Studies on the mode of action of IME--an inhibitor of interferon activity from mouse embryo tissues.

IME--inhibitor of interferon activity from mouse embryo tissues does not inactive interferon by direct contact; it does not inhibit the production of interferon and it does not affect the replication of challenge virus. IME shows no species-specific activity since it exhibits anti-interferon action not only in homologous interferon system but also in the heterologous rat, chick and human interferon systems. The interferon-induced antiviral state as well as the efficient cell's metabolism appear to be necessary for the expression of activity of IME.