Fig. 2.

Hypoxia strongly suppressed T-cell proliferation as compared with the effect of A2AR stimulation by CGS. Proliferation of CFSE-labeled CD4⁺ and CD8⁺ cells after 36h was monitored separately for WT (A) and A2AR^−/− (B) T cells. Peaks with diminished fluorescence intensity (shown by numbers) indicate dilution of CFSE in proliferated cells. Results for normoxic culture, hypoxic culture and CGS (10⁻⁵ M) treatment shown here are representative of four separate experiments with similar results. (C) Proliferation index calculated as in Methods. The index represents average times of cell division in cells that divided at least once. Therefore, the minimum number of proliferation index is one. WT, WT mice; A2A, A2AR^−/− mice; N, normoxic atmosphere (21% oxygen); H, hypoxic atmosphere (1% oxygen); C, CGS (10⁻⁵ M); CH, CGS + 1% oxygen. Data represent average ± SD of triplicate samples. a, P < 0.05; c, P < 0.001 versus normoxia.