Development of a plaque assay for a cytopathic, rapidly replicating isolate of hepatitis A virus

Area of Science:

• Virology
• Cell Biology
• Infectious Diseases

Background:

• Hepatitis A virus (HAV) replication in cell culture is typically nonlytic and slow.
• Previous studies lacked efficient methods for quantifying infectious HAV particles in vitro.

Purpose of the Study:

• To characterize a rapidly replicating HAV isolate (pHM-175).
• To develop a plaque assay for quantifying infectious HAV in cell culture.
• To demonstrate the utility of the plaque assay for HAV neutralization studies.

Main Methods:

• Serial passage of HAV strain HM-175 in cell culture to generate a rapidly replicating isolate (pHM-175).
• Induction of cytopathic effect by pHM-175 in FRhK-4 cells.
• Development and application of a plaque assay for pHM-175.
• Neutralization assays using polyclonal and monoclonal anti-HAV antibodies.

Main Results:

• A rapidly replicating HAV isolate (pHM-175) was generated.
• pHM-175 induced a significant cytopathic effect in FRhK-4 cells.
• A functional plaque assay for pHM-175 was established.
• The plaque assay successfully demonstrated neutralization of pHM-175 by HAV-specific antibodies.

Conclusions:

• The development of a plaque assay provides a valuable tool for studying HAV replication and antiviral strategies.
• Rapidly replicating, cytopathic HAV isolates can be generated and utilized for in vitro assays.
• This assay facilitates the characterization of HAV neutralization by antibodies.