title: Activation of checkpoint kinase 2 is critical for herpes simplex virus type 1 replication in corneal epithelium.
abstract: OBJECTIVE
  Herpes simplex virus (HSV) type I keratitis remains a leading cause of corneal morbidity, despite the availability of effective antiviral drugs. Improved understanding of virus-host interactions at the level of the host DNA damage response (DDR), a known factor in the development of HSV-1 keratitis, may shed light on potential new therapeutic targets. This report examines the role of checkpoint kinase 2 (Chk2), a DDR mediator protein, in corneal epithelial HSV-1 infection.
  
  
  METHODS
  A small-molecule inhibitor of Chk2 (Chk2 inhibitor II) was applied to HSV-1-infected cultured human corneal epithelial cells (hTCEpi and HCE) as well as to explanted and organotypically cultured human and rabbit corneas. Infection levels were assessed by plaque assay and real-time PCR. RNAi-mediated depletion of Chk2 was performed to confirm the effect of the inhibitor.
  
  
  RESULTS
  Inhibition of the Chk2 kinase activity greatly suppresses the cytopathic effect, genome replication and infectious progeny production in vitro and ex vivo.
  
  
  CONCLUSIONS
  This report demonstrates the critical role of Chk2 kinase in the establishment of HSV-1 corneal epithelial infection. These data contribute to our understanding of herpesvirus-host interactions and underscore the significance of DDR activation in HSV-1 keratitis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pa., USA.
authors.forename: Oleg
authors.initials: O
authors.lastname: Alekseev
authors.forename: Vladimir
authors.initials: V
authors.lastname: Limonnik
authors.forename: Kelly
authors.initials: K
authors.lastname: Donovan
authors.forename: Jane
authors.initials: J
authors.lastname: Azizkhan-Clifford
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D064447:Checkpoint Kinase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003588:Cytopathogenic Effect, Viral; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019573:Epithelium, Corneal / Q000187:drug effects / Q000821:virology*; D019084:Fluorescent Antibody Technique, Indirect; D018259:Herpesvirus 1, Human / Q000502:physiology*; D006801:Humans; D016849:Keratitis, Herpetic / Q000201:enzymology / Q000821:virology*; D009924:Organ Culture Techniques; D010766:Phosphorylation; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D014779:Virus Replication
chemical_list: D004791:Enzyme Inhibitors; D064447:Checkpoint Kinase 2