Targeted C/EBPα deletion has no effect on late-stage DC development. (A) CD11c-Cre⁺ × C/EBPαfl/fl and C/EBPαfl/fl control mice were analyzed by flow cytometry between 8 and 12 weeks of age. Flow cytometry analysis of DC populations from the spleens of mice of the indicated genotypes are shown as dot plots. cDC are defined as CD19^–, CD3^–, NK^–, CD11c⁺, and MHCII⁺, whereas pDC were gated as CD19^–, CD3^–, NK^–, CD11c^lo, and B220⁺. Boxes are used to indicate the position of the DC populations in each group with the average percentage per spleen. FACS plots were taken from 3 similar experiments. (B) Histograms of flow cytometric analysis of CD11c⁺ splenic DC from CD11c-Cre⁺ C/EBPαfl/fl or C/EBPαfl/fl mice for subpopulations of DCs for CD4, CD8, CD11b, CD40, CD80, CD86, IL3Rα, and M-CSFR. Percentages are representative of similar experiments. (C) CD11c-Cre⁺ x C/EBPαfl/fl or C/EBPαfl/fl splenic DCs were sorted from 12-week-old mice. These cells were stimulated with LPS for 10 hours and then RT-PCR was performed for expression of cytokine transcripts. RT-PCR analysis displayed in a heatmap for transcripts from steady-state and LPS stimulated DC from both control and flox-deleted DCs. Data are shown from 2 similar experiments. (D) Control or C/EBPα-depleted DCs were sorted as CD11c⁺ CD19^–, and CD3^– into 72-hour cultures along with magnetic bead column–enriched CD3⁺ splenic cells to induce the proliferation of autologous T-lineage cells. The proliferative response of T-lineage cells was measured by tritiated thymidine incorporation after 16 hours. Results are representative of 2 experiments, and each value represents the mean from triplicate wells.