Dominic H Banda1, Paula M Perin1, Richard J P Brown1, Daniel Todt2, Wladimir Solodenko3, Patrick Hoffmeyer3, Kamlesh Kumar Sahu4, Michael Houghton4, Philip Meuleman5, Rolf Müller6, Andreas Kirschning3, Thomas Pietschmann7. 1. Institute of Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Feodor-Lynen-Str. 7, 30625 Hannover, Germany. 2. Institute of Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Feodor-Lynen-Str. 7, 30625 Hannover, Germany; Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany. 3. Institute of Organic Chemistry and Center of Biomolecular Drug Research (BMWZ), Leibniz Universität, Hannover, Germany. 4. Li Ka Shing Institute of Virology, Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada. 5. Laboratory of Liver Infectious Diseases, Ghent University, Ghent, Belgium. 6. Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken, Germany. 7. Institute of Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Feodor-Lynen-Str. 7, 30625 Hannover, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 30625 Hannover, Germany. Electronic address: thomas.pietschmann@twincore.de.
Abstract
BACKGROUND & AIMS: Hepatitis C virus (HCV) infection causes chronic liver disease. Antivirals have been developed and cure infection. However, resistance can emerge and salvage therapies with alternative modes of action could be useful. Several licensed drugs have emerged as HCV entry inhibitors and are thus candidates for drug repurposing. We aimed to dissect their mode of action, identify improved derivatives and determine their viral targets. METHODS: HCV entry inhibition was tested for a panel of structurally related compounds, using chimeric viruses representing diverse genotypes, in addition to viruses containing previously determined resistance mutations. Chemical modeling and synthesis identified improved derivatives, while generation of susceptible and non-susceptible chimeric viruses pinpointed E1 determinants of compound sensitivity. RESULTS: Molecules of the diphenylpiperazine, diphenylpiperidine, phenothiazine, thioxanthene, and cycloheptenepiperidine chemotypes inhibit HCV infection by interfering with membrane fusion. These molecules and a novel p-methoxy-flunarizine derivative with improved efficacy preferentially inhibit genotype 2 viral strains. Viral residues within a central hydrophobic region of E1 (residues 290-312) control susceptibility. At the same time, viral features in this region also govern pH-dependence of viral membrane fusion. CONCLUSIONS: Small molecules from different chemotypes related to flunarizine preferentially inhibit HCV genotype 2 membrane fusion. A hydrophobic region proximal to the putative fusion loop controls sensitivity to these drugs and the pH range of membrane fusion. An algorithm considering viral features in this region predicts viral sensitivity to membrane fusion inhibitors. Resistance to flunarizine correlates with more relaxed pH requirements for fusion. LAY SUMMARY: This study describes diverse compounds that act as HCV membrane fusion inhibitors. It defines viral properties that determine sensitivity to these molecules and thus provides information to identify patients that may benefit from treatment with membrane fusion inhibitors.
BACKGROUND & AIMS:Hepatitis C virus (HCV) infection causes chronic liver disease. Antivirals have been developed and cure infection. However, resistance can emerge and salvage therapies with alternative modes of action could be useful. Several licensed drugs have emerged as HCV entry inhibitors and are thus candidates for drug repurposing. We aimed to dissect their mode of action, identify improved derivatives and determine their viral targets. METHODS:HCV entry inhibition was tested for a panel of structurally related compounds, using chimeric viruses representing diverse genotypes, in addition to viruses containing previously determined resistance mutations. Chemical modeling and synthesis identified improved derivatives, while generation of susceptible and non-susceptible chimeric viruses pinpointed E1 determinants of compound sensitivity. RESULTS: Molecules of the diphenylpiperazine, diphenylpiperidine, phenothiazine, thioxanthene, and cycloheptenepiperidine chemotypes inhibit HCV infection by interfering with membrane fusion. These molecules and a novel p-methoxy-flunarizine derivative with improved efficacy preferentially inhibit genotype 2 viral strains. Viral residues within a central hydrophobic region of E1 (residues 290-312) control susceptibility. At the same time, viral features in this region also govern pH-dependence of viral membrane fusion. CONCLUSIONS: Small molecules from different chemotypes related to flunarizine preferentially inhibit HCV genotype 2 membrane fusion. A hydrophobic region proximal to the putative fusion loop controls sensitivity to these drugs and the pH range of membrane fusion. An algorithm considering viral features in this region predicts viral sensitivity to membrane fusion inhibitors. Resistance to flunarizine correlates with more relaxed pH requirements for fusion. LAY SUMMARY: This study describes diverse compounds that act as HCV membrane fusion inhibitors. It defines viral properties that determine sensitivity to these molecules and thus provides information to identify patients that may benefit from treatment with membrane fusion inhibitors.
Authors: Antonia P Gunesch; Francisco J Zapatero-Belinchón; Lukas Pinkert; Eike Steinmann; Michael P Manns; Gisbert Schneider; Thomas Pietschmann; Mark Brönstrup; Thomas von Hahn Journal: Antimicrob Agents Chemother Date: 2020-07-22 Impact factor: 5.191
Authors: Jennifer M Pfaff-Kilgore; Edgar Davidson; Kathryn Kadash-Edmondson; Mayda Hernandez; Erin Rosenberg; Ross Chambers; Matteo Castelli; Nicola Clementi; Nicasio Mancini; Justin R Bailey; James E Crowe; Mansun Law; Benjamin J Doranz Journal: Cell Rep Date: 2022-05-24 Impact factor: 9.995