Stem cell factor and interleukin-7 synergize to enhance early myelopoiesis
in vitro
C Fahlman, HK Blomhoff, OP Veiby, IK McNiece and SE Jacobsen
Department of Immunology, Norwegian Radiumhospital, Oslo.
Interleukin-7 (IL-7) has been shown to be a critical factor in murine
lymphoid development. It stimulates pre-B cells to divide in the absence of
stroma cells and it is an important growth regulator of immature and mature
T cells. IL-7 has been shown to synergize with stem cell factor (SCF) to
provide a potent growth stimulus for pre-B cells. However, the combined
effects of IL-7 and SCF on murine primitive hematopoietic cells in vitro
have not been established. In the present study, the effects of recombinant
rat (rr) SCF and recombinant human (rh) IL-7 on primitive murine bone
marrow progenitors (Lin-Sca1+) were investigated in single-cell cloning
experiments. rhIL-7 alone had no proliferative effect on Lin-Sca1+ cells,
but in a dose-dependent manner directly enhanced rrSCF-induced colony
formation, with an average increase in colony numbers of 2.7-fold.
Interestingly, the cells formed in response to SCF and IL-7 were
predominantly mature granulocytes. Thus, SCF and IL-7 synergize to
stimulate early myelopoiesis in vitro.
Volume 84,
Issue 5,
pp. 1450-1456,
09/01/1994
Copyright © 1994 by The American Society of Hematology
