title: Prevalence, clinical relevance and characterization of circulating cytotoxic CD4+CD28- T cells in ankylosing spondylitis.
abstract: Circulating CD3+CD4+CD28- cells exhibit reduced apoptosis and were found to be more enriched in patients with ankylosing spondylitis than in age-matched healthy control individuals (7.40 +/- 6.6% versus 1.03 +/- 1.0%; P < 0.001). Levels of CD4+CD28- T cells correlate with disease status as measured using a modified metrology score, but they are independent of age and duration of ankylosing spondylitis. CD4+CD28- T cells produce IFN-gamma and perforin, and thus they must be considered proinflammatory and cytotoxic. These T cells share phenotypic and functional properties of natural killer cells, strongly expressing CD57 but lacking the lymphocyte marker CD7. MHC class I recognizing and activating natural killer cell receptors on the surface of CD4+CD28- T cells may be involved in a HLA-B27 mediated co-stimulation of these proinflammatory and cytotoxic cells.
authors.affiliation: Department of Internal Medicine, University of Innsbruck, Innsbruck, Austria.
authors.forename: Christina
authors.initials: C
authors.lastname: Duftner
authors.forename: Christian
authors.initials: C
authors.lastname: Goldberger
authors.forename: Albrecht
authors.initials: A
authors.lastname: Falkenbach
authors.forename: Reinhard
authors.initials: R
authors.lastname: Würzner
authors.forename: Barbara
authors.initials: B
authors.lastname: Falkensammer
authors.forename: Karl P
authors.initials: KP
authors.lastname: Pfeiffer
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Maerker-Hermann
authors.forename: Michael
authors.initials: M
authors.lastname: Schirmer
mesh_terms: D017209:Apoptosis / Q000502:physiology; D018106:CD28 Antigens / Q000096:biosynthesis / Q000378:metabolism*; D015704:CD4 Antigens / Q000096:biosynthesis / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D015796:HLA-B27 Antigen / Q000502:physiology; D006801:Humans; D007694:Killer Cells, Natural / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D007963:Leukocytes, Mononuclear / Q000473:pathology; D008875:Middle Aged; D015995:Prevalence; D013167:Spondylitis, Ankylosing / Q000097:blood* / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000737:chemistry* / Q000473:pathology / Q000502:physiology*; D013602:T-Lymphocytes, Cytotoxic / Q000737:chemistry* / Q000473:pathology / Q000502:physiology*; D014162:Transfection
chemical_list: D018106:CD28 Antigens; D015704:CD4 Antigens; D015796:HLA-B27 Antigen