Multiple pathways of interferoninduced gene expression in murine macrophages

Abstract: Steady-state levels of mRNAs that encode specific FcyR and Ia antigen genes have been measured in macrophages treated with interferons (IFNs) to examine the induction of these markers at the molecular level. Our previous studies suggested requirement for protein kinase C (PKC) in the IFN induction of these macrophage sur-face markers, although a difference in PKC dependence was found between IFN-a/fl- and IFN-y-induced FcR expression. The protein kinase antagonist H7, used pre-viously to distinguish between the surface induction of Fc-yR by IFN-a//3 and IFN-’y, also distinguishes between the IFN-a and IFN-y in the induction of FcyRI mRNA and Fc-yRI surface expression. Protein kinase inhibitors blocked the IFN-y induction of Ia mRNA in a manner similar to that reported previously for cell surface Ia ex-pression. It is concluded that Fc-yRI is induced by both IFN-a and IFN-y through distinct biochemical pathways, whereas IFN-y utilizes distinct pathways to induce the two macrophage activation markers, Ia antigen an