title: Cell entry, efficient RNA replication, and production of infectious hepatitis C virus progeny in mouse liver-derived cells.
abstract: Only humans and chimpanzees are susceptible to chronic infection by hepatitis C virus (HCV). The restricted species tropism of HCV is determined by distinct host factor requirements at different steps of the viral life cycle. In addition, effective innate immune targeting precludes efficient propagation of HCV in nonhuman cells. Species-specificity of HCV host factor usage for cell entry and virus release has been explored. However, the reason for inefficient HCV RNA replication efficiency in mouse liver cells remains elusive. To address this, we generated novel mouse liver-derived cell lines with specific lesions in mitochondrial antiviral signaling protein (MAVS), interferon regulatory factor 3 (IRF3), or Interferon-α/β receptor (IFNAR) by in vivo immortalization. Blunted innate immune responses in these cells modestly increased HCV RNA replication. However, ectopic expression of liver-specific human microRNA 122 (miR-122) further boosted RNA replication in all knockout cell lines. Remarkably, MAVS(-/-) miR-122 cells sustained vigorous HCV RNA replication, attaining levels comparable to the highly permissive human hepatoma cell line Huh-7.5. RNA replication was dependent on mouse cyclophilin and phosphatidylinositol-4 kinase III alpha (PI4KIIIα) and was also observed after transfection of full-length viral RNA. Additionally, ectopic expression of either human or mouse apolipoprotein E (ApoE) was sufficient to permit release of infectious particles. Finally, expression of human entry cofactors rendered these cells permissive to HCV infection, thus confirming that all steps of the HCV replication cycle can be reconstituted in mouse liver-derived cells.
  
  
  CONCLUSIONS
  Blunted innate immunity, abundant miR-122, and HCV entry factor expression permits propagation of HCV in mouse liver-derived cell lines.
authors.affiliation: Institute of Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Frentzen
authors.lastname: Anggakusuma
authors.forename: Engin
authors.initials: E
authors.lastname: Gürlevik
authors.forename: Kathrin
authors.initials: K
authors.lastname: Hueging
authors.forename: Sarah
authors.initials: S
authors.lastname: Knocke
authors.forename: Corinne
authors.initials: C
authors.lastname: Ginkel
authors.forename: Richard J P
authors.initials: RJ
authors.lastname: Brown
authors.forename: Markus
authors.initials: M
authors.lastname: Heim
authors.forename: Michael T
authors.initials: MT
authors.lastname: Dill
authors.forename: Andrea
authors.initials: A
authors.lastname: Kröger
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kalinke
authors.forename: Lars
authors.initials: L
authors.lastname: Kaderali
authors.forename: Florian
authors.initials: F
authors.lastname: Kuehnel
authors.forename: Thomas
authors.initials: T
authors.lastname: Pietschmann
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D001057:Apolipoproteins E / Q000378:metabolism; D045744:Cell Line, Tumor; D021983:Cyclophilins / Q000378:metabolism; D016174:Hepacivirus / Q000502:physiology*; D006801:Humans; D007113:Immunity, Innate; D008099:Liver / Q000821:virology; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D053586:Virus Internalization; D014779:Virus Replication
chemical_list: D019870:1-Phosphatidylinositol 4-Kinase; D048868:Adaptor Proteins, Signal Transducing; D001057:Apolipoproteins E; D021983:Cyclophilins; D035683:MicroRNAs; D012367:RNA, Viral; C512612:MAVS protein, mouse; C544354:Mirn122 microRNA, mouse