title: Analysis of human adenovirus type 19 associated with epidemic keratoconjunctivitis and its reclassification as adenovirus type 64.
abstract: OBJECTIVE
  Human adenovirus species D type 19 (HAdV-D19) has been associated with epidemic keratoconjunctivitis (EKC), a highly inflammatory infection of the ocular surface. Confusion exists regarding the origins of HAdV-D19. The prototype virus (HAdV-D19p) does not cause EKC, while a virus identified later with the identical serologic determinant is a significant ocular pathogen.
  
  
  METHODS
  High throughput genome sequencing and bioinformatics analysis were performed on HAdV-D19p and three HAdV-D19 EKC strains, and compared to the previously sequenced clinical isolate, HAdV-D19 (C) and HAdV-D37. Corneas of C57BL/6J mice were injected with HAdV-D19p, HAdV-D19 (C), or virus-free buffer, and inflammation assessed by clinical examination, flow cytometry, and cytokine ELISA. Confocal microscopy and real-time PCR of infected corneal cell cultures were used to test viral entry.
  
  
  RESULTS
  HAdV-D19 (C) and the other clinical EKC isolates showed nearly 100% sequence identity. EKC strains diverged from HAdV-D19p in the penton base, E3, and fiber transcription units. Simplot analysis showed recombination between EKC-associated HAdV-D19 with HAdV-D37, HAdV-D22, and HAdV-D19p, the latter contributing only the hexon gene, the principal serum neutralization determinant. HAdV-D19p induced stromal keratitis in the C57BL/6J mouse, but failed to infect productively human corneal epithelial cells. These data led to retyping of the clinical EKC isolates with a HAdV-D19 hexon gene as HAdV-D64.
  
  
  CONCLUSIONS
  HAdV-D19 associated with EKC (HAdV-D64) originated from a recombination between HAdV-D19p, HAdV-D37, and HAdV-D22, and was mischaracterized because of a shared hexon gene. HAdV-D19p is not infectious for corneal epithelial cells, thus explaining the lack of any association with keratitis.
authors.affiliation: Department of Ophthalmology, Howe Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Zhou
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Robinson
authors.forename: Jaya
authors.initials: J
authors.lastname: Rajaiya
authors.forename: Shoaleh
authors.initials: S
authors.lastname: Dehghan
authors.forename: Donald
authors.initials: D
authors.lastname: Seto
authors.forename: Morris S
authors.initials: MS
authors.lastname: Jones
authors.forename: David W
authors.initials: DW
authors.lastname: Dyer
authors.forename: James
authors.initials: J
authors.lastname: Chodosh
mesh_terms: D000258:Adenovirus Infections, Human / Q000821:virology*; D000260:Adenoviruses, Human / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D000818:Animals; D004279:DNA, Viral / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D016679:Genome, Viral; D006801:Humans; D007637:Keratoconjunctivitis / Q000821:virology*; D051379:Mice; D008810:Mice, Inbred C57BL; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral