PMID- 25861975 OWN - NLM STAT- MEDLINE DCOM- 20151230 LR - 20220409 IS - 1545-3278 (Electronic) IS - 0732-0582 (Linking) VI - 33 DP - 2015 TI - HLA-B27. PG - 29-48 LID - 10.1146/annurev-immunol-032414-112110 [doi] AB - Possession of the human leukocyte antigen (HLA) class I molecule B27 is strongly associated with ankylosing spondylitis (AS), but the pathogenic role of HLA-B27 is unknown. Two broad theories most likely explain the role of HLA-B27 in AS pathogenesis. The first is based on the natural immunological function of HLA-B27 of presenting antigenic peptides to cytotoxic T cells. Thus, HLA-B27-restricted immune responses to self-antigens, or arthritogenic peptides, might drive immunopathology. B27 can also "behave badly," misfolding during assembly and leading to endoplasmic reticulum stress and autophagy responses. beta2m-free B27 heavy chain structures including homodimers (B272) can also be expressed at the cell surface following endosomal recycling of cell surface heterotrimers. Cell surface free heavy chains and B272 bind to innate immune receptors on T, NK, and myeloid cells with proinflammatory effects. This review describes the natural function of HLA-B27, its disease associations, and the current theories as to its pathogenic role. FAU - Bowness, Paul AU - Bowness P AD - Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Science (NDORMS), Botnar Research Center, University of Oxford, Headington, Oxford OX3 9DL, United Kingdom; email: Paul.bowness@ndorms.ox.ac.uk. LA - eng PT - Journal Article PT - Review PL - United States TA - Annu Rev Immunol JT - Annual review of immunology JID - 8309206 RN - 0 (HLA-B27 Antigen) SB - IM MH - Animals MH - HLA-B27 Antigen/chemistry/genetics/*immunology/*metabolism MH - Humans MH - Spondylarthropathies/etiology OTO - NOTNLM OT - ankylosing spondylitis OT - antigen presentation OT - arthritogenic peptide OT - homodimer OT - spondyloarthritis EDAT- 2015/04/12 06:00 MHDA- 2015/12/31 06:00 CRDT- 2015/04/12 06:00 PHST- 2015/04/12 06:00 [entrez] PHST- 2015/04/12 06:00 [pubmed] PHST- 2015/12/31 06:00 [medline] AID - 10.1146/annurev-immunol-032414-112110 [doi] PST - ppublish SO - Annu Rev Immunol. 2015;33:29-48. doi: 10.1146/annurev-immunol-032414-112110.