title: Cyclosporin derivatives inhibit hepatitis B virus entry without interfering with NTCP transporter activity.
abstract: The sodium taurocholate co-transporting polypeptide (NTCP) is the main target of most hepatitis B virus (HBV) specific entry inhibitors. Unfortunately, these agents also block NTCP transport of bile acids into hepatocytes, and thus have the potential to cause adverse effects. We aimed to identify small molecules that inhibit HBV entry while maintaining NTCP transporter function.
  
  
  
  We characterized a series of cyclosporine (CsA) derivatives for their anti-HBV activity and NTCP binding specificity using HepG2 cells overexpressing NTCP and primary human hepatocytes. The four most potent derivatives were tested for their capacity to prevent HBV entry, but maintain NTCP transporter function. Their antiviral activity against different HBV genotypes was analysed.
  
  
  
  We identified several CsA derivatives that inhibited HBV infection with a sub-micromolar IC50. Among them, SCY446 and SCY450 showed low activity against calcineurin (CN) and cyclophilins (CyPs), two major CsA cellular targets. This suggested that instead, these compounds interacted directly with NTCP to inhibit viral attachment to host cells, and have no immunosuppressive function. Importantly, we found that SCY450 and SCY995 did not impair the NTCP-dependent uptake of bile acids, and inhibited multiple HBV genotypes including a clinically relevant nucleoside analog-resistant HBV isolate.
  
  
  
  This is the first example of small molecule selective inhibition of HBV entry with no decrease in NTCP transporter activity. It suggests that the anti-HBV activity can be functionally separated from bile acid transport. These broadly active anti-HBV molecules are potential candidates for developing new drugs with fewer adverse effects.
  
  
  
  In this study, we identified new compounds that selectively inhibited hepatitis B virus (HBV) entry, and did not impair bile acid uptake. Our evidence offers a new strategy for developing anti-HBV drugs with fewer side effects.
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan; SCYNEXIS, Inc., Durham, NC 27713, USA.
authors.forename: Satomi
authors.initials: S
authors.lastname: Shimura
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan; Department of Applied Biological Science, Tokyo University of Sciences, Noda 278-8510, Japan; CREST, Japan Science and Technology Agency (J.S.T.), Saitama 332-0012, Japan. Electronic address: kwatashi@nih.go.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Watashi
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan; Department of Analytical Biochemistry, Meiji Pharmaceutical University, Kiyose 204-8588, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Fukano
authors.affiliation: SCYNEXIS, Inc., Durham, NC 27713, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Peel
authors.affiliation: SCYNEXIS, Inc., Durham, NC 27713, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: Sluder
authors.affiliation: Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan.
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Kawai
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan; Department of Applied Biological Science, Tokyo University of Sciences, Noda 278-8510, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Iwamoto
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan; Micro-signaling Regulation Technology Unit, RIKEN Center for Life Science Technologies, Wako 351-0198, Japan.
authors.forename: Senko
authors.initials: S
authors.lastname: Tsukuda
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
authors.forename: Junko S
authors.initials: JS
authors.lastname: Takeuchi
authors.affiliation: The University of Tokyo, Graduate School of Pharmaceutical Sciences, Tokyo 113-0033, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyake
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa 272-8516, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Sugiyama
authors.affiliation: Department of Analytical Biochemistry, Meiji Pharmaceutical University, Kiyose 204-8588, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ogasawara
authors.affiliation: Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan.
authors.forename: Sam-Yong
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Virology and Liver Unit, Nagoya City University Graduate School of Medicinal Sciences, Nagoya 467-8601, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: The University of Tokyo, Graduate School of Pharmaceutical Sciences, Tokyo 113-0033, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusuhara
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa 272-8516, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
authors.affiliation: Laboratoire de Virologie Moléculaire, Institut National de la Transfusion Sanguine (INTS), Paris, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Sureau
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
authors.forename: Takaji
authors.initials: T
authors.lastname: Wakita
mesh_terms: D000998:Antiviral Agents / Q000009:adverse effects / Q000494:pharmacology; D001647:Bile Acids and Salts / Q000378:metabolism; D002478:Cells, Cultured; D003524:Cyclosporins / Q000009:adverse effects / Q000494:pharmacology*; D056945:Hep G2 Cells; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D003698:Hepatitis Delta Virus / Q000187:drug effects / Q000502:physiology; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism / Q000821:virology; D006801:Humans; D029363:Organic Anion Transporters, Sodium-Dependent / Q000378:metabolism*; D027981:Symporters / Q000378:metabolism*; D053586:Virus Internalization / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D001647:Bile Acids and Salts; D003524:Cyclosporins; D029363:Organic Anion Transporters, Sodium-Dependent; D027981:Symporters; C071908:sodium-bile acid cotransporter
keywords: Antiviral; Bile acids and salts; Cyclophilins; Cyclosporine; HBV; Hepatitis B virus; Hepatitis D virus; Infection; Membrane transport proteins; NTCP; PreS1; Replication