title: Antiviral efficacy of nine nucleoside reverse transcriptase inhibitors against feline immunodeficiency virus in feline peripheral blood mononuclear cells.
abstract: OBJECTIVE
  To compare cytotoxic effects and antiviral efficacy of 9 nucleoside reverse transcriptase inhibitors (NRTIs) against FIV in feline peripheral blood mononuclear cells.
  
  
  METHODS
  Peripheral blood mononuclear cells obtained from 3 specific pathogen-free cats.
  
  
  METHODS
  3 of the 9 NRTIs had not been previously assessed in feline cell lines. Cytotoxic effects were determined by colorimetric quantification of a formazan product resulting from bioreduction of a tetrazolium reagent by viable peripheral blood mononuclear cells; uninfected cells from 1 cat were used in these assays. Cells from all 3 cats were infected with a pathogenic clone of FIV, and in vitro antiviral efficacy of each NRTI was assessed with an FIV p24 antigen capture ELISA.
  
  
  RESULTS
  Cytotoxic effects in feline peripheral blood mononuclear cells were observed only at concentrations > 10 μM for all 9 NRTIs. Comparison of the cytotoxic effect at the highest concentration investigated (500 μM) revealed that didanosine and amdoxovir were significantly less toxic than abacavir. All drugs induced a dose-dependent reduction of FIV replication. At the highest concentration investigated (10 μM), there was no significant difference in antiviral efficacy among the test compounds.
  
  
  CONCLUSIONS
  The evaluated NRTIs had low cytotoxicity against feline peripheral blood mononuclear cells and appeared to be safe options for further in vivo evaluation for the treatment of FIV-infected cats. There was no evidence suggesting that the newly evaluated compounds would be superior to the existing NRTIs for reducing FIV burden of infected cats.
authors.affiliation: Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.
authors.forename: Anita M
authors.initials: AM
authors.lastname: Schwartz
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: McCrackin
authors.forename: Raymond F
authors.initials: RF
authors.lastname: Schinazi
authors.forename: Peter B
authors.initials: PB
authors.lastname: Hill
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Vahlenkamp
authors.forename: Mary B
authors.initials: MB
authors.lastname: Tompkins
authors.forename: Katrin
authors.initials: K
authors.lastname: Hartmann
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002415:Cats; D002460:Cell Line; D016089:Immunodeficiency Virus, Feline / Q000187:drug effects*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000821:virology*; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D018894:Reverse Transcriptase Inhibitors