mTOR deletion intrinsically impedes CD115 expression at the translation and transcription level. (A) GMPs sorted from tamoxifen-treated WT and ER-mTOR mice were cultured in the presence of M-CSF, IL-6+IL-3, or GM-CSF for 5 days in vitro and then collected for phenotype analysis by flow cytometry. The flow cytometry analysis of CD115 in induced cells is shown. The remarkable decreased percentages (B) and the cell numbers (C) of CD11b⁺CD115⁺ cells during the macrophage induction in vitro are shown. Results are representative of 3 independent experiments. (D) The mixed chimeric mice were generated as described in “Methods,” and the CD115⁺ cells in blood, bone marrow, spleen, and peritoneal cavity were detected. (E) The CD115⁺ cell compartment in blood, bone marrow, spleen, and peritoneal cavity of WT and ER-mTOR KO bone marrow cells was presented. Data are representative of 3 independent experiments. Data are mean ± SD (n = 5). (F) GMPs sorted from tamoxifen-treated WT and ER-mTOR mice were lysed for RNA extraction and analyzed for the transcriptional factor expression of CSF1R, CSF3R, CSF2rb, and SCF. Three mice in each group were assayed. **P < .01; ***P < .001 compared with WT control.