The glycoprotein nature of murine gamma interferon

Synthesis of murine gamma interferon (MuIFN gamma) by phytohemagglutinin (PHA)-stimulated spleen cells was inhibited in a dose-dependent manner by graded concentrations of tunicamycin or 2-deoxy-glucose, both of which inhibit glycosylation. The homologous (murine) and heterologous (rat) antiviral activities of the MuIFN gamma preparations secreted in the presence of the various concentrations of either glycosylation inhibitor were reduced to similar degrees. MuIFN gamma synthesized in the presence of tunicamycin (tunicamycin-MuIFN gamma) exhibited a lower molecular weight (MW), a lack of binding to immobilized Concanavalin-A (Con A), and different charge properties when compared to MuIFN gamma produced in absence of inhibitor (control-MuIFN gamma). Potent rabbit and rat neutralizing antibodies raised against a control-MuIFN gamma subcomponent, isolated by its specific binding to a Con A affinity column, neutralized the antiviral activity of tunicamycin-MuIFN gamma to the same degree as the immunogen.