title: Breaking the rules: the unconventional recognition of HLA-B27 by CD4+ T lymphocytes as an insight into the pathogenesis of the spondyloarthropathies.
abstract: Despite extensive research, it remains unclear why a small proportion of HLA- B27(+) individuals develop spondyloarthropathies (SpA). Because the function of HLA-B27, as a major histocompatibility complex (MHC) class I molecule, is peptide presentation to CD8(+) T cells, research has concentrated on the role of HLA-B27 as a restriction element for CD8(+) cytotoxic T lymphocytes in pathogenesis. However, findings in the B27-transgenic animal models, together with the identification of unusual processing and presentation features of HLA-B27, have raised alternative hypotheses for the pathogenic role of HLA-B27. One such hypothesis is that HLA-B27 can be recognized by CD4(+) T lymphocytes. Here we report the identification of such unusual cells, which break the conventional rules of MHC restriction, and propose a model for the role of such CD4(+) T cells in SpA.
authors.affiliation: University of Cambridge School of Clinical Medicine, Department of Medicine, Cambridge, UK. lhb22@cam.ac.uk
authors.forename: L H
authors.initials: LH
authors.lastname: Boyle
authors.forename: J S
authors.initials: JS
authors.lastname: Hill Gaston
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004195:Disease Models, Animal; D015796:HLA-B27 Antigen / Q000276:immunology*; D006801:Humans; D025242:Spondylarthropathies / Q000276:immunology*; D013329:Structure-Activity Relationship
chemical_list: D015796:HLA-B27 Antigen