Synergistic effects of granulocyte-colony stimulating factor and macrophage-colony stimulating factor on recovery of donor hematopoietic cells in allogeneic bone marrow transplantation.

G-CSF and M-CSF are used clinically to augment hematopoiesis after bone marrow transplantation (BMT) and chemotherapy. In this paper, we examined the synergistic effect of G-CSF and M-CSF on hematopoietic recovery in allogeneic BMT as a model of human BMT. We performed BMT from eGFP-transgenic mice (C57BL/6 background; H-2b) into lethally-irradiated C3H (H-2k). From the day after BMT, G-CSF and/or M-CSF were injected for 5 consecutive days. Not only the numbers of day 12 CFU-S and spleen weight, but also white blood cell (WBC) counts in the peripheral blood (PB) and nuclear cells in the bone marrow (BM) increased in the mice treated with G-CSF and/or M-CSF 12 days after BMT. Moreover, the number of donor-type WBCs in the PB and donor-type nuclear cells in the BM also increased in the mice treated with G-CSF and/or M-CSF. The effects were pronounced when G-CSF and M-CSF were used together rather than independently. These results suggest that treatment with the combination of G-CSF and M-CSF has a synergistic effect on hematopoiesis in allogeneic BMT.