[Interferons produced by the cells of newborn mice in the presence of sera from newborn and adult animals].

Fibroblasts of newborn mice produced far less amount of interferon in the presence of sera from newborn animals than in the presence of sera from adult animals. The interferons obtained were purified by adsorption chromatography on porous glass and were analyzed by electrophoresis in polyacrylamide gel. It has been shown that antiviral activity of interferon preparations obtained in the presence of sera from newborn mice was associated with the fraction of 45 Kd. Addition into the growth medium of sera from adult animals led to the production by the same cells of interferon activity associated with 41 and 28 Kd fractions. It is assumed that the sera of newborn mice contained the components influencing the molecular content of interferon produced by the cells of newborn animals.