Isolation and characterization of a cloned growth factor dependent macrophage cell line, BAC1.2F5

The SV40 transformed murine macrophage cell line, BAC1, proliferates in response to the colony stimulating factor, CSF‐1 (Schwarzbaum et al., J. Immunol., 132:1158, 1984). In order to obtain a cell line suitable for biochemical and genetic studies of CSF‐1 signal transduction, clones of BAC1 were established. Clones ranged from being completely autonomous to being completely dependent on CSF‐1 for growth. Cells of one clone (2F5), which proliferated in response to either CSF‐1 or granulocyte‐macrophage CSF (GM‐CSF) were characterized in detail. The kinetics of receptor‐mediated internalization and intracellular destruction of CSF‐1 were comparable to the kinetics observed with peritoneal exudate macrophages. CSF‐1 was shown to regulate cell spreading, cell survival, protein degradation, and the duration of the G1 and S phases of the cell cycle. The 2F5 clone therefore exhibits a number of CSF‐1 stimulated responses and is being used for genetic and biochemical studies of CSF‐1 action.