A hemopoietic cell line dependent upon a factor in pokeweed mitogen-stimulated spleen cell conditioning medium.

A continuously growing cell line (FMP1.1) has been isolated, which is dependent upon a factor in PWCM for both growth and survival. FMP1.1 appears to be a mast cell, since IgE receptors are present and their granules react specifically with a mast cell granule stain. The factor in PWCM may be a glycoprotein and has biochemical properties in common with PWCM factors, which stimulate at least four other lineages of hemopoietic colony-forming cell. This line provides a pure population of cells as a model for studying molecular events of hemopoietic precursor cell growth and differentiation.