In situ radiation sensitivity of recombinant human granulocyte colony- stimulating factor-recruited murine circulating blood and bone marrow progenitors (colony-forming unit [CFU]-granulocyte-macrophage and CFU- megakaryocyte): evidence for possible biologic differences between mobilized blood and bone marrow

摘要: Increasing evidence especially stemming from peripheral blood progenitor transplantation studies points to a possible biologic difference between mobilized and bone marrow cells. The objective of this study was compare the in situ radiation sensitivity recombinant human granulocyte colony-stimulating factor (rhG-CSF)-recruited circulating granulopoietic (blood colony-forming unit-granulocyte-macrophage [CFU-GM(blood)]) megakaryocytopoietic CFU-megakaryocyte [CFU-Meg(blood)]) progenitors, with nonmobilized fraction remaining (CFU-GM(femur) CFU-Meg(femur)). Splenectomized male B6D2F1 mice received 50 micrograms/kg/d rhG-CSF daily for 8 days induce high levels followed by either total body X-irradiation (TBI) or chest (CI) 62.5, 125, 250, 500 cGy. Progenitor cells were assayed 24 hours after irradiation. Circulating CFU-GM CFU-Meg decreased dose- dependent fashion both TBI CI, causing greater damage than CI. Average D0 values 53 cGy CFU-GM(blood) 40 CFU-Meg(blood) CI 90 140 CFU-Meg(blood). As seen cells, caused dose-dependent decrease CFU-GM(femur) (D0, 136 cGy) CFU-Meg(femur) 148 cGy). However, radiation-induced cell kill significantly lower when compared progenitors. Despite fact that elements only dose administered as Cl, extent Cl higher effects identical doses on CFU. results showed rhG-CSF-recruited considerably more radiosensitive femoral thereby providing novel rhG-CSF- recruited progenitors nonrecruited