Suppressive Effect of Interferon on the Humoral Immune Response to Sheep Red Blood Cells in Mice

Swiss-Webster mice injected intravenously with interferon preparations 2 days before primary or secondary immunization with sheep erythrocytes showed a significant suppression of their hemolysin and agglutinin responses as measured in microtiter assays. Interferon treatment in vivo also inhibited DNA synthesis induced in mouse lymphocytes studied in vitro by concanavalin A, phytohemagglutinin, and lipopolysaccharide. In addition, it suppressed the in vitro primary and secondary response to sheep erythrocytes. It is possible that this inhibition of the immune response by interferon is significant in the immunosuppression observed during viral infection or after administration of nonspecific mitogens, or perhaps even in the control of the normal immune response.