T-cell receptor usage in alloreactivity against HLA-B*2703 reveals significant conservation of the antigenic structure of B*2705

Abstract

B*2703 is an exceptional HLA-B27 molecule in that it differs from the most common B*2705 subtype by a unique amino acid change (His59) altering N-terminal peptide anchorage. To assess how this unusual feature affects the antigenic structure of HLA-B27, TCR usage by alloreactive CTL raised against B*2703 from two individuals was analyzed. Only few CTL recognized B*2703 but not or at a lower level B*2705. Limited heterogeneity of these CTL was revealed by: 1) identity of TCR in two pairs of such CTL clones, 2) identity of β chains, paired to distinct a chains, in two clonotypes, and 3) almost identical fine specificity of these two clonotypes with site-specific HLA-B27 mutants. These results i..