Rapid and transient rise in diacylglycerol concentration in Daudi cells exposed to interferon.

Human beta-interferon stimulates a 4-fold increase in the concentration of diacyglycerol and a 2-fold increase in the concentration of inositol monophosphate in Daudi (human B-lymphoblastoid) cells within 30 sec of exposure of the cells to interferon. The increase in diacylglycerol and in inositol monophosphate is transient and the concentrations of these compounds decrease to basal levels within 10 min. Preincubation of human beta-interferon with anti-interferon antibodies inhibits this effect as well as the binding of interferon to Daudi cells. Diacylglycerol concentrations were unaffected in mouse A9 cells (fibroblasts) incubated with human beta-interferon and in Daudi cells incubated with human gamma-interferon. Mouse A9 cells are insensitive to human interferon and Daudi cells are insensitive to human gamma-interferon. The magnitude of the increase in diacylglycerol concentration stimulated by interferon can be correlated to the interferon-induced inhibition of Daudi cell division in a dose-responsive manner. Phorbol 12-myristate 13-acetate also inhibits Daudi cell division in a dose-responsive manner. It is likely that the sharp and transient increase in diacylglycerol concentration represents one of the early biochemical changes in Daudi cells exposed to interferon.