A novel tetracycline-inducible viral replication switch.
With the cloning of DNA encoding the trans-dominant negative mutant form of the HSV-1 origin-binding protein UL9, UL9-C535C, under the control of the tet operator-bearing hCMV major immediate-early promoter (pcmvtetO), this article demonstrates that the tetR-mediated mammalian transcription repression switch (Yao et al., Hum. Gene Ther. 9:1939-1950, 1998) can be converted to a novel HSV-1-specific viral replication switch. Using this viral replication switch, the plaque-forming efficiency of infectious HSV-1 DNA can be reversibly regulated by tetR over 100-fold in transient viral infection assays. Moreover, while less than 0 PFU/ml of HSV-1 was detected from tetR-expressing cells transfected with infectious HSV-1 DNA and plasmid pcmvtetOUL9-C535C in the presence of tetracycline, close to 1000 PFU/ml of HSV-1 was produced when similar experiments were carried out in the absence of tetracycline. The tetracycline treatment led no reduction in HSV-1 synthesis in cells transfected with infectious HSV-1 DNA alone. Taken together, given that the UL9-C535C-associated antiviral activity can be silenced in the context of this HSV-1 replication switch, the establishment of this reversible switch would allow construction of a new generation of HSV-1 recombinants able to inhibit its own replication as well as replication of wild-type virus.
Brigham and Women's Hospital, and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA. FYao@RICS.BWH.Harvard.Edu
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D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D003587:Cytomegalovirus / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D015967:Gene Expression Regulation, Viral; D005809:Genes, Regulator; D005822:Genetic Vectors; D018259:Herpesvirus 1, Human / Q000235:genetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D012516:Osteosarcoma / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000494:pharmacology; D013752:Tetracycline / Q000378:metabolism* / Q000494:pharmacology; D014162:Transfection; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics*; D014765:Viral Vaccines; D014779:Virus Replication / Q000235:genetics*
D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D014764:Viral Proteins; D014765:Viral Vaccines; C034811:tetracycline resistance-encoding transposon repressor protein; C064565:UL9 protein, Human herpesvirus 1; D013752:Tetracycline