CD70TG mice have increased numbers of monocytes and increased monopoiesis over granulopoiesis. (A) Representative plots of staining for monocytes (Gr1^lowCD115⁺) and neutrophils (Gr1⁺CD115⁻) within the CD11b⁺ compartment in the peripheral blood of WT and CD70TG mice and absolute numbers of monocytes and neutrophils in the peripheral blood (B) and BM (C) of WT and CD70TG mice. Data in panels B and C represent means ± SD from at least 3 mice per group. (D-E) Percentage of BrdU⁺ monocytes within the CD11b⁺ compartment in the peripheral blood of WT and CD70TG mice measured 12, 18, and 24 hours after injection of BrdU (D) and percentage of BrdU⁺ neutrophils in the peripheral blood of WT and CD70TG mice measured at indicated days after BrdU injection (E). Data in panels D and E represent means ± SEM from 5 mice per group. (F) Type of colonies derived from total BM from WT and CD70TG mice cultured for 8 days in semisolid medium. Data are displayed as the absolute number of CFUs per 25 000 BM cells (left) or as percentage from total colonies (right). M indicates monocyte/macrophage; G, granulocyte; and GM, mixed monocyte/macrophage and granulocyte. Data represent means ± SD from 6 mice per group. M:N ratios in BM (G) and peripheral blood (H) of WT and CD70TG mice were measured by dividing the number of monocytes by the number of neutrophils. Data in panels G and H represent means ± SD from at least 3 mice per group. BM represents cell numbers per 2 femurs and 2 tibiae. All experiments were performed at least 2 times with similar results. *P < .05; **P < .01; ***P < .001.