Production of Colony-Stimulating Factor in Mitogen-Stimulated Lymphocyte Cultures

Abstract The addition of phytohemagglutinin, pokeweed mitogen, concanavalin A or bacterial lipopolysaccharide to mouse spleen cultures strongly stimulated production of colony-stimulating factor (CSF), the humoral regulator of granulopoiesis and macrophage formation. Column-filtered spleen cells depleted of macrophages exhibited similar responses. Cultures of macrophage monolayers failed to produce elevated levels of CSF when stimulated by PHA or PWM. The results suggest that activated T- and B-lymphocytes can both produce significant amounts of CSF, providing a possible mechanism for stimulating macrophage formation in chronic immunologic or inflammatory responses.