Lack of carboxyl-terminal tyrosine distinguishes the B*2706-bound peptide repertoire from those of B*2704 and other HLA-B27 subtypes associated with ankylosing spondylitis

Tissue Antigens. 1997 Mar;49(3 Pt 1):215-21. doi: 10.1111/j.1399-0039.1997.tb02741.x.


B*2704 and B*2706 are two closely related HLA-B27 subtypes, which differ from the common B*2705 by the Asp > Ser77, Val > Glu152, and Ala > Gly211 amino acid changes. In addition, B*2706 differs from B*2704 by the His > Asp114 and Asp > Tyr116 changes. In spite of their similarity B*2704, but not B*2706, was associated to ankylosing spondylitis in a same population. We have carried out pool sequence analyses of the peptides naturally bound to each of these subtypes, and of several individual peptide ligands. B*2704 and B*2706 shared with B*2705, among other features, their selectivity for Arg2 and their allowance for some aliphatic and aromatic C-terminal residues in their bound peptides. The main features that distinguished both subtypes from B*2705 were: 1) their failure to present peptides with C-terminal basic residues, and 2) their allowance for both polar and nonpolar residues at peptide position 3. A major difference between B*2704 and B*2706 was that C-terminal Tyr was prominent among the peptides bound to B*2704, but was not detected among those from B*2706. The use of Tyr as a C-terminal anchor motif is the only functional feature shared by the disease-associated B*2705, B*2702, and B*2704 subtypes that is absent in B*2706. This suggests that the ability of HLA-B27 to present peptides with C-terminal Tyr might be critical for its association to spondyloarthropathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigen Presentation
  • Binding Sites
  • Cell Line
  • HLA-B27 Antigen / genetics
  • HLA-B27 Antigen / immunology*
  • Humans
  • Peptides / chemistry
  • Peptides / genetics
  • Peptides / immunology*
  • Spondylitis, Ankylosing / immunology*
  • Tyrosine / chemistry
  • Tyrosine / immunology*


  • HLA-B27 Antigen
  • Peptides
  • Tyrosine