title: Hepatocytes that express variants of cyclophilin A are resistant to HCV infection and replication.
abstract: OBJECTIVE
  Hepatitis C virus (HCV) uses several host factors to infect and replicate in human hepatocytes. Cyclophilin A (CypA) is required for viral replication, and CypA inhibitors are in development. We investigated the effects of nonsynonymous single nucleotide polymorphisms (SNPs) in the region of peptidyl-prolyl isomerase A (PPIA) that encodes CypA on HCV infection and replication of human hepatocytes.
  
  
  METHODS
  We used a combination of virologic, biochemical, and genetic approaches to investigate the effects of PPIA variants on HCV replication in cultured Huh-7.5 cells. We reduced levels of CypA in these cells using small hairpin RNAs (shRNAs).
  
  
  RESULTS
  Using shRNAs, we showed that CypA was required for replication of HCV in Huh-7.5 cells and identified 3 SNPs in PPIA that protected cells from HCV entry or replication. Levels of HCV RNA were reduced 3-4 log in cells homozygous for the variant alleles; release of new particles was also reduced, but viral entry was not affected. The effects of the variant alleles were recessive and stronger for preventing replication of full-length HCV genomes than subgenomes. CypA inhibitors prevented replication of residual HCV in hepatocytes. The variants appeared to destabilize the CypA protein; the single amino acid changes led to rapid degradation of the protein.
  
  
  CONCLUSIONS
  We identified variants in PPIA that destabilize its product, CypA, and prevent HCV infection and replication. These findings indicate mechanisms by which some cells might be resistant to HCV infection and that CypA is a good therapeutic target.
authors.affiliation: Medizinische Hochschule Hannover, Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: von Hahn
authors.forename: Cordelia
authors.initials: C
authors.lastname: Schiene-Fischer
authors.forename: Nguyen Dinh
authors.initials: ND
authors.lastname: Van
authors.forename: Stephanie
authors.initials: S
authors.lastname: Pfaender
authors.forename: Behya
authors.initials: B
authors.lastname: Karavul
authors.forename: Eike
authors.initials: E
authors.lastname: Steinmann
authors.forename: Andrej
authors.initials: A
authors.lastname: Potthoff
authors.forename: Christian
authors.initials: C
authors.lastname: Strassburg
authors.forename: Nabila
authors.initials: N
authors.lastname: Hamdi
authors.forename: Ahmed I
authors.initials: AI
authors.lastname: Abdelaziz
authors.forename: Christoph
authors.initials: C
authors.lastname: Sarrazin
authors.forename: Tobias
authors.initials: T
authors.lastname: Müller
authors.forename: Thomas
authors.initials: T
authors.lastname: Berg
authors.forename: Eric
authors.initials: E
authors.lastname: Trépo
authors.forename: Heiner
authors.initials: H
authors.lastname: Wedemeyer
authors.forename: Michael P
authors.initials: MP
authors.lastname: Manns
authors.forename: Thomas
authors.initials: T
authors.lastname: Pietschmann
authors.forename: Sandra
authors.initials: S
authors.lastname: Ciesek
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D045744:Cell Line, Tumor; D021984:Cyclophilin A / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D016174:Hepacivirus / Q000502:physiology*; D006526:Hepatitis C / Q000821:virology*; D022781:Hepatocytes / Q000378:metabolism / Q000821:virology*; D006801:Humans; D015151:Immunoblotting; D020641:Polymorphism, Single Nucleotide; D053586:Virus Internalization; D014779:Virus Replication
chemical_list: D015415:Biomarkers; D021984:Cyclophilin A