[Defective interfering mumps virus produced by chronically infected cell cultures]

Area of Science:

• Virology
• Cell Biology

Background:

• Mumps virus is a significant human pathogen.
• Understanding viral replication and interference is crucial for developing antiviral strategies.

Purpose of the Study:

• To characterize the properties of virus and defective interfering particles (DIP) produced during chronic mumps virus infection.
• To investigate the interfering activity of DIP against the parent mumps virus.

Main Methods:

• HEp-2 and L-41 cell cultures were chronically infected with mumps virus.
• Virus and DIP yields were quantified (PFU/ml).
• DIP were analyzed for polypeptide composition, RNA size, and interfering activity.

Main Results:

• Chronic infection yielded significant amounts of small-plaque, slow-replicating mumps virus (10(2)--10(3) PFU/ml).
• Defective interfering particles (DIP) were produced in substantial quantities.
• DIP shared similar polypeptide composition with the parent virus and contained subgenomic RNA.
• DIP demonstrated marked interfering activity against the original mumps virus.

Conclusions:

• Chronic mumps virus infection leads to the generation of defective interfering particles (DIP).
• These DIP possess characteristics of both virus and defective genomes, including interfering capabilities.
• The findings contribute to understanding viral interference mechanisms and potential therapeutic targets.