title: A functional genomic screen reveals novel host genes that mediate interferon-alpha's effects against hepatitis C virus.
abstract: OBJECTIVE
  The precise mechanisms by which IFN exerts its antiviral effect against HCV have not yet been elucidated. We sought to identify host genes that mediate the antiviral effect of IFN-α by conducting a whole-genome siRNA library screen.
  
  
  METHODS
  High throughput screening was performed using an HCV genotype 1b replicon, pRep-Feo. Those pools with replicate robust Z scores ≥2.0 entered secondary validation in full-length OR6 replicon cells. Huh7.5.1 cells infected with JFH1 were then used to validate the rescue efficacy of selected genes for HCV replication under IFN-α treatment.
  
  
  RESULTS
  We identified and confirmed 93 human genes involved in the IFN-α anti-HCV effect using a whole-genome siRNA library. Gene ontology analysis revealed that mRNA processing (23 genes, p=2.756e-22), translation initiation (nine genes, p=2.42e-6), and IFN signaling (five genes, p=1.00e-3) were the most enriched functional groups. Nine genes were components of U4/U6.U5 tri-snRNP. We confirmed that silencing squamous cell carcinoma antigen recognized by T cells (SART1), a specific factor of tri-snRNP, abrogates IFN-α's suppressive effects against HCV in both replicon cells and JFH1 infectious cells. We further found that SART1 was not IFN-α inducible, and its anti-HCV effector in the JFH1 infectious model was through regulation of interferon stimulated genes (ISGs) with or without IFN-α.
  
  
  CONCLUSIONS
  We identified 93 genes that mediate the anti-HCV effect of IFN-α through genome-wide siRNA screening; 23 and nine genes were involved in mRNA processing and translation initiation, respectively. These findings reveal an unexpected role for mRNA processing in generation of the antiviral state, and suggest a new avenue for therapeutic development in HCV.
authors: Department of Infectious Diseases, Peking University First Hospital, Beijing 100034, China.
authors: Hong
authors: H
authors: Zhao
authors: Wenyu
authors: W
authors: Lin
authors: Kattareeya
authors: K
authors: Kumthip
authors: Du
authors: D
authors: Cheng
authors: Dahlene N
authors: DN
authors: Fusco
authors: Oliver
authors: O
authors: Hofmann
authors: Nikolaus
authors: N
authors: Jilg
authors: Andrew W
authors: AW
authors: Tai
authors: Kaku
authors: K
authors: Goto
authors: Leiliang
authors: L
authors: Zhang
authors: Winston
authors: W
authors: Hide
authors: Jae Young
authors: JY
authors: Jang
authors: Lee F
authors: LF
authors: Peng
authors: Raymond T
authors: RT
authors: Chung
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D019295:Computational Biology; D015894:Genome, Human; D023281:Genomics; D016174:Hepacivirus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000235:genetics* / Q000821:virology; D057166:High-Throughput Screening Assays; D054884:Host-Pathogen Interactions / Q000235:genetics*; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology*; D010597:Pharmacogenetics; D034741:RNA, Small Interfering / Q000235:genetics; D053633:Receptor, Interferon alpha-beta / Q000235:genetics; D012093:Replicon; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics
chemical_list: D000951:Antigens, Neoplasm; D000998:Antiviral Agents; C507964:IFNAR1 protein, human; D016898:Interferon-alpha; D034741:RNA, Small Interfering; D017411:Ribonucleoproteins, Small Nuclear; C431323:SART1 protein, human; D053633:Receptor, Interferon alpha-beta