Inhibition by Exogenous Interferon of Replication of Poliovirus Ribonucleic Acid in Chick Brain.

Youngner, Julius S. (University of Pittsburgh, Pittsburgh, Pa.), and Marion E. Kelly. Inhibition by exogenous interferon of replication of poliovirus ribonucleic acid in chick brain. J. Bacteriol. 90:443-445. 1965.-The replication of poliovirus was studied after the intracerebral inoculation of infectious ribonucleic acid (RNA) into the brains of 2-day-old chicks; these animals are not susceptible to intact virus. Single-cycle replication of virus, which reached a peak in about 12 hr, was completely inhibited by prior intraperitoneal injection of interferon prepared from the allantoic fluid of chick embryos infected with influenza virus. A single dose of as little as 500 units of interferon, measured by a plaque-reduction method, completely suppressed viral replication when injected 24 hr prior to infectious RNA. This system provides a model for the study of the protection of target organs by passively transferred interferon injected at a distance.