Persistent adenovirus infections of nonpermissive monkey cells

Persistent infections of monkey cells were established by using 2 serotypes of human adenovirus. The persistently infected cells show no morphologic changes, but continue to produce low titers of infectious adenovirus. The inapparent infection can, at any time, be converted to a cytolytic productive one by superinfection with simian virus 40. Persistence in this system does not appear to result from multiple rounds of lytic infection, nor is it mediated by production of defective interfering particles. The persistently infected cells do not possess the characteristics of oncogenic transformation. Results of these studies also show that the nonpermissiveness of monkey cells to adenovirus replication can be partially overcome by infection at high multiplicity.