Related Experiment Videos
Preliminary characterization of a persistent infection of HeLa cells with human rhinovirus type 2
Abstract:
We were able to initiate a persistent infection (PI) in HeLa cells with a temperature-sensitive (ts-) mutant of rhinovirus type 2 (TS-1), but not with the corresponding wildtype (wt) virus. The ability to initiate a PI may be related to the multiplicity of infection. Persistence was established at 37 degrees C but not at 32 degrees C and the virus isolated from the PI was no longer temperature-sensitive. Infectious virus was continually produced at low levels throughout the course of the PI and cell cultures underwent multiple episodes of partial destruction (crisis) and subsequent recovery. PI virus and the initiating virus were neutralized to the same extent by hyperimmune polyclonal TS-1 antiserum indicating that no significant change had occurred with respect to serological type. The presence of either interferon or virus-related interfering activity could not be demonstrated in the PI cultures. Superinfection experiments in cells that were 'cured' of PI virus indicated the selection of a cell population during persistence that could no longer support the growth of homologous-type virus. This effect became less pronounced upon further passage of the cured cells. When compared with the wt and ts viruses, the PI virus yielded comparable amounts of infectious virus in HeLa cells but with decreased synthesis of RNA.
Insights
A temperature-sensitive rhinovirus mutant established a persistent infection in HeLa cells, producing infectious virus and altering cell susceptibility. The evolved virus lost its temperature sensitivity and showed reduced RNA synthesis.
Area of Science:
- Virology
- Cell Biology
- Infectious Diseases
Background:
- Persistent viral infections are a significant challenge in virology and medicine.
- Understanding the mechanisms of viral persistence is crucial for developing effective antiviral strategies.
- Rhinoviruses, common causes of the human cold, can establish persistent infections under specific conditions.
Purpose of the Study:
- To investigate the establishment and characteristics of persistent rhinovirus infections in HeLa cells.
- To determine the properties of a temperature-sensitive rhinovirus mutant during persistent infection.
- To elucidate cellular changes associated with rhinovirus persistence.
Main Methods:
- Infection of HeLa cells with a temperature-sensitive (ts-) rhinovirus type 2 (TS-1) mutant.
- Culturing infected cells at different temperatures (37°C and 32°C) to establish persistent infection (PI).
- Characterization of the PI virus, including temperature sensitivity, serological typing, and RNA synthesis.
- Superinfection experiments with cured cells to assess cellular resistance.
Main Results:
- A persistent infection (PI) was successfully initiated with the ts- mutant at 37°C, but not with the wildtype virus.
- The virus isolated from the PI cultures was no longer temperature-sensitive and retained its serological type.
- PI cultures continuously produced low levels of infectious virus, with recurring cell destruction and recovery.
- Cured cells exhibited reduced susceptibility to homologous rhinovirus growth, indicating selection of resistant cell populations.
Conclusions:
- Temperature-sensitive rhinovirus mutants can establish persistent infections in HeLa cells, leading to viral evolution.
- Persistent infection involves continuous low-level virus production and cyclical cell damage/recovery.
- HeLa cells develop resistance to homologous virus infection during persistent rhinovirus infection.
- The evolved PI virus exhibits altered characteristics, including loss of temperature sensitivity and reduced RNA synthesis.