title: Inhibition of visna virus replication by 2',3'-dideoxynucleosides and acyclic nucleoside phosphonate analogs.
abstract: A series of acyclic nucleoside phosphonate (ANP) and 2',3'-dideoxynucleoside (ddN) derivatives were evaluated for their inhibitory effects on visna virus replication and maedi/visna virus-induced syncytium formation in sheep choroid plexus cells. Most ANP derivatives inhibited virus replication and syncytium formation within a concentration range of 0.2 to 1.8 microM. Among the most active ANP derivatives ranked (R)-9-(2-phosphonomethoxypropyl)adenine, (R)-9-(2-phosphonomethoxypropyl)-2,6-diaminopurine, and (S)-9-(3-fluoro-2-phosphonomethoxypropyl)adenine. Of the ddN derivatives, 2',3'-dideoxycytidine (ddCyd) proved to be the most inhibitory to visna virus-induced syncytium formation (50% effective concentration, 0.02 microM). The purine ddN analogs (i.e., 2',3'-dideoxyinosine, 2',3'-dideoxyadenosine, 2',3'-dideoxyguanosine, and 2,6-diaminopurine-2',3'-dideoxyribosine) were 10- to 30-fold less effective, and the thymidine derivatives 2',3'-didehydro-2',3'-dideoxythymidine (D4T) and 3'-azido-2',3'-dideoxythymidine (AZT) were more than 500-fold less inhibitory to visna virus than ddCyd. The 5'-triphosphate forms of AZT and D4T were 100- to 600-fold more inhibitory to visna virus particle-derived reverse transcriptase than was the 5'-triphosphate of ddCyd. The apparent discrepancy between the inhibitory effects of these ddN derivatives on virus replication and viral reverse transcriptase activity most likely reflects differences in the metabolic conversion of ddCyd versus D4T and AZT in sheep choroid plexus cells.
authors.affiliation: Institute of Biology, University of Iceland, Reykjavik.
authors.forename: H
authors.initials: H
authors.lastname: Thormar
authors.forename: J
authors.initials: J
authors.lastname: Balzarini
authors.forename: A
authors.initials: A
authors.lastname: Holy
authors.forename: J
authors.initials: J
authors.lastname: Jindrich
authors.forename: I
authors.initials: I
authors.lastname: Rosenberg
authors.forename: Z
authors.initials: Z
authors.lastname: Debyser
authors.forename: J
authors.initials: J
authors.lastname: Desmyter
authors.forename: E
authors.initials: E
authors.lastname: De Clercq
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002831:Choroid Plexus / Q000166:cytology / Q000382:microbiology; D015224:Dideoxynucleosides / Q000494:pharmacology*; D006678:HIV / Q000187:drug effects / Q000201:enzymology; D008826:Microbial Sensitivity Tests; D009705:Nucleosides / Q000494:pharmacology*; D063065:Organophosphonates / Q000494:pharmacology*; D018894:Reverse Transcriptase Inhibitors; D012756:Sheep; D014779:Virus Replication / Q000187:drug effects*; D014790:Visna-maedi virus / Q000187:drug effects* / Q000472:pathogenicity / Q000502:physiology*
chemical_list: D000998:Antiviral Agents; D015224:Dideoxynucleosides; D009705:Nucleosides; D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors