Detection of the target progenitor cells of granulomonopoietic enhancing
activity
SY Wang, YM Li, LY Chen, RC Wang, CK Lin and CK Ho
Department of Medical Research, Veterans General Hospital, Taiwan, Republic
of China.
Macrophage-derived granulomonopoietic enhancing activity (GM-EA) is a novel
mediator that amplifies colony formation of myeloid progenitor cells
(CFU-GM) in conjunction with colony-stimulating factors (CSFs), and is
distinct from other hematopoietic synergizing factors such as interleukin
(IL)-1, IL-4, and IL-6. In the present study, we try to ascertain whether
or not there is a GM-EA-specific responsive myeloid progenitor cell
population. Human bone marrow cells deleted of adherent cells and T
lymphocytes were separated by velocity sedimentation into three
subpopulations with respective sedimentation rates (millimeters per hour)
of 7.4 +/- 0.4, 6.0 +/- 0.6, and 4.7 +/- 0.3. These subpopulations
corresponded to the day 7 CFU-GM, day 14 CFU-GM, and the earlier myeloid
progenitor cells, pre-CFU-GM, respectively. Pre-CFU-GM failed to respond to
the colony-inducing effect of GM-CSF but could be stimulated by GM-EA alone
to generate small clusters (5 to 25 cells) in soft agar after 14 days of
incubation. Correspondingly, suspension preculture of the fractionated bone
marrow cells also showed that only the progenitor cells with low
sedimentation rate (4.7 mm/h) could be activated by GM-EA to generate
CFU-GM. Taken together, our results suggest that the specific target cell
of GM-EA is the pre-CFU-GM, and that GM-EA acts on these cells as a
growth/maturation factor, but on the day 7 and day 14 CFU-GM as a
synergistic growth factor.
Volume 76,
Issue 3,
pp. 495-500,
08/01/1990
Copyright © 1990 by The American Society of Hematology
