The Murine Double-Stranded RNA-Dependent Protein Kinase PKR Is Required for Resistance to Vesicular Stomatitis Virus

ABSTRACT Interferon (IFN)-induced antiviral responses are mediated through a variety of proteins, including the double-stranded RNA-dependent protein kinase PKR. Here we show that fibroblasts derived from PKR−/− mice are more permissive for vesicular stomatitis virus (VSV) infection than are wild-type fibroblasts and demonstrate a deficiency in alpha/beta-IFN-mediated protection. We further show that mice lacking PKR are extremely susceptible to intranasal VSV infection, succumbing within days after instillation with as few as 50 infectious viral particles. Again, alpha/beta-IFN was unable to rescue PKR−/− mice from VSV infection. Surprisingly, intranasally infected PKR−/− mice died not from pathology of the central nervous system but rather from acute infection of the respiratory tract, demonstrating high virus titers in the lungs compared to similarly infected wild-type animals. These results confirm the role of PKR as the major component of IFN-mediated resistance to VSV infection. Since previous reports have shown PKR to be nonessential for survival in animals challenged with encephalomyocarditis virus, influenza virus, and vaccinia virus (N. Abraham et al., J. Biol. Chem. 274:5953–5962, 1999; Y. Yang et al., EMBO J. 14:6095–6106, 1995), our findings serve to highlight the premise that host dependence on the various mediators of IFN-induced antiviral defenses is pathogen specific.

Download Full-text

Inhibition of L-Deleted Foot-and-Mouth Disease Virus Replication by Alpha/Beta Interferon Involves Double-Stranded RNA-Dependent Protein Kinase

Journal of Virology ◽

10.1128/jvi.75.12.5498-5503.2001 ◽

2001 ◽

Vol 75 (12) ◽

pp. 5498-5503 ◽

Cited By ~ 105

Author(s):

Jarasvech Chinsangaram ◽

Marla Koster ◽

Marvin J. Grubman

Keyword(s):

Protein Kinase ◽

Disease Virus ◽

Foot And Mouth Disease ◽

Dependent Protein Kinase ◽

Double Stranded Rna ◽

Beta Interferon ◽

Mouth Disease Virus ◽

Dependent Protein ◽

Alpha Beta ◽

Fmdv Replication

ABSTRACT We previously demonstrated that the ability of foot-and-mouth disease virus (FMDV) to form plaques in cell culture is associated with the suppression of alpha/beta interferon (IFN-α/β). In the present study, we used Escherichia coli-expressed porcine and bovine IFN-α or -β individually to demonstrate that each was equally effective in inhibiting FMDV replication. The block in FMDV replication appeared to be at the level of protein translation, suggesting a role for double-stranded RNA-dependent protein kinase (PKR). In support of these findings, treatment of porcine and bovine cells with 2-aminopurine, an inhibitor of PKR, increased the yield of virus 8.8- and 11.2-fold, respectively, compared to that in untreated infected cells. In addition, results of FMDV infection in mouse embryonic fibroblast cells derived from gene knockout mice lacking the gene for RNase L−/− or PKR−/− or both indicated an important role for PKR in the inhibition of FMDV replication.

Download Full-text

NSs Protein of Rift Valley Fever Virus Induces the Specific Degradation of the Double-Stranded RNA-Dependent Protein Kinase

Journal of Virology ◽

10.1128/jvi.02148-08 ◽

2009 ◽

Vol 83 (9) ◽

pp. 4365-4375 ◽

Cited By ~ 166

Author(s):

Matthias Habjan ◽

Andreas Pichlmair ◽

Richard M. Elliott ◽

Anna K. Överby ◽

Timo Glatter ◽

...

Keyword(s):

Protein Kinase ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Wild Type ◽

Dependent Protein Kinase ◽

Valley Fever ◽

Double Stranded Rna ◽

Dependent Protein ◽

Specific Degradation

ABSTRACT Rift Valley fever virus (RVFV) continues to cause large outbreaks of acute febrile and often fatal illness among humans and domesticated animals in Africa, Saudi Arabia, and Yemen. The high pathogenicity of this bunyavirus is mainly due to the viral protein NSs, which was shown to prevent transcriptional induction of the antivirally active type I interferons (alpha/beta interferon [IFN-α/β]). Viruses lacking the NSs gene induce synthesis of IFNs and are therefore attenuated, whereas the noninducing wild-type RVFV strains can only be inhibited by pretreatment with IFN. We demonstrate here in vitro and in vivo that a substantial part of the antiviral activity of IFN against RVFV is due to a double-stranded RNA-dependent protein kinase (PKR). PKR-mediated virus inhibition, however, was much more pronounced for the strain Clone 13 with NSs deleted than for the NSs-expressing strain ZH548. In vivo, Clone 13 was nonpathogenic for wild-type (wt) mice but could regain pathogenicity if mice lacked the PKR gene. ZH548, in contrast, killed both wt and PKR knockout mice indiscriminately. ZH548 was largely resistant to the antiviral properties of PKR because RVFV NSs triggered the specific degradation of PKR via the proteasome. The NSs proteins of the related but less virulent sandfly fever Sicilian virus and La Crosse virus, in contrast, had no such anti-PKR activity despite being efficient suppressors of IFN induction. Our data suggest that RVFV NSs has gained an additional anti-IFN function that may explain the extraordinary pathogenicity of this virus.

Download Full-text