Effect of DEAE-Dextran on Interferon Production and Protective Effect in Mice Treated with the Double-Stranded Polynucleotide Complex Polyinosinic-Polycytidylic Acid

Abstract

Summary Interferon production by mice treated with the double-stranded polynucleotide complex I:C is increased up to 30 times by the presence of DEAE-dextran in injected I:C solutions. Consistent amounts of circulating IF could be detected only 90 min after treatment. The highest levels of circulating IF were produced within 3 hr after treatment with I:C (20 µg/mouse) and DEAE-dx (200 µg/mouse). The highest levels of circulating IF were maintained during a 10- to 12-hr period following a single stimulation. Repeated treatment of mice with I:C and DEAE-dx after the disappearence of previously induced IF were followed by new rises of IF production. If stimulation was repeated at the times when the previously induced level of circulating IF was still high, it was possible to maintain this level during the whole period of study (39 hr). Protection against challenge with Columbia SK virus was much higher in mice treated with repeated doses of inducer (90% survival) than in mice treated with a single dose of inducer (50% survival).