Age-associated TNF inflammation increases myeloid progenitor differentiation in female mice 8 weeks after BMT with WT and Tet2^–/– HSPCs. (A) Experimental design and representative flow cytometric data showing CD45⁺ T-cell–depleted (TCD) BM donor cells transplanted in mice conditioned with busulfan. Young (6 months) and old (18-22 months) C57Bl/6-J WT and old TNF^–/– animals received 80 mg/kg busulfan and received transplantation with 2 × 10⁶ TCD-BM cells from young CD45.1⁺ WT and CD45.2⁺Tet2^–/– mice. (B) Histogram showing percentage of CD45.1⁺ WT and CD45.2 Tet2^–/– donor cells transplanted into recipient mice. (C) Ratio of CD45.2⁺Tet2^–/– to CD45.1⁺ WT leukocytes in the BM of recipient mice 8 weeks after BMT. (D-I) Flow cytometric analyses showing absolute counts of HSPC (D), common myeloid progenitor (CMP) cells (E), monocyte-dendritic progenitor (MDP) cells (F), granulocyte-monocyte progenitor (GMP) cells (G), common monocyte progenitor (cMoP) cells (H), and mature monocytes (I). (J) Absolute count of Ly6C^high inflammatory monocytes. (K) Geometric mean of CX₃ chemokine receptor 1 (CX3CR1) in BM monocytes. (L) Absolute counts of circulatory Ly6C^high monocytes. Statistical significance determined by 1-way analysis of variance (ANOVA). ∗P ≤ .05; ∗∗P ≤ .01; ∗∗∗P ≤ .001; ∗∗∗∗P ≤ .0001. ELISA, enzyme-linked immunosorbent assay; MFI, geometric mean fluorescence intensity.