Combined and sequential effects of human IL-3 and GM-CSF on the proliferation of CD34+ hematopoietic cells from cord blood

Abstract

The proliferative effects of recombinant human interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) were investigated in semi-solid and liquid cultures of purified CD34+ hematopoietic cells obtained from umbilical cord blood. No important differences in overall cloning efficiencies in response to IL-3 or GM- CSF were observed in semi-solid medium in the presence of erythropoietin (Ep). However, GM-CSF was less effective for the development of erythroid bursts (BFU-E), and only IL-3 was observed to induce significant numbers of mixed-erythroid colonies (E-MIX). Both IL- 3 and GM-CSF also induced proliferation of CD34+ in liquid cultures. Proliferative responses to IL-3 were found to be more rapid and stronger than to GM-CSF, although the number of initial responsive cells as judged by autoradiography were comparable. Enhanced proliferation of CD34+ cells both in semi-solid and liquid cultures was obtained in the presence of combinations of IL-3 and GM-CSF. The responses observed were less than additive, with the exception of the development of eosinophil colonies and clusters, where IL-3 and GM-CSF were found to act synergistically. In secondary cultures, proliferative responses to GM-CSF were strongly enhanced by preculture of CD34+ cells in IL-3 for four to 11 days, and to a lesser extent by preculture in GM- CSF. Finally, responses to IL-3 were not affected by preculture of CD34+ cells in the presence of GM-CSF. Our results indicate that there is a wide overlap of cells capable of proliferating either in response to IL-3 or to GM-CSF within the cord blood CD34+ compartment. However, differences in primary proliferation kinetics and increased responsiveness to GM-CSF following preculture suggest the importance of a sequential action of IL-3 and GM-CSF in the expansion of CD34+ cells.

Cytofluorometric and cytomorphologic analysis of human bone marrow cells derived fromstromal cultures stimulated by granulocyte‐macrophage colony‐stimulating factor, interferon‐γ and splenopentin pentapeptide

“…The higher expression of theTfR (a proliferation marker) on cells from cultures supplemented with GM-CSF is in agreement with these findings and coincides with an increase of progenitors (blasts) in GM-CSF-containing cultures. Furthermore, an increased number of GM-CSF was observed under similar conditions in earlier studies [14].…”

“…Furthermore, GM-CSF seems to promote an expansion of myeloid precursors and of more mature granulocytic cells (CDllc+, CD15+ and CD14-elements). Other authors have described the ability of GM-CSF to induce a generation of myeloid progenitors from CD34+ cells [14].We have shown that this process is connected with a decrease in the number of immature cells due to their maturation into CD34precursors. In agreement with the in vivo effects of GM-CSF, which caused an earlier increase of the number of granulocytes, but only a marginal and delayed production of monocytes [20], the in vitro effect of GM-CSF observed in this study may be due to the preferential stimulation of granulocytic differentiation.…”

“…Cytomorphological analysis of BM cells derived from stromal cultures(14 days) stimulated with GM-CSF and Sp-5. Absolute number of cells expressing several differentiation antigens…”

Modulation of human cord blood progenitor cell growth by recombinant human interleukin 3 (IL‐3), IL‐6, granulocyte‐macrophage colony stimulating factor (GM‐CSF) and stem cell factor (SCF) in serum‐supplemented and serum‐free medium

“…The same effect was observed for multipotent-colony forming units (CFU-GEMM) when SCF was added to interleukin 3 (IL-3) and erythropoietin (EPO). Moreover, on CD34' purified cord blood stem cells, an enhanced proliferation of CFU-GM was obtained in the presence of combinations of IL-3 and GM-CSF [6]. The same stimulatory effect was observed on bone marrow CFU-GM growth when SCF was associated with IL-3 or GM-CSF [7].…”

Biology of Human Umbilical Cord Blood‐Derived Hematopoietic Stem/Progenitor Cells

“…2). In this regard, several cytokines (including SCF, interleukin 1 (IL‐1), IL‐3, IL‐6, GM‐CSF, G‐CSF, M‐CSF, erythropoietin (Epo), thrombopoietin (Tpo), and FL have been assessed, either alone or in combination, in cultures of UCB‐derived CD34 + cells [10, 40, 48, 66‐77]. In terms of HPC expansion, the best results have been obtained when cytokines are used in combinations that include early‐acting factors, such as SCF, FL, and Tpo.…”