Synergism between erythropoietin and interleukin-3 in the induction of
hematopoietic stem cell proliferation and erythroid burst colony formation
G Migliaccio, AR Migliaccio and JW Visser
Department of Hematology, Istituto Superiore Sanita, Rome.
The influence of recombinant erythropoietin (Ep) and interleukin-3 (IL- 3)
on the proliferation and differentiation of murine hematopoietic stem and
progenitor cells was investigated in serum-deprived cultures. The
differentiation of progenitor cells, purified by collecting blast cell
colonies from spleen cell cultures of 5-fluorouracil-treated mice, was
evaluated by scoring the number and type of colonies appearing after eight
days in semisolid culture. IL-3 induced the formation of both erythroid and
granulocyte-macrophage colonies in a concentration- dependent fashion, the
plateau being reached at 300 U/mL. However, concentrations of IL-3 alone
that had little or no effect (less than or equal to 10 U/mL) induced
maximal numbers of erythroid bursts in the presence of Ep (1.5 IU/mL). In
the presence of Ep alone, no colonies were seen. Proliferation of quiescent
hematopoietic stem cells, purified by cell sorting and evaluated by spleen
colony assay (CFU-S), was investigated by measuring the total cell number
and CFU-S content and the DNA histogram at 20 and 48 hours of liquid
culture. Almost no cells or CFU-S survived 20 hours of incubation without
the addition of IL-3. The presence of either IL-3 (400 U/mL) or the
combination of EP and IL-3 (10 U/mL), supported the maintenance of nearly
40% of sorted CFU-S for 48 hours. Approximately 10% of these cells were in
the S phase of the cell cycle at 20 hours and an increase in the total cell
number per culture, but not in the CFU-S content, was detected at 48 hours.
These data indicate that IL-3 exerts a differentiative and proliferative
effect on early stem and progenitor cells, which is concentration
dependent. At IL-3 concentrations, which had little or no activity alone,
Ep acted synergistically to induce both proliferation of stem cells and
differentiation of erythroid progenitors.
Volume 72,
Issue 3,
pp. 944-951,
09/01/1988
Copyright © 1988 by The American Society of Hematology
