title: Monoclonal antibodies against extracellular domains of claudin-1 block hepatitis C virus infection in a mouse model.
abstract: Hepatitis C virus (HCV) entry into host cells is a complex process requiring multiple host factors, including claudin-1 (CLDN1). Safe and effective therapeutic entry inhibitors need to be developed. We isolated a human hepatic Huh7.5.1-derived cell mutant that is nonpermissive to HCV, and comparative microarray analysis showed that the mutant was CLDN1 defective. Four hybridomas were obtained, which produced monoclonal antibodies (MAbs) that interacted with the parental Huh7.5.1 cell but not with the CLDN1-defective mutant. All MAbs produced by these hybridomas specifically bound to human CLDN1 with a very high affinity and prevented HCV infection of Huh7.5.1 cells in a dose-dependent manner, without apparent cytotoxicity. Two selected MAbs also inhibited HCV infection of human liver-chimeric mice without significant adverse effects. CLDN1 may be a potential target to prevent HCV infection in vivo. Anti-CLDN1 MAbs may hence be promising candidates as novel anti-HCV agents.
  
  
  OBJECTIVE
  Safe and effective therapeutic entry inhibitors against hepatitis C virus (HCV) are very useful for combination therapies with other anti-HCV drugs, such as direct-acting antivirals. In this study, we first showed an effective strategy for developing functional monoclonal antibodies (MAbs) against extracellular domains of a multimembrane-spanning target protein, claudin-1 (CLDN1), by using parental cells expressing the intact target membrane protein and target-defective cells. The established MAbs against CLDN1, which had a very high affinity for intact CLDN1, efficiently inhibited in vitro and in vivo HCV infections. These anti-CLDN1 MAbs are promising leads for novel entry inhibitors against HCV.
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan fuka@nih.go.jp masuo@phs.osaka-u.ac.jp.
authors: Masayoshi
authors: M
authors: Fukasawa
authors: Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
authors: Shotaro
authors: S
authors: Nagase
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan Graduate School of Biological Science, Tokyo University of Science, Chiba, Japan.
authors: Yoshitaka
authors: Y
authors: Shirasago
authors: Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
authors: Manami
authors: M
authors: Iida
authors: Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
authors: Mayo
authors: M
authors: Yamashita
authors: Life Science Research Laboratories, Wako Pure Chemical Industries, Ltd., Hyogo, Japan.
authors: Kohki
authors: K
authors: Endo
authors: Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
authors: Kiyohito
authors: K
authors: Yagi
authors: Department of Infectious Diseases, Hamamatsu University School of Medicine, Shizuoka, Japan.
authors: Tetsuro
authors: T
authors: Suzuki
authors: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors: Takaji
authors: T
authors: Wakita
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan.
authors: Kentaro
authors: K
authors: Hanada
authors: Department of Molecular Pathology, Nara Medical University, Nara, Japan.
authors: Hiroki
authors: H
authors: Kuniyasu
authors: Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan fuka@nih.go.jp masuo@phs.osaka-u.ac.jp.
authors: Masuo
authors: M
authors: Kondoh
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification / Q000627:therapeutic use; D002460:Cell Line; D062445:Claudin-1 / Q000037:antagonists & inhibitors* / Q000276:immunology; D004195:Disease Models, Animal; D064420:Drug-Related Side Effects and Adverse Reactions; D016174:Hepacivirus / Q000187:drug effects / Q000502:physiology*; D006526:Hepatitis C / Q000517:prevention & control*; D022781:Hepatocytes / Q000821:virology; D006801:Humans; D008297:Male; D051379:Mice; D011991:Receptors, Virus / Q000037:antagonists & inhibitors* / Q000276:immunology; D016896:Treatment Outcome; D053586:Virus Internalization / Q000187:drug effects*
chemical_list: D000911:Antibodies, Monoclonal; C568108:CLDN1 protein, human; D062445:Claudin-1; D011991:Receptors, Virus