title: Induction of virus multiplication in permissive cells transformed by a temperature-sensitive polyoma virus. I. Isolation and partial characterization of survivors.
abstract: A fibroblastic cell line transformed by ts-P155, an early temperature-sensitive mutant of polyoma virus, has been isolated after infection of secondary mouse embryo cells at the restrictive temperature of 39. These cells, designated Cyp, undergo a massive CPE accompanied by the production of infectious, temperature-sensitive virus when transferred to the nonrestrictive temperature of 33. Several independent clones were established from cells which survived the induction of virus multiplication occurring at 33. When routinely cultured at this temperature, these cells, termed R, displayed the growth properties of transformants and produced variable amounts of infectious, temperature-sensitive virus. This shedding of virus could not be "cured' by the addition to the culture medium of antipolyoma serum which had already been found to effectively suppress virus production in Cyp cell cultures transferred to 33. Moreover, R cells seemed to have developed a resistance to superinfection that the parent Cyp cell line did not exhibit. Therefore, virus production in R cell cultures probably reflects the occasional excision and replication of integrated viral genomes rather than a carrier state.
mesh_terms: D000956:Antigens, Viral / Q000032:analysis; D002460:Cell Line; D002472:Cell Transformation, Viral; D003588:Cytopathogenic Effect, Viral; D004279:DNA, Viral / Q000096:biosynthesis; D009154:Mutation; D010641:Phenotype; D011120:Polyomavirus / Q000502:physiology*; D013696:Temperature; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral