Resistance of Herpes Simplex Virus to Adenine Arabinoside and E-5-(2-Bromovinyl)-2′-Deoxyuridine: A Physical Analysis

Herpes simplex virus mutants PAAr5, AraAr6, AraAr7, AraAr9, and AraArl3, which previously had been shown to be resistant to arabinosyladenine (araA) alone, were found to be resistant to araA in the presence of high concentrations of the adenosine deaminase inhibitor, deoxycoformycin. The marker conferring resistance to araA and deoxycoformycin in mutant PAAr5 was mapped finely to an 0.8-kilobase-pair region in the herpes simplex virus DNA polymerase locus. These results indicate that the mutants are resistant to araA itself rather than to its deamination product and confirm the importance of the viral polymerase in the antiviral action of araA.Arabinosyladenine (9-p-D-arabinofuranosyladenine, vi- (4-6, 12, 16, 20, 23, 24, 29). Additionally, a mutant previously isolated for PAA resistance, PAAr5 (24), was found to be resistant to araA. The araA resistance and PAA resistance markers of this mutant were shown to be closely linked; moreover, the mutant specified HSV DNA polymerase activity which exhibited a higher Ki for araATP (8). These findings have been extended in a study mapping the araA and PAA resistance markers of PAAr5 to a 1.1-kilobase-pair (kbp) fragment in the pol locus (6) and in a report mapping an araA resistance marker from another mutant to a 2.6-kbp fragment in the pol locus (11). These studies led to the conclusions that araA acts selectively on HSV and that the DNA polymerase is a target of araA action (8).Recently, several mutants isolated for resistance to phosphonoformic acid (PFA) (12), a congener of PAA, were found to be resistant to araA (2). However, when an inhibitor of adenosine deaminase, deoxycoformycin (pentostatin, covidarabine [DCF]) (40), was included with the araA, it was reported that resistance was abolished (2). These findings, along with kinetic analyses of the mutant polymerases, were used both to support the conclusion that the araA resistance observed for previously described mutants (8, 31) was probably due to the omission of an adenosine deaminase inhibitor and to suggest that what had been observed was not resistance to araA but resistance to the deamination product of araA, arabinosylhypoxanthine (araHx). On this basis, it was suggested that determinants * Corresponding author.other than the HSV DNA polymerase are probably important for the antiviral action of araA (2).To address these questions, we have reexamined the araA-resistant mutants upon which previous conclusions implicating the HSV DNA polymerase as a target for this drug were based (6,8). We find that these mutants retain their resistance to araA in the presence of DCF. Moreover, this resistance can be mapped finely to an 0.8-kbp region in the HSV DNA polymerase locus, confirming that the HSV DNA polymerase is important for the antiviral action of araA.MATERIALS AND METHODS Cells and viruses. African green monkey kidney cells (Vero cells) were propagated and maintained as described previously (38). Viruses used included HSV type 1 wild-type strain KOS, mutants 19,24), AraAr6, AraAr7, AraAr9, and AraArl3 (...

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confidence: 77%

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See 1 more Smart Citation

Herpes simplex virus mutants resistant to arabinosyladenine in the presence of deoxycoformycin

Fleming¹,

Coen²

1984

“…Since their antiviral activity depends on the presence of specific viral enzymes, they cannot be broad-spectrum antiviral agents and act on viruses that belong to families phylogenetically distant. Viral mutants readily arise upon treatment with a given nucleoside analog (4). Therefore, more-selective inhibitors that block different steps of viral replication are needed (7).…”

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confidence: 99%

Mode of action of a new type of UDP-glucose analog against herpesvirus replication

Alarcón

González

Carrasco

et al. 1988

The mode of action of a new type of UDP-glucose analog against herpes simplex virus type 1 (HSV-1) replication was examined. The analog showed good selectivity and potent activity. At 10 ,ug/ml, P-536 inhibited the formation of infectious HSV-1 by more than 90%, whereas at 100 ,ug/ml it had no cytotoxic effects, as evidenced by phase-contrast microscopy. P-536 showed a wide spectrum of action and was active against HSV-1, adenovirus type 5, vaccinia virus, poliovirus type 1, encephalomyocarditis virus, vesicular stomatitis virus, influenza virus, and measles virus, irrespective of whether these viruses have lipidic envelopes or not. P-536 clearly inhibited protein glycosylation if added at the time when late viral proteins were being synthesized. Moreover, it also interfered with the synthesis of nucleic acids and the phosphorylation of nucleosides. If P-536 was present from the beginning of infection, HSV-1 replication was blocked at an early step and the infected cells continued to synthesize cellular proteins for long periods.

“…For example, the isolation of mutants resistant to arabinosyladenine (vidarabine [araA]) (6,9) demonstrated that, despite its cytotoxicity, araA is selective against HSV. Thus far, all araA resistance mutations have been mapped to the HSV DNA polymerase (pol) gene (2, 6,7,9), demonstrating that the polymerase is a target of araA and contributes to its selectivity.…”

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confidence: 99%

Mutation within the herpes simplex virus DNA polymerase gene conferring resistance to (R)-9-(3,4-dihydroxybutyl)guanine

Chiou¹,

Kerns²,

Coen³

1986

Five herpes simplex virus mutants known or presumed to contain mutations in their DNA polymerase genes conferring resistance to acyclovir and arabinosyladenine also proved to exhibit some degree of resistance to (R)-9-(3,4-dihydroxybutyl)guanine (buciclovir). For one mutant, a buciclovir resistance mutation was mapped to a region of the viral DNA polymerase gene proposed to encode the deoxynucleoside 5'-triphosphate binding domain. These data implicate the viral polymerase as a target of buciclovir action that contributes to its antiviral selectivity.