FIGURE 1.

Effect of CD3/CD28 costimulation on the Δψ_m, mitochondrial mass, ROI levels, cytoplasmic and mitochondrial Ca²⁺ levels, and NO production. Normal human PBL were treated with CD3/CD28 Abs and assayed after incubation at 37°C for 20 min (0.33 h), 4 h, and 24 h Δψ_m was monitored by TMRM and DiOC₆; mitochondrial mass was measured by NAO; ROI production was assessed by HE; cytoplasmic and mitochondrial Ca²⁺ levels were assessed by Fluo-3 and Rhod-2; and NO production was monitored by DAF-FM fluorescence. Results were expressed as relative fluorescence (RF) values with respect to those of unstimulated cells normalized at 1.0. Data present mean ± SE of eight independent experiments. Values of p (*, <0.05; **, <0.01; ***, <0.001) above each column reflect comparison to untreated cells, whereas p values over brackets represent differences between the time points indicated.