Regulation of mRNA levels of TNF-alpha and the alpha chain of the high-affinity receptor for IgE in mast cells by IFN-gamma and alpha/beta.

Rat mast cell lines (hybrid rat mast cells, HRMC, and rat cultured mast cells, RCMC) and mast cells from the rat body cavity were used to test the hypothesis that IFN-alpha/beta and IFN-gamma inhibit tumor necrosis factor alpha (TNF-alpha)-mediated cytotoxicity by depressing the steady-state levels of mRNA for TNF-alpha. In vitro treatment of mast cells with IFN-gamma and IFN-alpha/beta depressed mRNA levels. By contrast, IFN pretreatment of mast cell lines induced an increase in levels of mRNA for the IFN-inducible gene, 2'5'-oligoadenylate synthetase and also for high-affinity IgE-receptor-alpha. The IFN-mediated regulation of mast cells may be an important mechanism in the control of inflammatory pathways characterized by Th1- and Th2-type responses.