Decreased CDPs and CD8⁻ cDCs in p15Ink4b^fl/flLysMcre mice. (A) Flow cytometry and gating strategy of lineage-negative enriched mouse progenitors to identify Flt3⁺M-CSFR⁺ CDPs and Flt3⁻M-CSFR⁻ multipotent progenitors. Percentages (B) and total cell numbers (C) of CDPs and multipotent progenitors (MPPs) in p15Ink4b^wt/wt-LysMcre mice (wt/wt, n = 6) and p15Ink4b^fl/fl-LysMcre mice (fl/fl, n = 6). (D) Percentages of CDPs and multipotent progenitors in wild-type (wt/wt) and embryonal p15Ink4b knockout (ko/ko) mice. Data are shown as means ± SD. (E) Cell-cycle distribution of CDPs isolated from p15Ink4b^wt/wt-LysMcre mice (wt/wt) and p15Ink4b^fl/fl-LysMcre mice (fl/fl) mice. Frequency of CD8⁻ cDCs (defined here as CD11c⁺CD8⁻CD11b⁺) CD8⁺ cDCs (CD11c⁺CD8⁺CD11b⁻) and pDCs (CD11c⁺B220⁺CD11b⁻) in the spleen (F) and BM (G) of p15Ink4b^wt/wt-LysMcre (wt/wt, n = 9) and p15Ink4b^fl/fl-LysMcre (fl/fl, n = 9) mice. 2 × 10⁶ events were acquired for each sample. (H) Efficiency of LysMcre-driven deletion of p15Ink4b in FACS-sorted CD8⁻ cDCs, CD8⁺ cDCs, and pDCs isolated from p15Ink4b^wt/wt-LysMcre and p15Ink4b^fl/fl-LysMcre mice. DNA was analyzed by qPCR for the p15Ink4b exon2 copy number with p15Ink4b exon 1 used as an internal control. (I) Expression of MHC I, MHC II, CD80, and CD86 molecules on steady-state cDCs from spleen (Sp) and BM of p15Ink4b^wt/wt-LysMcre (black line) and p15Ink4b^fl/fl-LysMcre mice (red line). The results are representative histograms of 4 independent experiments with similar results. *P < .05; **P < .01; n.s. indicates not significant.