ENGINEERING PROTEINS THAT SUBVERT VIRAL HOST EVASION MECHANISMS TO ELICIT PROTECTION AGAINST A BROAD RANGE OF VIRAL INFECTIONS
Document Type
Presentation
Start Date
22-10-2010 3:00 PM
End Date
22-10-2010 4:30 PM
Description
The Holy Grail for development of antiviral agents is to generate therapeutics that elicit protection against a multitude of viral pathogens. A host's control of viral infection is mediated through cellular sentinels that detect pathogen invasion and initiate both innate and adaptive responses. Key to these responses is the production of type-1 interferons (IFN). HSV-2 was found to completely abolish type-1 IFN antiviral responses by specifically targeting one component, STAT2, of the tripartite interferon signaling complex via multiple mechanisms: 1) HSV-2 specifically degraded STAT2 protein in a proteosome dependent manner. 2) HSV-2 prevented new STAT2 protein expression by degrading STAT2 mRNA. 3) HSV-2 inhibited activation of IFN signaling cascades by preventing phosphorylation of STAT2. 4) HSV-2 sequestered STAT2 within the cytoplasm of infected cells and prevented its translocation to the nucleus. Although these mechanisms for evasion of IFN responses are complex and redundant by other virus family standards, aspects of each are highly conserved among most viruses. Therefore, we developed chimeric cellular proteins capable of subverting virus-mediated evasion mechanisms by utilizing our understanding of how HSV-2 escapes IFN-associated suppression of viral replication. In order to circumvent destruction of STAT2, the amino terminus of STAT2 was excluded and the transactivation domain of STAT2 was fused to IRF9. Induced expression of the IRF9:STAT2 chimera potently induced the expression of IFN-associated antiviral genes and prevented efficient replication of HSV-2, as well as the RNA virus VSV. In conclusion, understanding the basic mechanisms viruses employ to evade host cell-intrinsic pathogen response pathways enables the engineered recapitulation of IFN-associated antiviral gene expression and elicits protection of host cells from viral infections.
Recommended Citation
Sanchez, Rebecca; Kadeppagari, R.; and Foster, T., "ENGINEERING PROTEINS THAT SUBVERT VIRAL HOST EVASION MECHANISMS TO ELICIT PROTECTION AGAINST A BROAD RANGE OF VIRAL INFECTIONS" (2010). Dr. Joseph M. Moerschbaecher, III Graduate Research Day. 20.
https://digitalscholar.lsuhsc.edu/grad_rs/2010/poster2/20
ENGINEERING PROTEINS THAT SUBVERT VIRAL HOST EVASION MECHANISMS TO ELICIT PROTECTION AGAINST A BROAD RANGE OF VIRAL INFECTIONS
The Holy Grail for development of antiviral agents is to generate therapeutics that elicit protection against a multitude of viral pathogens. A host's control of viral infection is mediated through cellular sentinels that detect pathogen invasion and initiate both innate and adaptive responses. Key to these responses is the production of type-1 interferons (IFN). HSV-2 was found to completely abolish type-1 IFN antiviral responses by specifically targeting one component, STAT2, of the tripartite interferon signaling complex via multiple mechanisms: 1) HSV-2 specifically degraded STAT2 protein in a proteosome dependent manner. 2) HSV-2 prevented new STAT2 protein expression by degrading STAT2 mRNA. 3) HSV-2 inhibited activation of IFN signaling cascades by preventing phosphorylation of STAT2. 4) HSV-2 sequestered STAT2 within the cytoplasm of infected cells and prevented its translocation to the nucleus. Although these mechanisms for evasion of IFN responses are complex and redundant by other virus family standards, aspects of each are highly conserved among most viruses. Therefore, we developed chimeric cellular proteins capable of subverting virus-mediated evasion mechanisms by utilizing our understanding of how HSV-2 escapes IFN-associated suppression of viral replication. In order to circumvent destruction of STAT2, the amino terminus of STAT2 was excluded and the transactivation domain of STAT2 was fused to IRF9. Induced expression of the IRF9:STAT2 chimera potently induced the expression of IFN-associated antiviral genes and prevented efficient replication of HSV-2, as well as the RNA virus VSV. In conclusion, understanding the basic mechanisms viruses employ to evade host cell-intrinsic pathogen response pathways enables the engineered recapitulation of IFN-associated antiviral gene expression and elicits protection of host cells from viral infections.
Comments
See abstract book page 64