Both granulocyte-macrophage CSF and macrophage CSF control the proliferation and survival of the same subset of alveolar macrophages.
The effect of granulocyte-macrophage (GM)-CSF on the proliferation of murine pulmonary alveolar macrophages in vitro was investigated. About 20% of freshly isolated alveolar macrophages formed colonies in both liquid and soft agar cultures in the presence of GM-CSF. GM-CSF was also found to be capable of maintaining the survival of these colony-forming cells in vitro. Moreover, GM-CSF could substitute for CSF-1 in maintaining the survival of CSF-1-responding pulmonary alveolar macrophage colony-forming cells in the absence of CSF-1. The concentration of GM-CSF required for maintaining the survival of colony-forming cells without proliferation was much lower than that required for the proliferation of these cells in vitro. It also enhanced the CSF-1-dependent clonal growth of alveolar macrophages. These data suggest that the colony-forming cells that respond to GM-CSF are the same subset of macrophages that form colonies in the presence of CSF-1. GM-CSF did not inhibit the binding of 125I-CSF-1 to alveolar macrophages at 0 degrees C. However, the preincubation of macrophages with GM-CSF at 37 degrees C resulted in a transient down-regulation of CSF-1 binding activity.
Lin
H S
HS
Division of Radiation Oncology, Mallinckrodt Institute of Radiology, St. Louis, MO 63110.
Lokeshwar
B L
BL
Hsu
S
S
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000378:metabolism / Q000502:physiology*; D004357:Drug Synergism; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006098:Granulocytes / Q000502:physiology*; D006133:Growth Substances / Q000378:metabolism / Q000502:physiology*; D008264:Macrophages / Q000145:classification / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008809:Mice, Inbred C3H; D011650:Pulmonary Alveoli
D003115:Colony-Stimulating Factors; D006133:Growth Substances; D016178:Granulocyte-Macrophage Colony-Stimulating Factor