Expression of regulatory receptors on γδ T Cells and their cytokine production in Behcet's disease
- Equal contributors
1 Istanbul Medical Faculty, Istanbul University, Millet Caddesi, Çapa, Istanbul, 34093 Turkey
2 Division of Rheumatology, Department of Internal Medicine, Istanbul Medical Faculty, Istanbul University, Millet Caddesi, Çapa, Istanbul, 34093 Turkey
3 Department of Pulmonary Diseases, Istanbul Medical Faculty, Istanbul University, Millet Caddesi, Çapa, Istanbul, 34093 Turkey
4 Division of Rheumatology, Department of Internal Medicine, Marmara University, School of Medicine Hospital, Fevzi Çakmak Mahallesi, Mimar Sinan Caddesi, No: 41, Pendik, Istanbul, 34890 Turkey
5 Department of Physiology, Istanbul Medical Faculty, Istanbul University, Millet Caddesi, Çapa, Istanbul, 34093 Turkey
Arthritis Research & Therapy 2013, 15:R15 doi:10.1186/ar4147Published: 21 January 2013
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.
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.
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.
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.