STAT5 mediates CD103⁺ DC development and pDC inhibition. Hematopoietic-Stat5^Δ/Δ and Stat5^+/+ animals were treated by HGT with GM-CSF–encoding plasmid (5 μg) or empty pORF vector, as indicated. The proportion and absolute number of specific DC subsets in BM, spleen, and liver were determined after 7 days by flow cytometry (A) and enumeration (B). DC populations were defined by the following criteria: PDCs, CD11c⁺ CD11b^- B220⁺; CD8α⁺ DCs, CD11c⁺ B220^- CD8α⁺; CD4⁺ DCs, CD11c⁺ B220^- CD4⁺; CD4^- CD8α^- DCs, CD11c⁺ B220^- CD4^- CD8α^-; CD103⁺ DCs, CD11c⁺ CD45⁺ B220^- MHC II⁺ CD103⁺. (A) Results indicate the percentage of each DC subset within the total BM, spleen, or liver population and represent data from 3 independent experiments. (B) Results indicate absolute numbers of each DC subset within BM (2 femurs, 2 tibiae), spleen, or liver. n = 3-6 mice/group. Error bars represent SEM of average values. P values of indicated comparisons are shown.