A Luciferase-Fluorescent Reporter Influenza Virus to Track Viral Infections

Start with a pathogenic recombinant influenza virus with a genome modified to incorporate compact reporter genes.

These reporter genes encode a small luciferase bioluminescent enzyme and a monomeric fluorescent protein.

Inoculate the virus intranasally into an anesthetized mouse, appropriately shaved for subsequent imaging.

The virus enters the host cell and releases its genetic contents.

Inside the nucleus, the viral genome transcribes into mRNA molecules and subsequently translates to produce luciferase and fluorescent protein in the host cell.

Inject a luciferin substrate retro-orbitally into the mouse.

The luciferase enzyme oxidizes luciferin to oxyluciferin, which on relaxation, emits a bioluminescent signal.

Measure the signal to estimate luciferase levels, enabling viral infection monitoring in a live animal.

For ex vivo analysis, excise the lungs and capture the fluorescence signal through a suitable imaging technique.

Unlike regular variants, monomeric fluorescent proteins do not form aggregates, yielding a clear image to track viral infection accurately.