Reinfection-induced increase of rubella persistently infected cells in a macrophage-like cell line

Area of Science:

• Virology
• Immunology
• Cell Biology

Background:

• Persistent viral infections can establish chronic disease states.
• Murine macrophage models are crucial for studying host-pathogen interactions.
• Understanding rubella virus persistence is key to managing congenital rubella syndrome.

Purpose of the Study:

• To establish and characterize a long-term murine macrophage cell culture persistently infected with rubella virus.
• To investigate the effects of viral reinfection on the proportion of infected cells and viral production.
• To assess the stability of the infected cell culture over extended passages.

Main Methods:

• Establishment of immortalized murine macrophage cell line.
• Infection with rubella virus and subsequent reinfection.
• Quantification of viral antigen expression using immunofluorescence.
• Measurement of infectious virus production via TCID50 assays.
• Monitoring of extracellular virus titers over serial passages.

Main Results:

• Initial infection resulted in 35-50% antigen-positive cells and low infectious virus production (0.05-1.5%).
• Reinfection increased antigen-positive cells to 75-90% and infectious virus producers to 30-45%.
• Extracellular virus titers stabilized between 10(2)-10(3) TCID50/ml post-reinfection and remained stable for over a year.

Conclusions:

• A stable, long-term rubella virus-persistent murine macrophage culture was successfully established.
• Reinfection is an effective strategy to increase the proportion of persistently infected cells and stabilize viral output.
• This model provides a valuable tool for studying rubella virus persistence and pathogenesis.