Cells were labeled with the following of monoclonal antibodies purchased from eBioscience or Biolegend at the listed concentrations for 20–30 minutes, unless otherwise noted. CMP were isolated as described (4 (link)). Briefly, whole bone marrow was isolated and depleted of lineage positive cells by MACS lineage depletion kit (Miltenyi). Lineage negative cells were blocked with fluorescently-labeled anti-CD16/32 (93; 1:100), then incubated with biotinylated mAbs to CD45 (30-F11; 1:100), CD3 (17A2; 1:100), CD11b (M1/70; 1:600), CD11c (N418; 1:100), NK1.1 (PK136; 1:100), F4/80 (BM8; 1:100), B220 (RA3-6B2; 1:100), Gr1 (RB6-8C5; 1:600), Ter119 (Ter-119; 1:100) and CD127 (A7R34; 1:100). The cells were then washed and stained with mAbs to CD34 (RAM34; 1:10), Sca1 (D7; 1:100), CD117 (ACK2; 1:100) and SA-APCe780 for 60–90 minutes. For assessment of intracellular signaling pathways, the following antibodies from Cell Signaling Technologies were used: phosphorylated S6 (D572.2E; 1:200), IkBα (L35A5; 1:100) and phosphorylated STAT1 (58D6; 1:10). Data were acquired on a LSRII or FACSCanto (BD Biosciences) or cells sorted on a FACSAria and analyzed using FlowJo (TreeStar).