Response of the fetal liver cell lines to G-CSF.

Cells from the fetal liver cell lines continuously growing in SCF and IL-3 were washed and resuspended for 2 days in media containing GM-CSF alone to induce G-CSF receptor mRNA expression (Figure 4). These cells were then washed and resuspended (10⁵/mL) in culture media in the presence or absence of G-CSF (5 ng/mL). At the indicated time after culture initiation, the viable cell number was determined using trypan blue dye exclusion for the (A) FL-8(−/−) and (C) FL-1(+/−) cells. Wright-Giemsa stains of cytospin preps are shown for the (B) FL-8(−/−) and (D) FL-1(+/−) cells that were cultured in GM-CSF alone for 2 days, followed by G-CSF (5 ng/mL) alone for 4 additional days.