Development of a Method That Delivers Drugs to Enveloped Viruses

Hepatitis C virus (HCV) infection leads to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma in 50-80% of the cases. Interferons (IFNs) and the nucleoside analog ribavirin form the basis of the treatment of this infection but are not considered sufficiently effective and cause several side effects. In this study, we developed a novel viral-specific drug delivery method. Enveloped viruses, including HCV, expose an anionic phospholipid, phosphatidylserine (PS), on their surface to mediate their binding and entry into cells for infection. To target such exposed PS on HCV, we developed a chimeric recombinant protein containing human IFN and mouse lactadherin (also known as milk fat globule epidermal growth factor 8), which binds with high affinity to PS. The IFN-lactadherin fusion protein showed a high binding affinity toward PS and HCV and consequently blocked viral replication in the infected cells more efficiently than conventional IFN. Overall, these data suggest that conjugation with lactadherin facilitates the delivery of any protein drug to PS-exposing enveloped viruses.