Myeloid differentiation in the humanized CSF-1 mice and cross-reactivity of human CSF-1. (A) Absolute numbers of BM cells of CSF1^m/m, CSF1^h/m, and CSF1^h/h mice, as average per animal (2 tibia and fibula), were determined. Each group contains n = 5 mice, age 4 weeks. Error bars indicate ± SEM. Data are representative of 3 independent experiments. (B) Single-cell suspension of BM (top), spleen (middle), and peripheral blood (PB) from CSF1^m/m, CSF1^h/m, and CSF1^h/h mice were prepared, stained with Gr1 and CD11b antibodies, and analyzed by flow cytometry. (C) Single-cell suspension of BM (top) and spleen (middle) from CSF1^m/m, CSF1^h/m, and CSF1^h/h mice were prepared, stained with F4/80 and CD11b antibodies, and analyzed by flow cytometry. (D) BM cells were isolated and cultured in the presence of either recombinant mouse CSF-1 (left) or human CSF-1 (right) for 7 days. Cells were stained with F4/80 and CD11b antibodies and analyzed by flow cytometry. (E) BM cells were isolated and cultured in the presence of either recombinant mouse CSF-1 (filled) or human CSF-1 (open) for 7 days. Cells were stained with indicated surface markers and analyzed by flow cytometry.