title: Expression of regulatory receptors on γδ T cells and their cytokine production in Behcet's disease.
abstract: BACKGROUND
  Behcet's disease (BD) is a multi-systemic disorder with muco-cutaneous, ocular, arthritic, vascular or central nervous system involvement. The role of γδ T cells is implicated in BD. The activation status of γδ T cells and their cytokine secretion against phosphoantigens are evaluated in BD.
  
  
  METHODS
  NKG2A, NKG2C, NKG2D, CD16 and CCR7 molecules on γδ T cells were analyzed in 70 BD, 27 tuberculosis (TB) patients and 26 healthy controls (HC). Peripheral γδ T cells were expanded with a phosphoantigen (BrHPP) and IL-2, restimulated with BrHPP and a TLR3 ligand, and cytokine production was measured.
  
  
  RESULTS
  γδ T cells were not increased in both BD and TB patients, but the proportions of TCRVδ2+ T cells were lower (58.9 and 50.7 vs. 71.7%, P=0.04 and P=0.005) compared to HC. Higher proportion of TCRVδ2+ T cells were CD16+ (26.2 and 33.9 vs. 16.6%, P=0.02 and P=0.001) and CCR7- (32.2 and 27.9 vs. 17.7%, P<0.0001 and P=0.014) in BD and TB patients compared to HC. NKG2C+ γδ+ T cells were relatively increased (0.5 and 0.6 vs. 0.3%, P=0.008 and 0.018), whereas NKG2D positivity was decreased in patients with BD and TB (77.7 and 75.8 vs. 87.5%, P=0.001 and 0.004). Expansion capacity of γδ T cells in BD and TB as well as production of IL-13, IFN-γ, granulocyte monocyte colony stimulating factor (GM-CSF), TNF-α, CCL4 and CCL5 in BD was lower compared to HC, when restimulated by TLR3 ligand and BrHPP.
  
  
  CONCLUSIONS
  The changes on γδ T cells of BD as well as TB patients implicate that γδ T cells have already been exposed to regulatory effects, which changed their activity. Lower cytokine response of γδ T cells implicates down modulation of these cells in BD.
authors: Gunes
authors: G
authors: Parlakgul
authors: Ekin
authors: E
authors: Guney
authors: Burak
authors: B
authors: Erer
authors: Zeki
authors: Z
authors: Kılıcaslan
authors: Haner
authors: H
authors: Direskeneli
authors: Ahmet
authors: A
authors: Gul
authors: Guher
authors: G
authors: Saruhan-Direskeneli
mesh_terms: D000328:Adult; D001528:Behcet Syndrome / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016207:Cytokines; D016692:Receptors, Antigen, T-Cell, gamma-delta