title: IFNL3 genotype is associated with differential induction of IFNL3 in primary human hepatocytes.
abstract: BACKGROUND
  Lambda interferons (IFNLs) have potent antiviral activity against HCV, and polymorphisms within the IFNL gene cluster near the IFNL3 gene strongly predict spontaneous- and treatment-related HCV infection outcomes. The mechanism(s) linking IFNL polymorphisms and HCV control is currently elusive.
  
  
  METHODS
  IFNL induction was studied in primary human hepatocytes (PHH) from 18 human donors, peripheral blood mononuclear cells (PBMCs) from 18 human donors, multiple cell lines and induced pluripotent stem cell-derived hepatocyte-like cells (iPSC-hepatocytes) from 7 human donors. After stimulation with intracellular RNA and infectious HCV, quantitative PCR (qPCR) primers and probes were designed to distinguish and quantify closely related IFNL messenger (m)RNAs from IFNL1, IFNL2 and IFNL3.
  
  
  RESULTS
  PHH demonstrated the most potent induction of IFNLs, although had lower pre-stimulation levels compared to PBMCs, monocytes and cell lines. PHH stimulation with cytoplasmic poly I:C induced >1,000-fold expression of IFNL1, IFNL2 and IFNL3. PHH from donors who were homozygous for the favourable IFNL3 allele (IFNL3-CC) had higher IFNL3 induction compared to PHH from IFNL3-TT donors (P=0.03). Baseline IFNL mRNA expression and induction was also tested in iPSC-hepatocytes: iPSC-hepatocytes had significantly higher baseline expression of IFNLs compared to PHH (P<0.0001), and IFNL3 induction was marginally different in iPSC-hepatocytes by IFNL genotype (P=0.07).
  
  
  CONCLUSIONS
  Hepatocytes express IFNLs when stimulated by a synthetic viral RNA that signals the cell through the cytoplasm. IFNL induction may be greater in persons with the favourable IFNL3 allele. These data provide insight into the strong linkage between IFNL3 genetics and control of HCV infection.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.
authors.forename: Fuat
authors.initials: F
authors.lastname: Kurbanov
authors.forename: Yonghak
authors.initials: Y
authors.lastname: Kim
authors.forename: Rachel
authors.initials: R
authors.lastname: Latanich
authors.forename: Pooja
authors.initials: P
authors.lastname: Chaudhari
authors.forename: Ramy
authors.initials: R
authors.lastname: El-Diwany
authors.forename: Matt
authors.initials: M
authors.lastname: Knabel
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Kandathil
authors.forename: Andrew
authors.initials: A
authors.lastname: Cameron
authors.forename: Andrea
authors.initials: A
authors.lastname: Cox
authors.forename: Yoon-Young
authors.initials: YY
authors.lastname: Jang
authors.forename: David L
authors.initials: DL
authors.lastname: Thomas
authors.forename: Ashwin
authors.initials: A
authors.lastname: Balagopal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002460:Cell Line; D002648:Child; D005260:Female; D005786:Gene Expression Regulation; D005838:Genotype; D016174:Hepacivirus; D006526:Hepatitis C / Q000235:genetics / Q000378:metabolism / Q000821:virology; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D007372:Interferons; D007378:Interleukins / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D055815:Young Adult; D000095022:Interferon Lambda
chemical_list: D007372:Interferons; D007378:Interleukins; D012333:RNA, Messenger; C000624353:interferon-lambda, human; D000095022:Interferon Lambda; C579163:IFNL4 protein, human