Development of Highly Efficient Vi Ral Pseudoparticle Platform for the Identification of Novel Hepatitis C Vi Rus Entry Inhibitors

Without a preventive vaccine, hepatitis C virus (HCV) remains an important pathogen worldwide with 170-300 millions of carriers at risk of end-stage liver diseases. Despite the introduction of novel direct acting antivirals (DAAs), resistance problems, challenges with the difficult-to-treat populations, and high cost limit the widespread application of these drugs. Importantly, addressing DAA failures due to resistance problems is becoming an apparent issue with increasing treatment in the real world populations. Antivirals with alternate mechanism of action, such as by restricting viral entry could help expand the scope of antiviral strategies to improve the management of hepatitis C. Thus far, no FDA-approved entry inhibitor exists against HCV. Viral pseudoparticles expressing HCV glycoproteins (HCVpp) represent a drug discovery tool and a specific approach to identifying entry inhibitors against HCV. Our goal in this 3-year study is to develop a highly efficient HCVpp-based antiviral screening platform for the identification of novel HCV entry inhibitors. Specifically, in Year 1, we establish a high titer reporter-tagged HCVpp system as a high-throughput antiviral screening platform and identify potential candidate HCV entry inhibitors using a panel of small molecules. In Year 2, we confirm the mechanism specificity of these candidate inhibitors by dissecting the HCV early viral entry steps (particle inactivation, receptor attachment, post-binding entry/fusion) as well as performing molecular docking on the viral glycoproteins to identify the potential target(s). Finally, in Year 3, we explore the clinical applicability of these inhibitors by validating their antiviral efficacy in primary human hepatocytes, determining their pan-genotypic activity, examining their broad-spectrum antiviral capability against other viruses, and investigate the possibility of combinatorial treatment with other HCV DAAs. Altogether, these analyses will help establish a highly instrumental HCVpp-based drug discovery system and identify novel entry inhibitors for next generation prophylactic/therapeutic management of hepatitis C.