HSV-1 infected cell proteins influence tetracycline-regulated transgene expression.
J Gene Med
; 2(5): 379-89, 2000.
Article
em En
| MEDLINE
| ID: mdl-11045432
ABSTRACT
BACKGROUND:
This study investigates elements of herpes simplex virus type 1 (HSV-1) which influence transgene expression in tetracycline-regulated expression systems.METHODS:
Different HSV-1 mutants were used to infect Vero cells that had been transfected with plasmids containing the luciferase gene under the control of tet-off or tet-on tetracycline-regulation systems.RESULTS:
The baseline level of luciferase expression was elevated after infection with HSV-1 mutants lacking one or more immediate early genes encoding transactivating factors ICP27, ICP4 and ICP0. With the tet-off system, not only was baseline expression elevated, but there was a complete loss of induction upon removal of tet when this regulatory system was brought into the cell by infection with helper virus-free amplicon vectors. Elevation of luciferase expression was also observed upon infection with the same HSV-1 mutants following transfection with a plasmid containing only a CMV minimal promoter driving luciferase (pUHC13-3). Only one HSV mutant (14Hdelta3), which bears a disruption in the transactivation domain of VP16 and is deleted for both ICP4 genes, did not increase baseline luciferase expression after transfection of pUHC13-3. The disregulating effects were dependent on virus dose and were not influenced by treatment with interferon (IFN)-alpha, which suppresses viral gene expression. Additional assays involving cotransfection of pUHC13-3 with a plasmid encoding of the HSV-1 transactivating factor ICP4 revealed that ICP4 was the most potent inducer of gene expression from the tetO/CMV minimal promoter.CONCLUSION:
These results indicate that proteins encoded in the HSV-1 genome, especially the transactivating immediate early gene products (ICP4, ICP27 and ICP0) and the VP16 tegument protein can activate the tetO/ minimal CMV promoter and thereby interfere with the integrity of tetracycline-regulated transgene expression.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tetraciclina
/
Expressão Gênica
/
Herpesvirus Humano 1
/
Técnicas de Transferência de Genes
Limite:
Animals
Idioma:
En
Revista:
J Gene Med
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA MEDICA
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos