Figure 2. Governing of stress myelopoiesis by Podxl.

A] Podxl^+/+ and Podxl^ΔHC mice were administered 5-FU (150 mg/kg). On the days indicated, peripheral blood cell populations were assayed. Left and center panels report on numbers of peripheral blood (PB) neutrophils and monocytes among Podxl^+/+ and Podxl^ΔHC mice (means +/− SE, n=4). The right panel reports on total white blood cell (WBC), neutrophil, monocyte and lymphocyte counts in PB from Podxl^+/+ and Podxl^ΔHC mice at d13 post 5-FU dosing (means +/− SE, n=4). B] Podxl deletion dysregulates G-CSF induced neutrophil and monocyte formation: Podxl^f/f and Podxl^ΔHC mice (n=4) were dosed on d1–5 with G-CSF (125μg/kg) or PBS. Levels of peripheral blood cells then were determined. Upper panels define neutrophil and monocyte numbers at d6 (means +/− SE). In the lower panel, overall levels of peripheral blood neutrophils, eosinophils, basophils, monocytes and lymphocytes are reported. C] Following G-CSF administration (125μg/kg, d1–5), bone marrow and splenic cells were prepared from Podxl^f/f and Podxl^ΔHC mice. HPCs were then prepared as lineage negative bone marrow populations (depleted using antibodies to CD5, CD11b, CD19, CD45R, Ly6G/C and Ter119) and were used in CFU assays (means +/− SE< n=3). Findings for CFU-GEMM are illustrated. For CFU-GM no significant effects of Podxl-KO were observed (data not shown) D] For granulomyeloid progenitors prepared from Podxl^f/f or Podxl^ΔHC mouse bone marrow (at steady-state) populations of FITC-anti-Gr-1 or FITC-anti-CD11b positive HPCs were assayed by flow cytometry. Here, granulomyeloid progenitors were prepared as CD11b, Gr-1, Ly6G positive populations. Data are mean frequencies of positive cells (means +/− SE, n=3).