Oxidative stress is involved in PVR up-regulation on Ag-activated T cells. (A) CFSE-labeled PBMCs were activated with SEB. NAC (5mM) was added after 48 hours and left for an additional 18 hours. Cells were then stained as described in the legend to Figure 3A. The MFI of isotypic control mAb was subtracted from PVR MFI. Each of the 10 donors tested is represented by a different symbol. Statistical analysis was with the Student paired t test. (B) PBMCs were activated and treated as described in panel A and then stained as described in the legend to Figure 3B. The percentage of cells in each quadrant is displayed. The experiment shown is representative of the 6 performed.