title: Ankylosing spondylitis patients display altered dendritic cell and T cell populations that implicate pathogenic roles for the IL-23 cytokine axis and intestinal inflammation.
abstract: OBJECTIVE
  AS is a systemic inflammatory disease of the SpA family. Polymorphisms at loci including HLA-B27, IL-23R and ERAP-1 directly implicate immune mechanisms in AS pathogenesis. Previously, in an SpA model, we identified HLA-B27-mediated effects on dendritic cells that promoted disease-associated Th17 cells. Here we extend these studies to AS patients using deep immunophenotyping of candidate pathogenic cell populations. The aim of our study was to functionally characterize the immune populations mediating AS pathology.
  
  
  METHODS
  Using 11-parameter flow cytometry, we characterized the phenotype and functions of lymphocyte and myeloid cells from peripheral blood, and the synovial phenotype of AS patients and age-matched healthy controls.
  
  
  RESULTS
  Significantly fewer circulating CD1c-expressing dendritic cells were observed in AS patients, offset by an increase in CD14(-) CD16(+) mononuclear cells. Ex vivo functional analysis revealed that this latter population induced CCR6 expression and promoted secretion of IL-1β and IL-6 when co-cultured with naive CD4(+) T cells. Additionally, systemic inflammation in AS patients significantly correlated with increased proportions of activated CCR9(+) CD4(+) T cells.
  
  
  CONCLUSIONS
  CD14(-) CD16(+) mononuclear cells may contribute to AS by promoting Th17 responses, and antigen-presenting cells of mucosal origin are likely to contribute to systemic inflammation in AS.
authors: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow and.
authors: Pamela B
authors: PB
authors: Wright
authors: Department of Rheumatology, Queen Elizabeth Building, Glasgow Royal Infirmary, Glasgow, UK.
authors: Anne
authors: A
authors: McEntegart
authors: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow and.
authors: David
authors: D
authors: McCarey
authors: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow and.
authors: Iain B
authors: IB
authors: McInnes
authors: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow and.
authors: Stefan
authors: S
authors: Siebert
authors: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow and simon.milling@glasgow.ac.uk.
authors: Simon W F
authors: SW
authors: Milling
mesh_terms: D000328:Adult; D000818:Animals; D004247:DNA / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007111:Immunity, Cellular; D007249:Inflammation / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D053759:Interleukin-23 / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D013167:Spondylitis, Ankylosing / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D053759:Interleukin-23; D004247:DNA
keywords: CD14− CD16+ mononuclear cells; CD4+ T cells; ankylosing spondylitis; dendritic cells; inflammation