The antiviral and antiproliferative actions of interferons have been correlated with a number of enzyme activities (2-5A synthetase, endoribonuclease, protein kinase), which, when activiated, inhibit protein synthesis but the relevance of these enzymes to the inhibition of replication of RNA and DNA-containing viruses has not been elucidated. We have found in a vaccinia virus infected mouse L cell system that the interferon-mediated inhibition of viral protein synthesis in vivo correlates with activation of the 2-5A synthetase/endonuclease and degradation of viral RNAs. In contrast, in a number of mouse and human cells of different origins, vaccinia protein synthesis is not inhibited by interferon and a novel phenomenon has been discovered where vaccinia products block the 2-5A synthetase and protein kinase activities. In this proposal, experiments are described using vaccinia virus as a model system to elucidate: a) the in vivo role of the 2-5A synthetase/endonuclease system in the interferon-mediated inhibition of vaccinia virus protein synthesis; b) the mechanism by which a DNA virus such as vaccinia escapes blockade by the interferon system. To determine the in vivo role of the 2-5A synthetase/endonuclease on protein synthesis we will establish to what extent the integrity of viral and cellular RNAs is related to a block of translation, if specific degradation of certain RNAs occurs and if these events are the result of the formation of viral RNA during the course of infection. To define how vaccinia virus escapes inhibition by the interferon-mediated enzyme activities, we will characterize the nature and mode of action of vaccinia products with interfering properties present in cell-extracts and virions. To further define the vaccinia products with blocking effects on interferon action we will examine whether viral genes introduced into cells by DNA-mediated gene transfer can overcome specific interferon-mediated enzyme activities. By examining these cell-systems where the interferon response of the cells may be controlled by vaccinia gene(s) we may provide the means to define the mechanisms responsible for inhibition of replication of various viruses as well as the antiproliferative actions of interferons.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA044262-09
Application #
3186793
Study Section
Virology Study Section (VR)
Project Start
1983-09-30
Project End
1991-06-30
Budget Start
1988-07-01
Budget End
1989-06-30
Support Year
9
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Suny Downstate Medical Center
Department
Type
Schools of Medicine
DUNS #
068552207
City
Brooklyn
State
NY
Country
United States
Zip Code
11203
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Diaz-Guerra, M; Kahn, J S; Esteban, M (1993) A mutation of the nucleoside triphosphate phosphohydrolase I (NPH-I) gene confers sensitivity of vaccinia virus to interferon. Virology 197:485-91
Demkowicz, W E; Maa, J S; Esteban, M (1992) Identification and characterization of vaccinia virus genes encoding proteins that are highly antigenic in animals and are immunodominant in vaccinated humans. J Virol 66:386-98
Rodriguez, J R; Rodriguez, D; Esteban, M (1992) Insertional inactivation of the vaccinia virus 32-kilodalton gene is associated with attenuation in mice and reduction of viral gene expression in polarized epithelial cells. J Virol 66:183-9
Rodriguez, J R; Rodriguez, D; Esteban, M (1991) Interferon treatment inhibits early events in vaccinia virus gene expression in infected mice. Virology 185:929-33
Lai, C F; Gong, S C; Esteban, M (1991) The purified 14-kilodalton envelope protein of vaccinia virus produced in Escherichia coli induces virus immunity in animals. J Virol 65:5631-5
Lai, C F; Gong, S C; Esteban, M (1991) The 32-kilodalton envelope protein of vaccinia virus synthesized in Escherichia coli binds with specificity to cell surfaces. J Virol 65:499-504
Rodriguez, D; Rodriguez, J R; Ojakian, G K et al. (1991) Vaccinia virus preferentially enters polarized epithelial cells through the basolateral surface. J Virol 65:494-8
Maa, J S; Rodriguez, J F; Esteban, M (1990) Structural and functional characterization of a cell surface binding protein of vaccinia virus. J Biol Chem 265:1569-77
Rodriguez, D; Zhou, Y W; Rodriguez, J R et al. (1990) Regulated expression of nuclear genes by T3 RNA polymerase and lac repressor, using recombinant vaccinia virus vectors. J Virol 64:4851-7

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