1. Pentostatin antagonizes the antiviral activity of MBX-2168 by inhibiting the biosynthesis of the active compound.
- Author
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Hagen NR, Nguyen ML, Williams JD, Bowlin TL, and Gentry BG
- Subjects
- Acyclovir pharmacology, Animals, Cell Line, Chlorocebus aethiops, Cyclopropanes pharmacology, Cytomegalovirus Infections drug therapy, Cytomegalovirus Infections virology, Fibroblasts virology, Foreskin cytology, Ganciclovir pharmacology, Guanine antagonists & inhibitors, Guanine pharmacology, Herpes Simplex drug therapy, Herpes Simplex virology, Host Microbial Interactions, Humans, Loss of Function Mutation, Male, Phosphorylation, Vero Cells, Virus Replication drug effects, Antiviral Agents antagonists & inhibitors, Antiviral Agents pharmacology, Cyclopropanes antagonists & inhibitors, Cytomegalovirus drug effects, Guanine analogs & derivatives, Herpesvirus 1, Human drug effects, Pentostatin pharmacology, Polyphosphates metabolism
- Abstract
MBX-2168 has a mechanism of action similar to that of acyclovir (ACV) and ganciclovir (GCV), but two unique steps differentiate this drug from ACV/GCV. First, MBX-2168 is, at least partially, phosphorylated by the endogenous cellular kinase TAOK3 to a monophosphate. The second involves the removal of a moiety at the 6-position of MBX-2168-MP by adenosine deaminase like protein-1 (ADAL-1). It has been previously demonstrated that co-incubation with pentostatin (dCF), an ADAL-1 inhibitor, antagonizes the anti-viral activity of MBX-2168. We therefore hypothesize that inhibiting ADAL-1 results in a reduction of active compound produced in virus-infected cells. To test this, we examined the effect dCF has on the conversion of MBX-2168 to a triphosphate in HSV-1 and HCMV-infected cells. Our results demonstrate incubation of MBX-2168 alone or with dCF in HCMV-infected cells resulted in 53.1 ± 0.7 and 39.4 ± 1.5 pmol triphosphate/10
6 cells at 120 h, respectively. Incubation of MBX-2168 alone or with dCF in Vero cells resulted in 12.8 ± 0.1 and 6.7 ± 0.7 pmol triphosphate/106 cells at 24 h, respectively. HSV-1-infected Vero cells demonstrated no statistical difference in triphosphate accumulation at 24 h (13.1 ± 0.3 pmol triphosphate/106 cells). As expected, incubation with dCF resulted in the accumulation of MBX-2168-MP in both HFF (9.8 ± 0.9 pmol MBX-2168-MP/106 cells at 120 h) and Vero cells (4.7 ± 0.3 pmol MBX-2168-MP/106 cells at 24 h) while no detectable levels of monophosphate were observed in cultures not incubated with dCF. We conclude that dCF antagonizes the anti-viral effect of MBX-2168 by inhibiting the production of triphosphate, the active compound., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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