Corticosteroids block newly induced but not constitutive functions of macrophage cell lines: myeloid colony-stimulating activity production, latex phagocytosis, and antibody-dependent lysis of RBC and tumor targets.

Hydrocortisone at 10(-4) M added to macrophage cell lines had no effect on the following activities: J774.1 antibody-dependent phagocytosis and lysis of sheep RBC, RAW 264 antibody-dependent lysis of tumor targets, latex bead phagocytosis by PU5-1.8 cells, and constitutive production of myeloid colony-stimulating activity (CSA) by WEHI-3 cells. In contrast, 10(-4) M hydrocortisone completely inhibited LPS or PPD activation of the following functions: induced production of myeloid CSA, stimulation of latex phagocytosis and stimulation of antibody-dependent lysis of tumor targets by PU5-1.8 cell line, and stimulation of antibody-dependent lysis of RBC targets by RAW 264 cell line. Lower concentrations of hydrocortisone or dexamethasone at 10(-6) M inhibited the LPS induction of CSA from 55 to 90%. Growth inhibition of PU5-1.8 cells caused by 1 microgram/ml LPS was also partially reversed by corticosteroids. Thus, steroids block these newly induced but not constitutive functions of these macrophage cells in culture.