In vitro generation of Dll4^hiDCs. Flt3L-DCs were generated by incubating BALB/c mouse BM mononuclear cells in cultures with Flt3L. GM-DCs were induced by culturing c-kit⁺ hematopoietic progenitor cells in the presence of GM colony-stimulating factor, IL-4, and stem cell factor. After 8 days in culture, cells were collected and cultured in medium containing indicated stimuli for additional 24 hours. (A) Graphs show the number of CD11c⁺ cells (mean ± standard deviation [SD] of triplicates). (B) Histograms and a graph show the percentage of Dll4 on the surface of Flt3L-DCs (mean ± SD of triplicates). (C, E) Real-time reverse transcription polymerase chain reaction analysis revealed the relative expression of indicated genes in DCs generated in cultures (mean ± SD of triplicates). (D) Histograms show the expression of tested markers on the surface of DCs with or without stimulation of LPS+R848. Representative results of 3 independent experiments are shown. ** P < .01; *** P < .001.