Vγ9/Vδ2 T lymphocytes in Italian patients with Behçet's disease: evidence for expansion, and tumour necrosis factor receptor II and interleukin-12 receptor β1 expression in active disease
1 Department of Internal Medicine, Section of Rheumatology & Clinical Immunology, University of Palermo, Palermo, Italy
2 Department of BioPathology, Section of General Pathology, University of Palermo, Palermo, Italy
3 Department of Internal Medicine, Division of Internal Medicine, University of Palermo, Palermo, Italy
Arthritis Res Ther 2003, 5:R262-R268 doi:10.1186/ar785Published: 30 June 2003
Behçet's disease is a multisystem disease in which there is evidence of immunological dysregulation. It has been proposed that γ/δ T cells are involved in its pathogenesis. The aim of the present study was to assess the capacity of γ/δ T cells with phenotype Vγ9/Vδ2, from a group of Italian patients with Behçet's disease, to proliferate in the presence of various phosphoantigens and to express tumour necrosis factor (TNF) and IL-12 receptors. Twenty-five patients and 45 healthy individuals were studied. Vγ9/Vδ2 T cells were analyzed by fluorescence activated cell sorting, utilizing specific monoclonal antibodies. For the expansion of Vγ9/Vδ2 T cells, lymphocytes were cultured in the presence of various phosphoantigens. The expression of TNF receptor II and IL-12 receptor β1 was evaluated with the simultaneous use of anti-TNF receptor II phycoerythrin-labelled (PE) or anti-IL-12 receptor β1 PE and anti-Vδ2 T-cell receptor fluorescein isothiocyanate. There was a certain hierarchy in the response of Vγ9/Vδ2 T cells toward the different phosphoantigens, with the highest expansion factor obtained with dimethylallyl pyrophosphate and the lowest with xylose 1P. The expansion factor was fivefold greater in patients with active disease than in those with inactive disease or in control individuals. TNF receptor II and IL-12 receptor β1 expressions were increased in both patients and control individuals. The proportion of Vγ9/Vδ2 T cells bearing these receptors was raised in active disease when Vγ9/Vδ2 T cells were cultured in the presence of dimethylallyl pyrophosphate. These results indicate that Vγ9/Vδ2 T cell activation is correlated with disease progression and probably involved in the pathogenesis.