title: The recognition of abnormal forms of HLA-B27 by CD4+ T cells.
abstract: The MHC class I molecule, HLA-B27 can be expressed as a number of non-conventional forms, in addition to conventional HLA-B27 heterodimers presenting peptide. This has lead to new avenues of research to explain the association of this molecule with SpA. Surprisingly, HLA-B27 transgenic animal models implicated CD4+ T cells, which conventionally interact with MHC class II molecules, not MHC class I molecules, in the pathogenesis of SpA. One hypothesis to explain these finding is that non-conventional forms of HLA-B27, specifically HLA-B27 homodimers, might mimic MHC class II molecules and be recognised by CD4+ T cells. We investigated whether CD4+ T cells from AS patients can interact with HLA-B27, discovering that indeed CD4+ T cells can interact with various forms of HLA-B27. Here we discuss how such interactions between HLA-B27 and CD4+ T cells could occur in vivo and potential contributions of such interactions to the pathogenesis of SpA.
authors.affiliation: Cambridge Institute of Medical Research, University of Cambridge School of Clinical Medicine, Department of Medicine, Cambridge, UK. lhb22@cam.ac.uk
authors.forename: Louise H
authors.initials: LH
authors.lastname: Boyle
authors.forename: Jane C
authors.initials: JC
authors.lastname: Goodall
authors.forename: J S Hill
authors.initials: JS
authors.lastname: Gaston
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016905:Gram-Negative Bacterial Infections / Q000150:complications / Q000276:immunology; D015796:HLA-B27 Antigen / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D010455:Peptides / Q000276:immunology; D025242:Spondylarthropathies / Q000209:etiology / Q000276:immunology*
chemical_list: D015796:HLA-B27 Antigen; D000949:Histocompatibility Antigens Class II; D010455:Peptides