CDC researchers have developed a Madin-Darby Canine Kidney (MDCK) reporter cell line that is exceptionally permissive for influenza virus replication and provides a highly specific, sensitive approach for the simultaneous detection and isolation of influenza viruses. Simplified antibody neutralization assays and high-throughput antiviral drug screening can also be easily and efficiently implemented using this reporter system.

Laboratories generally rely on embryonated chicken eggs or mammalian cell cultures for isolation and propagation of influenza viruses. This approach is hampered by the relatively long times required to obtain test results (5 to 7 days) and substantial requirements for specialized materials, equipment and specially trained technician labor.

This CDC-generated reporter system for influenza A virus uses highly permissive MDCK cells expressing a luciferase-encoding amplicon controlled by canine RNA polymerase I (POL-I) promoter elements. This cell-based system exploits the specificity of viral transcription factors for their target promoters, and the extreme sensitivity of the luciferase enzyme greatly reduces turnaround times for readouts. In addition, the simplicity of these new reporter assays relative to ELISA and real-time PCR reduces technician labor, reagent/consumables usage, and physical lab space requirements when detecting and diagnosing influenza infection. This system will also be useful for efficient, high-throughput screening of antiviral drug libraries and neutralizing antibody assays.