Cell kinetics of GM-CFC in the steady state.
The kinetics of cell turnover for myeloid/monocyte cells that form colonies in agar (GM-CFC) were measured through the progressive increase in their sensitivity to 313-nm light during a period of cell labeling with BrdCyd. Two components of cell killing with distinctly separate labeling kinetics revealed both the presence of two generations within the GM-CFC compartment and the properties of the kinetics of the precursors of the GM-CFC. These precursors of the GM-CFC were not assayable in a routine GM-CFC assay when pregnant mouse uterus extract and mouse L-cell-conditioned medium were used to stimulate colony formation but were revealed by the labeling kinetics of the assayable GM-CFC. Further, these precursor cells appeared to enter the assayable GM-CFC population from a noncycling state. This was evidenced by the failure of the majority of these cells to incorporate BrdCyd during five days of infusion. The half-time for cell turnover within this precursor compartment was measured to be approximately 5.5 days. Further, these normally noncycling cells proliferated rapidly in response to endotoxin. High-proliferative-potential colony-forming cells (HPP-CFC) were tested as a candidate for this precursor population. The results of the determination of the kinetics for these cells showed that the HPP-CFC exist largely in a Go state, existing at an average rate of once every four days. The slow turnover time for these cells and their response to endotoxin challenge are consistent with a close relationship between the HPP-CFC and the Go pool of cells that is the direct precursor of the GM-CFC.
D000818:Animals; D001854:Bone Marrow Cells; D001972:Bromodeoxycytidine / Q000378:metabolism*; D002455:Cell Division; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003841:Deoxycytidine / Q000031:analogs & derivatives*; D004731:Endotoxins / Q000494:pharmacology; D005260:Female; D051379:Mice; D009000:Monocytes / Q000528:radiation effects; D014466:Ultraviolet Rays
D004731:Endotoxins; D003841:Deoxycytidine; D001972:Bromodeoxycytidine