Figure 5. Purinergic signalling modulates Tc1 responses.

(a) CD39⁺CD8⁺ or CD39⁻CD8⁺ T cells were used after purification (fresh) or after activation using anti-CD3/CD28 antibodies for 3 h (activated). Phosphohydrolysis of extracellular ¹⁴C-radiolabelled ADP catalysed by fresh or activated CD39⁺CD8⁺ or CD39⁻CD8⁺ T-cell subsets was determined by TLC. (b,c) Total CD8⁺ T cells (b) or freshly sorted CD39⁻CD8⁺ T cells (c) were stimulated with anti-CD3/CD28 antibodies in the presence of vehicle or CGS21680 (100 nM), adenosine (ADO, 50 μM) alone or together with CSC (500 nM) or XAC (1 μM) for 24 h, IFNγ expression was analysed by fluorescence-activated cell sorting (FACS). (d) Carboxyfluorescein succinimidyl ester-labelled CD39⁻CD8⁺ T cells alone or co-cultured with CD4⁺CD39⁺CD161⁺ T cells were stimulated with anti-CD3/CD28 antibodies for 24 h followed by FACS analysis of IFNγ expression. Co-cultures were incubated in the presence of vehicle, CSC (500 nM) or XAC (1 μM). Data are representative of three independent experiments.