title: Effects of GM-CSF deprivation on precursors of granulocytes and macrophages.
abstract: Culture of C57BL bone marrow cells in the absence of GM-CSF led to a loss of recoverable granulocyte-macrophage colony-forming cells of 2% per hour. The rate of loss of progenitor cells in cultures of CBA fetal liver cells was 5-6% per hour. Surviving colony-forming cells exhibited a normal responsiveness to GM-CSF but generated smaller colonies than normal when subsequently stimulated by GM-CSF. Transfer of washed individual day-3 granulocyte-macrophage colony cells to cultures lacking GM-CSF indicated that most cells were unable to survive or proliferate in the absence of GM-CSF. Death of transferred cells was rapid and invariable when the cells were from macrophage-forming colonies. However some cells from 40-70% of granulocyte-forming colonies were able to undergo one or two divisions in the absence of GM-CSF. This phenomenon was seen most often with cells from colonies where matching colony cells exhibited a higher-than-average proliferative capacity in parallel stimulated cultures. The results indicate the difficulty that will be encountered in obtaining valid metabolic data from unstimulated populations of granulocyte-macrophage precursor cells. The ability of some granulocyte precursor cells to exhibit limited proliferation following GM-CSF deprivation suggests that significant amounts of GM-CSF may be bound to or be internalized in some precursor cells and result in cell division in the absence of GM-CSF from culture medium.
mesh_terms: D000818:Animals; D001853:Bone Marrow; D002452:Cell Count / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002999:Clone Cells / Q000166:cytology; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D005260:Female; D006098:Granulocytes / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D008099:Liver; D008264:Macrophages / Q000166:cytology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA
chemical_list: D003115:Colony-Stimulating Factors