Fig. 4.
Bay11 reduces CD8 T cell effector cytokine production by enhancing AICD. (A) Day 3 spleen cells were stimulated for 5 h with 1 μg SIINFEKL peptide (top panel), 125 ng/ml PMA plus 2.5 μg/ml ionomycin (middle panel), or nothing (bottom panel) in the presence of vehicle alone or Bay11 (0.5 μM, 5 μM, or 10 μM) and then assayed for intracellular cytokine production. Representative zebra plots are shown from each group of gated OT-I CD8 T cells. The numbers in the upper right quadrant indicate the percentage of OT-I CD8 T cells producing IFN-γ and TNF. This experiment was repeated at least three times, and the data are summarized in Table 2. (B) Day 4 dual-costimulated OT-I CD8 T cells (1×105 cells) were cultured for 4 h with media alone (left panel), 5 μg/ml SIINFEKL peptide (middle panel), or SIINFEKL peptide plus 10 μM Bay11 (right panel). All cells were assayed for mitochondrial membrane potential, and histograms show representative Mito Flow staining of total cells. Comparable data were obtained from at least three other experiments.