Persistent SV5 virus infection in continuous cell cultures.

Area of Science:

• Virology
• Cell Biology
• Microbiology

Background:

• Continuous cell lines are crucial for studying viral infections.
• Spontaneous infections can occur in cell cultures, requiring careful characterization.
• Parainfluenza virus SV5 is a known respiratory pathogen.

Purpose of the Study:

• To investigate spontaneous infections of parainfluenza virus SV5 in continuous cell lines.
• To characterize the behavior and persistence of SV5 in CGPK/H and L/H cells.
• To determine if the infection leads to cytopathic effects or production of infectious virus.

Main Methods:

• Cultivation of guinea pig kidney (CGPK/H) and mouse fibroblast (L/H) cell lines.
• Monitoring for cell degeneration and syncytia formation.
• Detection of viral antigens, ribonucleoprotein (RNP), and complete virions using immunological and morphological techniques.
• Assessing haemadsorption and neutralization assays with SV5 antiserum.

Main Results:

• Spontaneous infection with parainfluenza virus SV5 was identified in CGPK/H and L/H cells.
• No significant cell degeneration or syncytia formation was observed.
• Viral ribonucleoprotein (RNP), complete virions, and SV5 antigens were consistently reproduced.
• Focal haemadsorption, neutralized by SV5 antiserum, was detected.
• The infection remained persistent for over two years of observation.

Conclusions:

• Continuous cell lines can harbor persistent, non-cytopathic parainfluenza virus SV5 infections.
• SV5 can replicate and produce viral components without causing overt cell damage.
• These findings highlight the importance of sensitive detection methods for identifying persistent viral infections in cell cultures.