Effect of interferon on murine leukaemia virus infection. IV. Formation of non-infectious virus in chronically infected cells.
Interferon (150 units/ml) was used to treat SC-1 and AKR-2B cells which were chronically infected with murine leukaemia virus (MuLV). This led to a 100-fold decrease in the amount of infectious virus released into the medium and a 10-fold decrease in the number of virus particles measured by the virion-associated reverse transcriptase assay. However, there was little change in the amount of cell-associated infectious virus, though nearly twice as many cell-associated virions were counted in electron micrographs. With both types of cells, interferon blocked MuLV replication at the post-budding stage, but it did not change the morphology of the particles produced or their content of virion 70S RNA. Infectious virus assembled on the cell membranes of interferon-treated cells was less stable at 37 degrees C than that grown in the absence of interferon. Release of infectious virus from interferon-treated cells was not inhibited by actinomycin D or cycloheximide, though both agents inhibited virus production in controls. These results show that interferon inhibits MuLV replication through effects on virion assembly; these lead both to the formation of non-infectious particles and of fewer virions. Kinetic analysis further shows that interferon affects MuLV assembly rapidly and induction of an antiviral protein may not be required.
D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D006358:Hot Temperature; D007372:Interferons / Q000494:pharmacology*; D009052:Leukemia Virus, Murine / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
D003609:Dactinomycin; D007372:Interferons; D003513:Cycloheximide; D012194:RNA-Directed DNA Polymerase