Combating Infectious Diseases:Engineering Strategies for Molecular Virology

Throughout history, infectious diseases have shaped population demographics, hindered economic potential, and most critically robbed far too many individuals of their lives. Despite advances in therapeutic drugs and tools, much work remains towards the eradication of infectious diseases. Our studies will focus on using engineering strategies to target the Hepatitis C virus (HCV), which affects over 170 million people worldwide and for which current therapeutic options are ineffective. Therefore, we seek: 1) to understand the role of conserved BAAP domains in HCV proteins; and 2) to engineer antiviral peptides that rupture lipid membrane-enveloped HCV particles. The HCV NS5A protein specifically binds the host cell phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) lipid via the BAAP domain structural motif found within its N-terminal amphipathic, alpha-helix (AH). To develop this structural motif—which is also found in other infectious diseases including Malaria, Dengue virus (DV) and Japanese encephalitis virus (JEV)—into a drug target, we will investigate how the PI(4,5)P2:NS5A AH interaction affects the latter binding the critical host cell protein TBC1D20, determine the effect of BAAPP domain mutations on NS5A localization and HCV replication, and develop screens to identify candidate inhibitors of the PI(4,5)P2:NS5A AH interaction. Moreover, we will optimize the chemical sequence of a previously identified antiviral peptide by investigating its ability to lyse lipid vesicles that mimic lipid-enveloped virus particles, determining its virucidal effect on HCV particles, and measuring its potential to reduce HCV infectivity in vitro. To start translating this activity into a clinical application, we will then explore covalent stitching and stapling modifications that preserve the peptide’s properties while increasing its chemical stability. In the long term, the work achieved in this proposal will lay the groundwork for combating a wide range of infectious, viral diseases whose membrane-associated biologic activities make them amenable to our methods.