Persistence of Active Interferon in Cells Washed After Treatment With Interferon

Abstract

Summary

An inhibitor of virus action obtainable from cells washed after treatment with interferon at 4°C, but not from untreated cells, was presumably interferon. The quantity recovered amounted to approximately 1% of the interferon to which the cells had been exposed. Persistence of interferon could be demonstrated in cells extensively washed after exposure to interferon at 37°C by exposing the cells to interferon in the presence of puromycin (10y per ml) to block the virus inhibitory action of interferon. When the washed cells were again incubated at 37°C before they were infected with virus, they became resistant to virus synthesis without further exposure to interferon. The virus resistance developed by cells under these conditions was blocked by actinomycin D. The significance of these results is discussed in terms of the persistence of resistance to virus infection after interferon treatment and the probable half-life of interferon-induced RNA.