Immature splenic DCs become functionally mature during culture in vitro. (A) Purified CD8^– and CD8⁺ spleen DCs were incubated with OVA for 45 minutes, washed, and then incubated with CFSE-labeled OT-II cells immediately (0) or after 18 hours of culture. OT-II proliferation was assessed 3 days later. The results are representative of 4 experiments. (B) Spleen CD8^– and CD8⁺ DCs were incubated for 45 minutes with OVA immediately after purification (0) or after culture in vitro for 18 hours, washed, and then cultured for 3 days with CFSE-labeled OT-II cells. The results are representative of 3 experiments.