title: Productive infection of bovine papillomavirus type 2 in the urothelial cells of naturally occurring urinary bladder tumors in cattle and water buffaloes.
abstract: BACKGROUND
  Papillomaviruses (PVs) are highly epitheliotropic as they usually establish productive infections within squamous epithelia of the skin, the anogenital tract and the oral cavity. In this study, early (E) and late (L) protein expression of bovine papillomavirus type 2 (BPV-2) in the urothelium of the urinary bladder is described in cows and water buffaloes suffering from naturally occurring papillomavirus-associated urothelial bladder tumors.
  
  
  RESULTS
  E5 protein, the major oncoprotein of the BPV-2, was detected in all tumors. L1 DNA was amplified by PCR, cloned and sequenced and confirmed to be L1 DNA. The major capsid protein, L1, believed to be only expressed in productive papillomavirus infection was detected by Western blot analysis. Immunohistochemical investigations confirmed the presence of L1 protein both in the cytoplasm and nuclei of cells of the neoplastic urothelium. Finally, the early protein E2, required for viral DNA replication and known to be a pivotal factor for both productive and persistent infection, was detected by Western blot and immunohistochemically. Electron microscopic investigations detected electron dense particles, the shape and size of which are consistent with submicroscopic features of viral particles, in nuclei of neoplastic urothelium.
  
  
  CONCLUSIONS
  This study shows that both active and productive infections by BPV-2 in the urothelium of the bovine and bubaline urinary bladder can occur in vivo.
authors.affiliation: Dipartimento di Medicina Veterinaria e Produzioni Animali, Sezione Malattie Infettive, Università di Napoli Federico II, Naples, Italy. sante.roperto@unina.it
authors.forename: Sante
authors.initials: S
authors.lastname: Roperto
authors.forename: Valeria
authors.initials: V
authors.lastname: Russo
authors.forename: Ayhan
authors.initials: A
authors.lastname: Ozkul
authors.forename: Annunziata
authors.initials: A
authors.lastname: Corteggio
authors.forename: Aylin
authors.initials: A
authors.lastname: Sepici-Dincel
authors.forename: Cornel
authors.initials: C
authors.lastname: Catoi
authors.forename: Iolanda
authors.initials: I
authors.lastname: Esposito
authors.forename: Marita G
authors.initials: MG
authors.lastname: Riccardi
authors.forename: Chiara
authors.initials: C
authors.lastname: Urraro
authors.forename: Roberta
authors.initials: R
authors.lastname: Lucà
authors.forename: Dora M
authors.initials: DM
authors.lastname: Ceccarelli
authors.forename: Michele
authors.initials: M
authors.lastname: Longo
authors.forename: Franco
authors.initials: F
authors.lastname: Roperto
mesh_terms: D000818:Animals; D001483:Base Sequence; D052688:Bovine papillomavirus 1 / Q000235:genetics / Q000502:physiology*; D002020:Buffaloes / Q000821:virology*; D036022:Capsid Proteins / Q000235:genetics; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology* / Q000821:virology*; D008969:Molecular Sequence Data; D001749:Urinary Bladder Neoplasms / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D019459:Urothelium / Q000473:pathology* / Q000821:virology*
chemical_list: D036022:Capsid Proteins; C085217:L1 protein, Bovine papillomavirus