Interferon and an Interferon Antagonist

摘要

Previous research has found crude Newcastle disease virus (NDV) - induced interferon produced in L-929 cell cultures to be highly effective in protecting these cells against Mengovirus but totally incapable of protecting mouse-passaged Ehrlich ascites tumor (EAT) cells. This anamolous intraspecies specifity was due to the presence in the crude material of an interferon antagonist. Adsorption on CM Sephadex C25 and elution with a rising pH gradient effected isolation of semipurified interferon, fully protective of EAT cells, as well as separation of the antagonist. The latter eluted in two positions - one just after the loading volume and the other just prior to interferon elution. This report further characterizes the antagonist by biochemical and biological parameters.