Figure 2.

C/EBPα is needed for FMS-related tyrosine kinase-3 ligand (FLT3L)-induced DC development. (A) FLT3L-induced in vitro formation of mature CD11c⁺MHCII⁺ DC is significantly reduced in Cebpa KO, as compared to WT hematopoietic stem and progenitor cells (HSPCs) (p < 0.01, n = 5 mice per group). Results are representative from three independent experiments. A representative flow cytometry plot for the analysis of mature CD11c⁺MHCII⁺ DC is shown on the left side (upper panel: WT, lower panel: KO). (B) Despite higher numbers of FLT3⁺CD117⁺ progenitors at day 0 (lower left panel), analysis of early differentiation after FLT3L treatment in vitro reveals a reduced formation of monocytic dendritic cell progenitors (MDPs) and a block of transition towards common dendritic cell progenitors (CDPs) in KO HSPCs. Cells were analyzed by flow cytometry on days 0, 1, and 3 of culture (upper panels: WT, lower panels: KO). The percentage of MDPs and CDPs of total CD117⁺ HSPCs on days 1 and 3 are given in the right lower panel. All data represent mean + SD of 5 mice (* p < 0.01, ** p < 0.001).