Mechanisms of inhibition of herpes simplex virus type 2 growth by 28-mer phosphorothioate oligodeoxycytidine.
The 28-mer phosphorothioate oligodeoxycytidine (S-(dC)28) has been reported previously to be a strong inhibitor of herpes simplex virus type 2 (HSV-2) DNA polymerase and HSV-2 growth in cell culture. In this study, the mechanism of action of S-(dC)28 was studied. S-(dC)28 was found to interfere with the adsorption of HSV-1 and HSV-2 to HeLa cells. HSV-2 infection, but not HSV-1, was found to potentiate the uptake of S-(dC)28 into HeLa cells. The enhanced uptake reached a plateau at 6-9 h postinfection and appeared to be dose-dependent and saturable at concentrations higher than 1 microM. The amount of S-(dC)28 accumulated in HSV-2 infected cells was found to be 50 pmol/10(6) cells at 6 h postinfection, whereas no significant drug accumulation was found in uninfected cells. S-(dC)28 binding studies suggested that there are several types of tight binding sites associated with HSV-2 virions, which could play a role in the enhancement of S-(dC)28 uptake. Subcellular distribution studies showed that intracellular S-(dC)28 was associated with both nuclei and cytoplasm and remained intact. Mechanism studies suggested three different mechanisms which could be responsible for the anti-HSV-2 action of S-(dC)28; (i) S-(dC)28 could interfere with the uptake of HSV. (ii) HSV-2 infection enhances the uptake of S-(dC)28 into cells. (iii) S-(dC)28 inhibits HSV-2 DNA synthesis, possibly, by inhibiting the viral DNA polymerase. The unique mechanisms of anti-HSV action of S-(dC)28 suggest it could be a potential new agent in anti-HSV-2 chemotherapy.
Gao
W Y
WY
Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06510.
Jaroszewski
J W
JW
Cohen
J S
JS
Cheng
Y C
YC
D000998:Antiviral Agents / Q000494:pharmacology*; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004261:DNA Replication / Q000187:drug effects; D004259:DNA-Directed DNA Polymerase / Q000096:biosynthesis / Q000378:metabolism; D003851:Deoxyribonucleases / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009838:Oligodeoxyribonucleotides / Q000378:metabolism / Q000494:pharmacology*; D018139:Simplexvirus / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D013873:Thionucleotides / Q000378:metabolism / Q000494:pharmacology*; D014771:Virion / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
D000998:Antiviral Agents; D009838:Oligodeoxyribonucleotides; D013873:Thionucleotides; C059536:Sd(C)28; D004259:DNA-Directed DNA Polymerase; D003851:Deoxyribonucleases