Effect of interferon on protein glycosylation and comparison with tunicamycin

Abstract

The present wide interest in the mechanism of action of interferon (IFN) stems from its antiviral and anticancer potential. Possibly one of the more interesting insights into the antiviral action of IFN was recently described by Maheshwari et al.¹. These authors, including one of us (K.O.), reported that IFN-treated cells release viral particles with low infectivity, and that this low infectivity seems to be related to the reduced amount of membrane protein glycosylation. The implications of this suggestion are exciting because inhibitors of glycosylation have antiviral properties, and also selectively kill transformed cells (see ref. 2 for review). An effect of IFN on the sysnthesis and cell-surface expression of glycoproteins could have an important role in its antiviral, anticancer and immunoregulatory actions. We have examined, for the first time, the effect of IFN on glycosylation of cellular proteins. We used murine fibroblasts (L-cells and NIH-3T3), plasmacytoma cells (P3 × 63 Ag8) and vesicular stomatitis virus (VSV) to compare the action of IFN with tunicamycin (TM), a known inhibitor of glycosylation². Our results indicate that IFN does not inhibit the glycosylation of cellular or viral glycoproteins. Cells treated with IFN do not produce nonglycosylated species of glycoproteins nor the ‘glucose/glycosylation regulated proteins’³ (GRPs), in contrast to cells treated with tunicamycin⁴.