STAT3-independent development of pDCs by IFN-α. (A) Proportion of pDCs (top left quadrant) and cDCs (bottom right quadrant) in total BM cultures (10⁵ cells) from Tie2cre⁺Stat3^f/Δ mice or littermate control (Stat3^+/+) samples, after 4 days in GM-CSF or GM-CSF + IFN-α. Results were gated on the CD11c⁺ population (not shown); B220 and CD11b analysis is shown. Data represent 3 independent experiments. (B) Absolute number of pDCs and cDCs in total BM cultures shown in panel A. Error bars represent SEM of 3 independent experiments. (C) Proportion of pDCs and cDCs in BM and spleen of Tie2cre⁺Stat3^f/Δ mice and Stat3^+/+ mice, as indicated. Results were analyzed as indicated in panel A. Data represent 3 independent experiments. (D) Absolute number of pDCs and cDCs in BM and spleen of Tie2cre⁺Stat3^f/Δ mice and Stat3^+/+ mice, as indicated. Data are the mean ± SEM from 4-8 mice. (E) Absolute number of DC progenitors (lin⁻ Flt3⁺ cells) in Tie2cre⁺Stat3^f/Δ mice and Stat3^+/+ mice, as indicated. Data are the mean ± SEM from 4-8 mice. (F) CpGA-induced IFN-α production from pDCs sorted from BM of Tie2cre⁺Stat3^f/Δ mice before or after IFN-α treatment. Error bars represent SEM of 4 to 8 individual samples.