Both CD1a- or CD14-derived DC-induced T-cell priming are inhibited by anti-CD86 or IL-10. CD1a- and CD14-derived DC subsets were obtained as described in Materials and Methods and in the legend to Fig 1. At day 14, cells were used after irradiation (30 Gy) as stimulator cells (10³ cells/well) for cord blood CD4⁺ T cells (2 × 10⁴ cells/well). (A) Experiments were performed in the presence of 10 μg/mL of anti-CD80 (Mab 104), anti-CD86 (IT2-2), anti-CD80 plus anti-CD86, or isotype match control. (B) Experiments were performed in the presence or absence of IL-10 (50 ng/mL). Proliferation was shown by ³H-TdR uptake after 5 days of culture. Results are expressed as mean cpm ± SD of triplicate cultures. Results of each panel are representative of three experiments.