Figure 5.

Effects of cytokines on CD36E proliferation. (A) CD36E cells were cultured under various conditions in which cytokines alone or in combination were excluded from the original serum-free expansion medium or replaced by 100 ng/mL thrombopoietin. These cultures were compared with cells grown in the standard cytokine cocktail (3 IU/mL EPO + 100 ng/mL SCF + 5 ng/mL IL-3). Cell proliferation was measured at indicated time points in triplicate by Trypan blue staining. Indicated cytokine amounts, 3 IU, 100 ng, and 5 ng, are per mL. (B) CD36E cells were grown in serum-free expansion medium supplemented with higher concentrations (three- or nine-fold) of EPO and/or SCF alone or in combination. Because IL-3 had no effect on CD36E proliferation, the cytokine was kept at a constant 5 ng/mL in all conditions. The cultures were compared with the standard cytokine concentrations of 3 IU/mL EPO and 100 ng/mL SCF. Cell proliferation was monitored on various days in triplicate culture conditions.