Effect of colony-stimulating factors on the proteins synthesized by normal and leukemic myeloid progenitor cells.

The proliferation and differentiation of normal granulocyte-macrophage (GM) progenitor cells is dependent on the presence of GM colony stimulating factor (GM-CSF). The proliferation of primary leukemic cells is also dependent on GMCSF, and some established myelomonocytic cell lines (e.g., WEHI3B D+) can be induced to differentiate by G-CSF. Using fluorescence-activated cell sorting, it has been possible to isolate highly purified granulocyte-macrophage colony forming cells (GM-CFC) [I I]. Fetal liver cells can be labeled with fluorescent pokeweed mitogen and the GM-CFC sorted on the basis of fluorescence intensity and light scatter. We have initiated an analysis of the 35S-labeled proteins in GM-CFC using two-dimensional gel electrophoresis [12]. In particular, the protein changes induced in GM-CFC by macrophage colony stimulating factor (M-CSF) [14], GM-CSF [4], and other hemopoietic regulators [5] have been monitored in an attempt to understand the extent and function of the protein synthetic events associated with commitment to differentiation or proliferation.