A rabies virus persistent infection in BHK21 cells

Area of Science:

• Virology
• Cell Biology
• Infectious Diseases

Background:

• Persistent viral infections can lead to significant alterations in viral properties.
• Understanding viral evolution in vitro provides insights into host-pathogen interactions.

Purpose of the Study:

• To investigate the long-term effects of persistent rabies virus infection on viral characteristics in cell culture.
• To analyze changes in viral polypeptides during prolonged in vitro infection.

Main Methods:

• Establishment and maintenance of persistent rabies virus infection in BHK21 S13 cells for over 4 years.
• Monitoring viral plaque size and infectivity over multiple passages.
• Analysis of viral antigens using [35S]methionine labeling, immunoprecipitation, and polyacrylamide gel electrophoresis.

Main Results:

• A shift from large plaque to small plaque rabies virus variants occurred within the first 20 passages.
• Infectious virus was undetectable in the medium after 200 passages, indicating a defective state.
• Changes in glycoprotein size and M1 polypeptide structure were observed after the 20th passage, with further modifications in the defective state.
• Virus isolated from late passages showed altered polypeptide composition and reduced pathogenicity in vivo.

Conclusions:

• Persistent rabies virus infection in cell culture results in viral adaptation and loss of infectivity.
• Specific viral polypeptides, including glycoprotein and M1, undergo modifications during prolonged in vitro culture.
• These changes correlate with a loss of pathogenicity, highlighting the complex interplay between virus and host cells during persistent infection.