Slim Fourati, Muriel Gelin, Quentin Nevers, Rozenn Brillet, Camille Baudesson, Patrice Bruscella, Isaac Ruiz, Maxime Chazal, Flora Donati, Nolwenn Jouvenet, Laurent Softic, Jean-François Guichou, Abdelhakim Ahmed-Belkacem, Nazim Ahnou, Jean-Michel Pawlotsky, Institut Mondor de Recherche Biomédicale (IMRB), Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR10-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Centre National de Référence Virus des hépatites B, C et Delta, Institut National de la Transfusion Sanguine [Paris] (INTS)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Génomique virale et vaccination, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Centre de Biochimie Structurale [Montpellier] (CBS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), Q.N. received a predoctoral fellowship grant from the French Ministry for Research. I.R. received predoctoral fellowship grants from the National Agency for Research on AIDS and Viral Hepatitis (ANRS) and the Mexican National Council on Science and Technology (CONACYT). This work was partly supported by French Infrastructure for Integrated Structural Biology (FRISBI) grant ANR-10-INBS-05., We are grateful to Nathalie Pardigon (Institut Pasteur, France), Cécile Khou (Institut Pasteur, France), and Justine Basset (Institut Pasteur, France) for their help with WNV and JEV experiments. We are grateful to Charles M. Rice (Rockefeller University, New York, NY, USA), Ralf Bartenschlager (University of Heidelberg, Germany), Jens Bukh (University of Copenhagen, Denmark), and Takaji Wakita (National Institute for Infectious Diseases, Tokyo, Japan) for kindly providing plasmids., ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Although members of the Flaviviridae display high incidence, morbidity, and mortality rates, the development of specific antiviral drugs for each virus is unlikely. Cyclophilins, a family of host peptidyl-prolyl cis-trans isomerases (PPIases), play a pivotal role in the life cycles of many viruses and therefore represent an attractive target for broad-spectrum antiviral development. We report here the pangenotypic anti-hepatitis C virus (HCV) activity of a small-molecule cyclophilin inhibitor (SMCypI). Mechanistic and modeling studies revealed that the SMCypI bound to cyclophilin A in competition with cyclosporine (CsA), inhibited its PPIase activity, and disrupted the CypA-nonstructural protein 5A (NS5A) interaction. Resistance selection showed that the lead SMCypI hardly selected amino acid substitutions conferring low-level or no resistance in vitro . Interestingly, the SMCypI selected D320E and Y321H substitutions, located in domain II of the NS5A protein. These substitutions were previously associated with low-level resistance to cyclophilin inhibitors such as alisporivir. Finally, the SMCypI inhibited the replication of other members of the Flaviviridae family with higher 50% effective concentrations (EC 50 s) than for HCV. Thus, because of its chemical plasticity and simplicity of synthesis, our new family of SMCypIs represents a promising new class of drugs with the potential for broad-spectrum anti- Flaviviridae activity as well as an invaluable tool to explore the role of cyclophilins in viral life cycles.