Virus interference. I. The interferonAlick Isaacs, J. Lindenmann|Proceedings of the Royal Society of London. Series B, Biological sciences|1957 Abstract During a study of the interference produced by heat-inactivated influenza virus with the growth of live virus in fragments of chick chorio-allantoic membrane it was found that following incubation of heated virus with membrane a new factor was released. This factor, recognized by its ability to induce interference in fresh pieces of chorio-allantoic membrane, was called interferon. Following a lag phase interferon was first detected in the membranes after 3 h incubation and thereafter it was released into the surrounding fluid.
Virus interference. II. Some properties of interferonAlick Isaacs, J. Lindenmann, R. C. Valentine|Proceedings of the Royal Society of London. Series B, Biological sciences|1957 Abstract Interferon could be titrated by the amount of interference induced in fragments of chorio-allantoic membranes challenged with influenza A virus. Over a ten-fold range, inverse proportion between interferon concentration and haemagglutinin titre reached by the challenge virus was observed. Interferon proved stable at 2°C for 2 weeks. Marked inactivation took place after 1 h at 60°C. Interferon was not measurably sedimented by 100 000 g for ½ h. It was held back by gradocol filters of a. p. d. 0.6 μ. It was not dialyzable. Interferon was active against influenza A, Sendai, Newcastle disease and vaccinia viruses. It was not neutralized by anti-MEL rabbit serum and only slightly inhibited by pooled human serum rich in complement-fixing antibody to influenza A soluble antigen.