P-CELL STIMULATING FACTOR AND GLUCOCORTICOIDS OPPOSE THE ACTION OF INTERFERON-GAMMA IN INDUCING IA ANTIGENS ON T-DEPENDENT MAST-CELLS (P-CELLS)

Abstract

The expression of Ia antigens of cultured lines of T-dependent mast cells (TDMC) or persisting (P) cells was modulated by three hormones: interferon-gamma (IFN-gamma), P cell-stimulating factor (PSF), and glucocorticoids. The induction of Ia antigens by cloned IFN-gamma was inhibited by a homogeneous preparation of PSF, the T cell-derived factor that TDMC require for their in vitro growth. This inhibitory effect of PSF was dose-dependent and could not be overcome by increasing the levels of IFN-gamma. Other cytokines such as granulocyte/macrophage colony-stimulating factor, T cell growth factor, and L cell-derived macrophage colony-stimulating factor had no inhibitory effect. Thus, two diffe..