Publication
Title
Transforming growth factor-ß regulates the cell cycle status of interleukin-3 plus interleukin-1, stem cell factor or interleukin-6 stimulated $CD34^{+}$ human hematopoietic progenitor cells through different cell kinetic mechanisms depending on the applied stimulus
Author
Abstract
 The immediate cell kinetic response of highly purified human bone marrow progenitor cells (CD34(+) sorted fraction) to the inhibitory effects of transforming growth factor-beta (TGF-beta) was studied using the BrdU-Hoechst flow-cytometric technique. The progenitor cells were stimulated with either interleukin-3 (IL-3) alone or with IL-3 in combination with IL-1, stem cell factor (SCF), or IL-6, and the inhibitory action of TGF-beta was evaluated in each phase of the first three consecutive tell cycles. Semisolid methylcellulose cultures were also performed to compare these initial events to the effects observed after 7, 14, and 21 days of incubation. Within the CD34(+) compartment, the progenitor cells can be discriminated on a functional basis, i.e., in terms of TGF-beta sensitivity. Very primitive progenitors, recruited out of the G(0) phase by IL-3 plus an early-acting factor (IL-1, SCF) are, upon addition of TGF-beta, arrested specifically in the G(1) phase of the second cell cycle. In the clonogenic assays, the increased colony formation due to IL-1 or SCF was completely abolished by the counteracting effect of TGF-beta that diminished colony output back to the level of TGF-beta-plus-IL-3 supplemented colony growth. Addition of TGF-beta to CD34(+) progenitors responding to IL-3 alone resulted in an overall retardation, but without an apparent specific accumulation of cells in any of the cell cycles. Finally, within the CD34(+) compartment, there exists a subset of IL-3-responsive, but TGF-beta-insensitive, progenitor cells that were, upon addition of TGF-beta, not arrested at all. In conclusion, our results demonstrate that TGF-beta exerts different cell kinetic effects on CD34(+) progenitor cell growth depending on the applied stimulus.
Language
English
Source (journal)
Experimental hematology. - Oak Ridge, Tenn., 1973, currens
Publication
Oak Ridge, Tenn. : 1994
ISSN
0301-472X
1873-2399 [online]
Volume/pages
22:9(1994), p. 903-909
ISI
A1994PB17700008
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address