title: Acyclovir diphosphate dimyristoylglycerol: a phospholipid prodrug with activity against acyclovir-resistant herpes simplex virus.
abstract: Infection with herpes simplex viruses (HSVs) resistant to treatment with acyclovir (9-[(2-hydroxyethoxy)-methyl]guanine, Zovirax) is a growing clinical problem in patients with AIDS and other immunosuppressed states. Most virus isolates resistant to acyclovir are deficient or defective in virally coded thymidine kinase (TK), which converts acyclovir to acyclovir monophosphate in virus-infected cells. To restore acyclovir efficacy, we synthesized acyclovir diphosphate dimyristoylglycerol, an analog of a naturally occurring phospholipid, CDP-diacylglycerol. Its biological activity was tested in WI38 human lung fibroblasts infected with the acyclovir-resistant DM21 strain of HSV, which is TK negative due to an 816-base-pair deletion in the TK coding region. Acyclovir diphosphate dimyristoylglycerol has substantial activity in DM21-infected cells (IC50 = 0.25 microM), whereas acyclovir and acyclovir monophosphate were ineffective (IC50 > 100 microM). Similar results were obtained in TK-altered and TK-deficient strains of HSV-1 and in acyclovir-resistant isolates of HSV-2 obtained from two AIDS patients. The phospholipid prodrug is active by means of TK-independent metabolic pathways that liberate acyclovir monophosphate inside the host cell. Acyclovir phosphates were 56 times greater in WI38 human lung fibroblasts incubated for 24 hr with [8-3H]acyclovir diphosphate dimyristoylglycerol relative to acyclovir. Acyclovir monophosphate added to the culture medium (outside the cell) did not circumvent the acyclovir resistance of the TK-negative DM21 mutant, presumably due to its conversion to acyclovir by phosphatases. Acyclovir diphosphate diacylglycerol prodrugs may be useful in treating TK-deficient mutant and wild-type strains of HSV.
authors.affiliation: Department of Medicine, University of California, San Diego.
authors.forename: K Y
authors.initials: KY
authors.lastname: Hostetler
authors.forename: S
authors.initials: S
authors.lastname: Parker
authors.forename: C N
authors.initials: CN
authors.lastname: Sridhar
authors.forename: M J
authors.initials: MJ
authors.lastname: Martin
authors.forename: J L
authors.initials: JL
authors.lastname: Li
authors.forename: L M
authors.initials: LM
authors.lastname: Stuhmiller
authors.forename: G M
authors.initials: GM
authors.lastname: van Wijk
authors.forename: H
authors.initials: H
authors.lastname: van den Bosch
authors.forename: M F
authors.initials: MF
authors.lastname: Gardner
authors.forename: K A
authors.initials: KA
authors.lastname: Aldern
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000382:microbiology; D000212:Acyclovir / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D000328:Adult; D000998:Antiviral Agents / Q000138:chemical synthesis / Q000633:toxicity*; D002460:Cell Line; D003673:Defective Viruses / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology; D004352:Drug Resistance, Microbial; D018259:Herpesvirus 1, Human / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology; D018258:Herpesvirus 2, Human / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D008168:Lung; D008297:Male; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010715:Phosphatidylglycerols / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D011355:Prodrugs / Q000633:toxicity*; D013937:Thymidine Kinase / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D010715:Phosphatidylglycerols; D011355:Prodrugs; C084886:acyclovir diphosphate dimyristoylglycerol; D013937:Thymidine Kinase; D000212:Acyclovir