Interactions of interferons in the induction of histocompatibility antigens in mouse fibroblasts and glial cells

The interactive effects of interferons (IFN) in the induction of class II major histocompatibility complex (MHC) antigens in a murine fibroblast line and murine glial cells (primary astrocytes and an oligodendroglioma line) were examined. It was found that IFN-alpha and -beta were additive with IFN-gamma in the induction of class I antigens but that both IFN-alpha and -beta down-regulated the induction of class II antigens by IFN-gamma. This was most clear cut when the IFN-alpha or -beta was present in large excess in terms of anti-viral activity. Recombinant IFN-alpha 2 was found weakly to induce class II antigens, unlike natural IFN-alpha. The results imply that IFN-alpha and -beta may be important in the control of class II antigen expression in vivo although not by themselves inducing class II antigens.