Regulation of the Secretory Function of Mouse Peritoneal Mast Cells by IL-3, IL-4 and IFN-γ

We investigated IL-3 IL-4 and IFN-γ for regulatory effects on the IgE-mediated exocytotic secretory function of mast cells in vitro. Mouse peritoneal mast cells were incubated under cell culture conditions with purified mouse recombinant cytokines, either alone or in various combinations, for 48 h, and monoclonal IgE antibody was added for the second 24 h of culture. Exposure of the cells to IL-3 or IL-4 at only a few nanograms per millilitre led to an enhancement in 5-HT release upon subsequent challenge of the cells with antigen. In contrast, IFN-γ at comparable concentrations strongly inhibited 5-HT release, regardless of whether the cells had been maintained in the absence or presence of IL-3 and/or IL-4. We conclude that IL-3/IL-4 reciprocate with IFN-γ to regulate degranulation.