Plasticity of Cells and Ex Vivo Production of Red Blood Cells

Figure 2

Culture protocol to establish erythroid progenitor cell lines from embryonic stem cells. In most cases, the cells failed to proliferate within two months of the initial induction of differentiation from ES cells. Induced cells that could proliferate continuously for approximately two months (60 days) were subsequently cultured in the absence of OP9 cells and in the presence of hematopoietic humoral factors. Cells that could proliferate in the absence of OP9 cells were cultured further. Approximately four months after the initial induction of differentiation of the cells, we evaluated the factors that were essential for the proliferation of each cell line. VEGF, vascular endothelial growth factor; IGF-II, insulin-like growth factor-II; SCF, stem cell factor; EPO, erythropoietin; IL-3, interleukin-3.