Improved survival and marrow engraftment of mice transplanted with bone marrow of GM‐CSF‐treated donors

Abstract: Recombinant granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) administered to bone marrow (BM) transplant recipients is associated with earlier recovery. We have investigated the possibility of stimulating normal donor mice in vivo with GM‐CSF. Donor balb/c mice were injected i.p. with GM‐CSF (5000 u) or saline. Seventy‐two hours later 5 × 10⁵ BM cells from either GM‐CSF‐treated or control donors were infused into lethally irradiated (850 R) recipients. In the recipients of BM from GM‐CSF‐treated donors, significantly higher CFU‐S and significantly higher survival rate (57% [n = 65]; vs. 30% [n = 63]; p<0.05) were noted. Donor mice of the GM‐CSF group did not differ in bone‐marrow cellularity and composition from their controls. However, recipients of BM from GM‐CSF‐treated mice had higher blood counts of haemoglobin, leukocytes and platelets compared to controls. These data demonstrate that pretreatment of BM donors with GM‐CSF may be of benefit in improving survival and marrow engraftment in mice.