The HLA-A0207 Peptide Binding Repertoire is Limited to a Subset of the A0201 Repertoire

ABSTRACT: Quantitative A∗0207 peptide binding assays have been developed utilizing HLA transfected cells and affinity purified molecules. By using a panel of single substitution analog peptides, it was demonstrated that A∗0207 binds peptides with main anchor specificity at position 2 and the C-terminus similar to A∗0201. Previous data indicating that A∗0207 (but not A∗0201) also requires the presence of D or P in position 3 of its peptide ligands was confirmed by the analysis of additional single substituted analogs. Finally, by analyzing the A∗0201 and A∗0207 binding capacities of panels of unrelated synthetic peptides, it was found that 8/15 (53.3%) A∗0201 binders with D or P in position 3 bound A∗0207, while only 5/72 (6.9%) A∗0201 binders without D or P in position 3 also bound A∗0207. Together, these data indicate that although A∗0207 may be included amongst A2 supertype alleles, its peptide binding repertoire is largely limited to a subset of that bound by A∗0201.