Replication-competent influenza A viruses expressing a red fluorescent protein

Area of Science:

• Virology
• Molecular Biology
• Infectious Diseases

Background:

• Studying influenza A virus (IAV) in model systems typically requires secondary labeling methods to identify infected cells, complicating research.
• Developing efficient tools for real-time monitoring of IAV infection is crucial for understanding viral pathogenesis and evaluating antiviral strategies.

Purpose of the Study:

• To generate replication-competent, red fluorescent influenza A viruses for simplified detection of infected cells.
• To evaluate the utility of these novel viruses in preclinical models for monitoring viral replication kinetics.

Main Methods:

• Generation of replication-competent influenza A viruses encoding mCherry fused to the non-structural 1 (NS1) protein.
• In vitro characterization of viral growth kinetics, neutralization by antibodies, and inhibition by antivirals.
• In vivo studies in mice to monitor viral replication in whole excised lungs using an in vivo imaging system (IVIS).

Main Results:

• Influenza A mCherry viruses exhibited growth kinetics comparable to wild-type virus in vitro.
• Infection with influenza A mCherry viruses was effectively neutralized by monoclonal antibodies and inhibited by antivirals.
• Lethal infection was established in mice, allowing for dose- and time-dependent monitoring of viral replication in lungs via IVIS.

Conclusions:

• Influenza A mCherry viruses serve as a valuable tool for real-time visualization of infected cells, eliminating the need for secondary labeling.
• These fluorescent viruses facilitate the characterization of influenza A virus and the identification of new therapeutic targets.
• The developed viruses offer a streamlined approach for studying influenza A pathogenesis and antiviral efficacy in preclinical models.