WARF: P99264US
Recombinant Influenza Viruses for Vaccines and Gene Therapy

INVENTORS

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Yoshihiro Kawaoka, Gabriele Neumann

Influenza viruses show strong potential as vaccine and gene delivery vectors: they do not replicate through DNA intermediates (which may incorporate into the host genome); they elicit strong immune responses; and they exist in a wide range of antigenic variants, allowing repeated immunization and long-term use. However, influenza viruses have proven difficult to manipulate in the laboratory. As negative strand RNA viruses with viral RNA (vRNA) complementary to messenger RNA (mRNA), their replication requires a complex unit composed of viral polymerase and other proteins, which both replicates vRNA and transcribes it into mRNA for protein synthesis by the host cell. To generate genetically modified influenza virus, engineered vRNA must be assembled into these replication units, a process that is both laborious and inefficient. UW-Madison researchers have now developed a method to efficiently generate fully constructed, artificial influenza virus. The method involves transforming a host cell with 10 DNA plasmids, each containing a DNA copy of a segment from the influenza viral genome. Nine of the plasmids express proteins needed for viral replication and assembly, while the tenth contains a transgene inserted between an RNA pol I promoter and a terminator, for gene expression.

• More rapidly generating and studying lethal mutations in viral processes, such as formation, packaging, binding and fusion, which may be useful targets for vaccines 
• Should allow development of improved gene therapy vectors because the researchers have also shown they can deliver a transgene without generating active virus in the recipient cell

• Allows manipulation of the influenza viral genome as DNA, which is more stable and easier to handle than RNA
• System is highly efficient, both in the infection of host cells and the yield of genetically modified virus particles (>10⁴ infectious particles/milliliter).
• Potentially applicable to other viruses, such as paramyxoviruses and rhabdoviruses

The researchers have demonstrated expression of the reporter gene GFP using this system. For current licensing status, please contact our team at licensing@warf.org or phone 608.262.4924. (Clicking this link will open a contact form in a popup window. If you have problems viewing the form, try disabling your popup blocker software.)