Rubella virus maturation and production in two host cell systems

Area of Science:

• Virology
• Cell Biology

Background:

• Rubella virus is a significant human pathogen.
• Understanding rubella virus replication in different cell lines is crucial for vaccine development and antiviral research.

Purpose of the Study:

• To compare rubella virus replication and maturation in Vero and BHK21 cells.
• To characterize the ultrastructure of rubella virus particles and their assembly sites.

Main Methods:

• Inoculation of Vero and BHK21 cells with rubella virus at a consistent multiplicity of infection (MOI).
• Quantification of infectious rubella virus in culture medium and cell lysates at 24 hours post-infection.
• Electron microscopy to examine viral particle morphology and intracellular maturation sites.

Main Results:

• Vero cells released more infectious rubella virus extracellularly compared to BHK21 cells.
• BHK21 cells produced higher levels of intracellular infectious rubella virus.
• Rubella virus maturation in BHK21 cells was observed at the plasma membrane and within cytoplasmic compartments, including the Golgi apparatus and vacuoles.
• Viral particles exhibited a core, capsid, and envelope, with aberrant forms noted in vacuoles and at the plasma membrane.

Conclusions:

• BHK21 cells support higher intracellular rubella virus replication and maturation compared to Vero cells.
• Rubella virus assembly occurs at the plasma membrane and within cytoplasmic organelles in BHK21 cells.
• Distinct cellular compartments are involved in rubella virus replication, offering potential targets for antiviral strategies.