Upregulation of Type I Interferon Receptor by IFN-gamma

Abstract

Type I interferon (IFN) receptor has a multichain structure composed of at least two distinct subunits, IFNAR-1 and IFNAR-2. In the present study, we demonstrated that IFN- gamma induced the expression of mRNA for IFNAR-1 and IFNAR-2 in a human hepatoma cell line, HepG2 cells. The induction was dose and time dependent. Because of this result, we examined the effect of combined treatment with type I IFN and IFN- gamma . The intracellular 2-5A-synthetase activity induced by combined treatment was significantly higher than that by type I IFN alone. This study suggests that combined treatment with type I IFN and IFN- gamma may be more effective than that of type I IFN alone and that the upregulation of type I IFN receptor may be one of the reasons. Our findings may have some relevance to the clinical use of IFN.