Promotion of differentiation and proliferation of peripheral blood CD34+ cells in vitro by G-CSF.

G-CSF was found to synergize with IL-3 and SCF in inducing rapid proliferation of purified CD34+ cells and differentiation to multiple myeloid lineages. The stroma-free, cytokine-driven culture system could achieve a degree of amplification of colony forming cells, suggesting the feasibility of culture of hematopoietic progenitor cells in vitro as an adjunct to hematopoietic stem cell transplantation.