Influence of interferon on the synthesis of virus particles in oncornavirus carrier cell lines. IV. Relevance to the potential application of interferon in natural infectious diseases.

That interferon reduced the release of C-type oncornavirus particles by chronically infected mouse cells was shown by radiolabeling of the particles with uridine or amino acids and by determination of particle-associated reverse transcriptase. The number of released particles, as determined by direct electron microscopic enumeration, was reduced to a lesser extent. In contrast, interferon failed to affect the number of budding particles and caused a slight increase in the number of completed particles present in the microspace contiguous to the cell membranes. A working hypothesis is that, in the presence of interferon, C-type particle assembly and release are slowed but not arrested; sizable numbers of particles continue to be assembled and released. Some of these particles may be defective in one or more proteins, such as reverse transcriptase or proteins necessary for final release. These in vitro data justify speculation that, in vivo, interferon may be expected to reduce tissue damage due to antigen-antibody complex formation, but not damage due to sytolytic immune attack on cells carrying the antigens.