Defective interfering particles of encephalomyocarditis virus

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Encephalomyocarditis virus (EMC) is a significant pathogen.
• Understanding viral evolution and adaptation is crucial for disease control.
• Serial passage in cell culture can induce viral genetic changes.

Purpose of the Study:

• To investigate the effects of extensive serial passage on EMC virus.
• To identify potential genetic alterations and their functional consequences.
• To determine if defective interfering particles are generated during EMC virus passage.

Main Methods:

• Serial passage of EMC virus and its temperature-sensitive mutants in HeLa, L929, and BHK-21 cells.
• Equilibrium centrifugation in CsCl density gradients to analyze viral particles.
• Electrophoresis of viral RNA to assess molecular weight and integrity.

Main Results:

• High-passage EMC virus populations contained standard virus and particles with reduced RNA molecular weight.
• Three distinct high-passage isolates demonstrated interference with standard EMC virus replication.
• Evidence suggests the generation of defective interfering particles (DIPs) during serial passage.

Conclusions:

• Extensive serial passage of EMC virus in cell culture leads to the generation of defective interfering particles.
• These DIPs possess altered RNA genomes and can interfere with the replication of standard EMC virus.
• The findings provide insights into viral adaptation mechanisms and the emergence of defective viral genomes.