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Effect of puromycin and actinomycin D on a persistent mumps virus infection in vitro
Abstract:
Puromycin and actinomycin D were used to treat a line of human conjunctiva cells persistently infected with mumps virus (C-M cells) in order to determine where virus synthesis is inhibited. Although 90% of the cells in C-M cultures are infected, little or no infectious virus is produced by most cells in a growing culture. Adding puromycin to inhibit protein synthesis resulted in the production of infectious virus. Thus, all the viral proteins needed for virus completion were made in the growing cells. When actinomycin D was added to growing cells, infectious virus was again produced. Since mumps virus synthesis is actinomycin D-insensitive, this suggested a host control of the virus. Interferon was not detected. The possible mechanisms of host control are discussed.
Insights
Mumps virus (C-M cells) produced infectious virus when protein synthesis was inhibited with puromycin, indicating viral proteins were made. Actinomycin D also induced virus production, suggesting host control over mumps virus synthesis.
Area of Science:
- Virology
- Cell Biology
- Molecular Biology
Background:
- Human conjunctiva cells (C-M cells) persistently infected with mumps virus produce little infectious virus in growing cultures, despite high infection rates.
- Understanding the regulation of viral synthesis in persistently infected cells is crucial for controlling viral infections.
Purpose of the Study:
- To investigate the site of inhibition of mumps virus synthesis in persistently infected human conjunctiva cells.
- To elucidate the role of host cell mechanisms in regulating viral production.
Main Methods:
- Treatment of C-M cells with puromycin to inhibit protein synthesis.
- Treatment of C-M cells with actinomycin D to inhibit transcription.
- Monitoring infectious virus production following drug treatment.
Main Results:
- Puromycin treatment led to the production of infectious mumps virus, indicating that all necessary viral proteins were synthesized in untreated cells.
- Actinomycin D treatment also resulted in infectious virus production, suggesting a mechanism independent of direct transcriptional inhibition by the drug.
- The observed virus production patterns pointed towards host-mediated control of mumps virus synthesis, as interferon was not detected.
Conclusions:
- Mumps virus protein synthesis is not the primary site of inhibition in persistently infected C-M cells.
- Host cell factors appear to regulate mumps virus production, independent of interferon.
- Further investigation into cellular mechanisms controlling viral replication is warranted.