Nitric oxide down-regulates Epstein-Barr virus reactivation in epithelial cell lines.
Nitric oxide (NO), a mediator of biological functions, has an antimicrobial activity against a variety of pathogens including viruses. In this study, we found that a constitutive, low level of inducible NO synthase (iNOS) mRNA was expressed in the EBV-infected gastric tissue-derived GT38 and GT39 cell lines, by analysis with the reverse transcription-polymerase chain reaction (RT-PCR) and Southern blotting. Treatment of these cells with a specific NOS inhibitor, NG-monomethyl-L-arginine (L-NMMA), induced the immediate-early, EBV transactivator gene BZLF1 protein ZEBRA, suggesting a significant increase in EBV reactivation by L-NMMA. Northern blotting demonstrated that BZLF1 and BRLF1 transcripts were also induced by 12-O-tetradecanoylphorbol-13 acetate (TPA). Meanwhile, constitutive expression of iNOS mRNA was inhibited by TPA. L-NMMA also enhanced TPA-induced expression of the BZLF1 gene. On the other hand, a NO donor, S-nitroso-N-acetylpenicillamine (SNAP), which releases NO in an aqueous solution, inhibited the TPA-induced BZLF1 gene expression in a dose-dependent manner at both mRNA and protein levels. These results demonstrated that NO is a regulatory factor in maintaining virus latency via inhibiting EBV reactivation in the infected epithelial cells.
Gao
X
X
School of Life Science, Faculty of Medicine, Tottori University, Nishimachi-86, Yonago, 683-8505, Japan.
Tajima
M
M
Sairenji
T
T
D000818:Animals; D002144:Callithrix; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000821:virology; D005786:Gene Expression Regulation / Q000187:drug effects; D004854:Herpesvirus 4, Human / Q000254:growth & development*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics; D008934:Mitogens / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015534:Trans-Activators / Q000235:genetics; D014764:Viral Proteins; D014775:Virus Activation; D019323:omega-N-Methylarginine / Q000494:pharmacology
C068382:BRLF1 protein, Human herpesvirus 4; C063676:BZLF1 protein, Herpesvirus 4, Human; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D017874:Immediate-Early Proteins; D008934:Mitogens; C110881:S-nitro-N-acetylpenicillamine; D015534:Trans-Activators; D014764:Viral Proteins; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D010396:Penicillamine; D013755:Tetradecanoylphorbol Acetate