Fig. 5.

Secreted factors from pR-activated pDCs reduce the proliferation of stimulated T cells but increase their ability to produce IFN-γ. T cells were stimulated with overnight-activated mDCs and pDCs, cultured either alone or in 5:1 or 1:1 ratios, or with anti-CD3/anti-CD28 beads in the presence of indicated stimuli. The proliferative responses were investigated after 5 days by flow cytometry. Secretion of IFN-γ at day 4 was measured by ELISA. a Mean percentage ± SEM proliferating T cells induced by six DC donors. b Mean levels of secreted IFN-γ ± SEM from seven DC donors at day 4 of culture. c Mean percentage ± SEM proliferating anti-CD3/anti-CD28-activated T cells treated with medium alone, pR-CM, IL-3-CM, or freshly made pR complexes from six donors. d Mean percentage ± SEM proliferating T cells induced by three to seven mDC donors in the presence of medium alone, pR-CM, or IL-3-CM. e Mean percentage ± SEM proliferating T cells induced by six DC donors that were washed three times before addition of T cells. f Mean levels of secreted IFN-γ ± SEM at day 4 from seven washed DC donors. g Illustrative drawing of experimental set-up. Statistical differences were analyzed by paired one-way ANOVA or, for (d), ordinary ANOVA with Bonferroni’s multiple comparison test and significance is indicated by *(p < 0.05), **(p < 0.01), ***(p < 0.001), or ns (non-significant). All unlabeled comparisons in figures a, b, e, and f were statistically non-significant