article Chemical List:HLA-DQ Antigens;HLA-DQ alpha-Chains;HLA-DQ beta-Chains;HLA-DQA1 antigen;HLA-DQbeta antigen
Article MeSH List:Amino Acid Sequence; Celiac Disease(genetics; immunology); Chromatography, High Pressure Liquid; Electrophoresis, Polyacrylamide Gel; HLA-DQ Antigens(genetics; metabolism); HLA-DQ alpha-Chains; HLA-DQ beta-Chains; Humans; Molecular Sequence Data; Protein Binding
Article Comments:Data originally imported from the HLA Ligand Database (http://hlaligand.ouhsc.edu/)
Curation Last Updated:2016-04-04 22:32:19