Early 4-hydroxyperoxycyclophosphamide (4-HC) resistant hematopoietic progenitor cells (pre-colony-forming units, pre-CFU) were evaluated by a two-step liquid culture system, (earlier progenitors), pre-CFU, as well as by the conventional semi-solid mixed colony assay (later progenitors) for their growth response to interleukin-6 (IL-6), interleukin-3 (IL-3), and a combination of both factors. The effect of the IL-6/IL-3 combination was compared to that of IL-1/IL-3. IL-3 alone proved less effective in supporting earlier pre-CFU cells than later progenitor cells. In a previous work IL-6 promoted the growth of early multipotential progenitor cells circulating in hairy cell leukemia (HCL) patients. IL-6 alone did not stimulate growth of either early or later normal progenitor cells. However, a significant synergistic effect was obtained when IL-6 and IL-3 were added together (p <0.05). IL-6/IL-3 synergism was more potent than IL-1/IL-3 in promoting growth of colonies. The previously described synergistic effect of IL-1/IL-3 seems to be independent of IL-6. Thus, our results suggest that the multifunctional cytokine IL-6, may be of use in shortening the engraftment time in bone marrow transplantation.
Michalevicz, R.; Lifshitz, D.; and Revel, M.
"Interferon Beta 2/Interleukin-6 and Interleukin-3 Synergize in Stimulating Proliferation of Human Early Hematopoietic Progenitor Cells.,"
Scanning Microscopy: Vol. 3
, Article 14.
Available at: https://digitalcommons.usu.edu/microscopy/vol3/iss4/14