GA impairs the T cell activation capacity of stimulated MO-DC. Groups of MO-DCs were generated as described (see legend of Figure 2). (a) Titrated numbers of the various MO-DC populations (starting at 2 × 104 cells, two-fold diluted) were cocultured with allogenic CD4+ T cells (105) in triplicates for 4 days. T cell proliferation was assessed by uptake of [3H] thymidine during the last 16 h of culture. CD4+ T cell proliferation as induced by unstimulated or stimulated MO-DCs left untreated employed at the highest DC number was arbitrarily set to one in each experiment. Graphs show the means ± SEM of 3 independent experiments compiled. (b) Supernatants of day 4 DC/T cell cocultures (ratio 1:5) were assayed for cytokine contents by ELISA. Graphs show relative cytokine levels, normalized to the levels of unstimulated or stimulated MO-DCs left untreated. Data represent the means ± SEM of 7 independent experiments each. Statistical significance: (a) *GA-treated versus untreated MO-DCs; (b) *versus unstimulated untreated MO-DCs (*P < 0.05, **P < 0.01).