1956-57

Isaacs and Lindenmann discover interferon, an “antiviral penicillin” that was cellular rather than a virus and was identified in 1957 by their collaborator, biochemist Derek Burke, as a protein: “Burnet’s intuition [that interferon was a cellular rather than a virus product] proved sound. Interferon ultimately turned out to be a molecule made by cells in response to infection by viruses; under duress, these cells oozed the molecule into the broth of biochemical liquid outside the cells in order to alert other cells in the vicinity to steel themselves against impending viral attach. It was, in short, a cell-to-cell signal, a neighborhood alert, a civil defense siren at the level of cells. Many years later, this family of molecule – there are now known to be many – would become known as cytokines” (Hall, 139ff; quote at 145).