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DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation

The transcription factors IRF3 and NF-κB are crucial in innate immune signalling in response to many viral and bacterial pathogens. However, mechanisms leading to their activation remain incompletely understood. Viral RNA can be detected by RLR receptors, such as RIG-I and MDA5, and the dsRNA recept...

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Autores principales: Pallett, Mitchell A., Lu, Yongxu, Smith, Geoffrey L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8875258/
https://www.ncbi.nlm.nih.gov/pubmed/35215908
http://dx.doi.org/10.3390/v14020316
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author Pallett, Mitchell A.
Lu, Yongxu
Smith, Geoffrey L.
author_facet Pallett, Mitchell A.
Lu, Yongxu
Smith, Geoffrey L.
author_sort Pallett, Mitchell A.
collection PubMed
description The transcription factors IRF3 and NF-κB are crucial in innate immune signalling in response to many viral and bacterial pathogens. However, mechanisms leading to their activation remain incompletely understood. Viral RNA can be detected by RLR receptors, such as RIG-I and MDA5, and the dsRNA receptor TLR3. Alternatively, the DExD-Box RNA helicases DDX1-DDX21-DHX36 activate IRF3/NF-κB in a TRIF-dependent manner independent of RIG-I, MDA5, or TLR3. Here, we describe DDX50, which shares 55.6% amino acid identity with DDX21, as a non-redundant factor that promotes activation of the IRF3 signalling pathway following its stimulation with viral RNA or infection with RNA and DNA viruses. Deletion of DDX50 in mouse and human cells impaired IRF3 phosphorylation and IRF3-dependent endogenous gene expression and cytokine/chemokine production in response to cytoplasmic dsRNA (polyIC transfection), and infection by RNA and DNA viruses. Mechanistically, whilst DDX50 co-immunoprecipitated TRIF, it acted independently to the previously described TRIF-dependent RNA sensor DDX1. Indeed, shRNA-mediated depletion of DDX1 showed DDX1 was dispensable for signalling in response to RNA virus infection. Importantly, loss of DDX50 resulted in a significant increase in replication and dissemination of virus following infection with vaccinia virus, herpes simplex virus, or Zika virus, highlighting its important role as a broad-ranging viral restriction factor.
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spelling pubmed-88752582022-02-26 DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation Pallett, Mitchell A. Lu, Yongxu Smith, Geoffrey L. Viruses Article The transcription factors IRF3 and NF-κB are crucial in innate immune signalling in response to many viral and bacterial pathogens. However, mechanisms leading to their activation remain incompletely understood. Viral RNA can be detected by RLR receptors, such as RIG-I and MDA5, and the dsRNA receptor TLR3. Alternatively, the DExD-Box RNA helicases DDX1-DDX21-DHX36 activate IRF3/NF-κB in a TRIF-dependent manner independent of RIG-I, MDA5, or TLR3. Here, we describe DDX50, which shares 55.6% amino acid identity with DDX21, as a non-redundant factor that promotes activation of the IRF3 signalling pathway following its stimulation with viral RNA or infection with RNA and DNA viruses. Deletion of DDX50 in mouse and human cells impaired IRF3 phosphorylation and IRF3-dependent endogenous gene expression and cytokine/chemokine production in response to cytoplasmic dsRNA (polyIC transfection), and infection by RNA and DNA viruses. Mechanistically, whilst DDX50 co-immunoprecipitated TRIF, it acted independently to the previously described TRIF-dependent RNA sensor DDX1. Indeed, shRNA-mediated depletion of DDX1 showed DDX1 was dispensable for signalling in response to RNA virus infection. Importantly, loss of DDX50 resulted in a significant increase in replication and dissemination of virus following infection with vaccinia virus, herpes simplex virus, or Zika virus, highlighting its important role as a broad-ranging viral restriction factor. MDPI 2022-02-03 /pmc/articles/PMC8875258/ /pubmed/35215908 http://dx.doi.org/10.3390/v14020316 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Pallett, Mitchell A.
Lu, Yongxu
Smith, Geoffrey L.
DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation
title DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation
title_full DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation
title_fullStr DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation
title_full_unstemmed DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation
title_short DDX50 Is a Viral Restriction Factor That Enhances IRF3 Activation
title_sort ddx50 is a viral restriction factor that enhances irf3 activation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8875258/
https://www.ncbi.nlm.nih.gov/pubmed/35215908
http://dx.doi.org/10.3390/v14020316
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