Open Access Research article

Expression of regulatory receptors on γδ T Cells and their cytokine production in Behcet's disease

Gunes Parlakgul1, Ekin Guney1, Burak Erer2, Zeki Kılıcaslan3, Haner Direskeneli4, Ahmet Gul2 and Guher Saruhan-Direskeneli5*

Author Affiliations

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

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Arthritis Research & Therapy 2013, 15:R15  doi:10.1186/ar4147

Published: 21 January 2013

Abstract

Introduction

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.

Conclusion

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.