title: Feline panleukopenia virus in cerebral neurons of young and adult cats.
abstract: BACKGROUND
  Perinatal infections with feline panleukopenia virus (FPV) have long been known to be associated with cerebellar hypoplasia in kittens due to productive infection of dividing neuroblasts. FPV, like other parvoviruses, requires dividing cells to replicate which explains the usual tropism of the virus for the digestive tract, lymphoid tissues and bone marrow in older animals.
  
  
  RESULTS
  In this study, the necropsy and histopathological analyses of a series of 28 cats which died from parvovirus infection in 2013 were performed. Infections were confirmed by real time PCR and immunohistochemistry in several organs. Strikingly, while none of these cats showed cerebellar atrophy or cerebellar positive immunostaining, some of them, including one adult, showed a bright positive immunostaining for viral antigens in cerebral neurons (diencephalon). Furthermore, infected neurons were negative by immunostaining for p27(Kip1), a cell cycle regulatory protein, while neighboring, uninfected, neurons were positive, suggesting a possible re-entry of infected neurons into the mitotic cycle. Next-Generation Sequencing and PCR analyses showed that the virus infecting cat brains was FPV and presented a unique substitution in NS1 protein sequence. Given the role played by this protein in the control of cell cycle and apoptosis in other parvoviral species, it is tempting to hypothesize that a cause-to-effect between this NS1 mutation and the capacity of this FPV strain to infect neurons in adult cats might exist.
  
  
  CONCLUSIONS
  This study provides the first evidence of infection of cerebral neurons by feline panleukopenia virus in cats, including an adult. A possible re-entry into the cell cycle by infected neurons has been observed. A mutation in the NS1 protein sequence of the FPV strain involved could be related to its unusual cellular tropism. Further research is needed to clarify this point.
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. mmgarigliany@ulg.ac.be.
authors.forename: Mutien
authors.initials: M
authors.lastname: Garigliany
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. ggilliaux@ulg.ac.be.
authors.forename: Gautier
authors.initials: G
authors.lastname: Gilliaux
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. sandra.jolly@ulg.ac.be.
authors.forename: Sandra
authors.initials: S
authors.lastname: Jolly
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. trcasanova@doct.ulg.ac.be.
authors.forename: Tomas
authors.initials: T
authors.lastname: Casanova
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. calixte.bayrou@ulg.ac.be.
authors.forename: Calixte
authors.initials: C
authors.lastname: Bayrou
authors.affiliation: Department of Clinical Sciences, University of Liège, Liège, Belgium. kris.gommeren@ulg.ac.be.
authors.forename: Kris
authors.initials: K
authors.lastname: Gommeren
authors.affiliation: Department of Infectious and Parasitic Diseases, Centre for Fundamental and Applied Research for Animals & Health, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium. thomas.fett@ulg.ac.be.
authors.forename: Thomas
authors.initials: T
authors.lastname: Fett
authors.affiliation: Department of Infectious and Parasitic Diseases, Centre for Fundamental and Applied Research for Animals & Health, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium. amauroy@ulg.ac.be.
authors.forename: Axel
authors.initials: A
authors.lastname: Mauroy
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. elevy@ulg.ac.be.
authors.forename: Etienne
authors.initials: E
authors.lastname: Lévy
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. dominique.cassart@ulg.ac.be.
authors.forename: Dominique
authors.initials: D
authors.lastname: Cassart
authors.affiliation: Department of Clinical Sciences, University of Liège, Liège, Belgium. dpeeters@ulg.ac.be.
authors.forename: Dominique
authors.initials: D
authors.lastname: Peeters
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis, Faculty of Medicine, Free University of Brussels, Brussels, Belgium. lcponce@ulb.ac.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Poncelet
authors.affiliation: Department of Morphology and Pathology, University of Liège, Liège, Belgium. daniel.desmecht@ulg.ac.be.
authors.forename: Daniel
authors.initials: D
authors.lastname: Desmecht
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D002415:Cats; D054022:Cerebrum / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis; D005254:Feline Panleukopenia / Q000821:virology*; D028301:Feline Panleukopenia Virus / Q000302:isolation & purification*; D005260:Female; D008297:Male; D009474:Neurons / Q000821:virology*
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral