Figure 3.

Extracellular superoxide production is not required for primary human T-cell activation. (A) Primary human T cells were stimulated with CD3xCD28-coated microbeads alone or in the presence of either SOD, catalase or ascorbate. After 16 hours cells were stained with CD25-FITC and CD69-PE mAbs and analyzed by flow cytometry. The data are representative of 3 independent experiments. (B) Quantification of (A). The values indicate the mean fluorescence intensities normalized to stimulated controls. (C) Quantification of (A). The values indicate the percentages of CD25⁺CD69⁺ cells normalized to stimulated controls.