scholarly journals The Roles of Two IκB Kinase-related Kinases in Lipopolysaccharide and Double Stranded RNA Signaling and Viral Infection

2004 ◽  
Vol 199 (12) ◽  
pp. 1641-1650 ◽  
Author(s):  
Hiroaki Hemmi ◽  
Osamu Takeuchi ◽  
Shintaro Sato ◽  
Masahiro Yamamoto ◽  
Tsuneyasu Kaisho ◽  
...  
Keyword(s):  
Viral Infection ◽  
Toll Like Receptor ◽  
Regulatory Factor ◽  
Tlr Signaling ◽  
Dramatic Decrease ◽  
Embryonic Fibroblasts ◽  
Double Stranded Rna ◽  
Iκb Kinase ◽  
Inducible Genes ◽  
Rna Signaling

Viral infection and stimulation with lipopolysaccharide (LPS) or double stranded RNA (dsRNA) induce phosphorylation of interferon (IFN) regulatory factor (IRF)-3 and its translocation to the nucleus, thereby leading to the IFN-β gene induction. Recently, two IκB kinase (IKK)–related kinases, inducible IκB kinase (IKK-i) and TANK-binding kinase 1 (TBK1), were suggested to act as IRF-3 kinases and be involved in IFN-β production in Toll-like receptor (TLR) signaling and viral infection. In this work, we investigated the physiological roles of these kinases by gene targeting. TBK1-deficient embryonic fibroblasts (EFs) showed dramatic decrease in induction of IFN-β and IFN-inducible genes in response to LPS or dsRNA as well as after viral infection. However, dsRNA-induced expression of these genes was residually detected in TBK1-deficient cells and intact in IKK-i–deficient cells, but completely abolished in IKK-i/TBK1 doubly deficient cells. IRF-3 activation, in response not only to dsRNA but also to viral infection, was impaired in TBK1-deficient cells. Together, these results demonstrate that TBK1 as well as, albeit to a lesser extent, IKK-i play a crucial role in the induction of IFN-β and IFN-inducible genes in both TLR-stimulated and virus-infected EFs.

scholarly journals Differential Requirement for TANK-binding Kinase-1 in Type I Interferon Responses to Toll-like Receptor Activation and Viral Infection

2004 ◽  
Vol 199 (12) ◽  
pp. 1651-1658 ◽  
Author(s):  
Andrea K. Perry ◽  
Edward K. Chow ◽  
Julia B. Goodnough ◽  
Wen-Chen Yeh ◽  
Genhong Cheng
Keyword(s):  
Viral Infection ◽  
Nuclear Translocation ◽  
Sendai Virus ◽  
Cell Types ◽  
Receptor Activation ◽  
Northern Blotting ◽  
Type I ◽  
Toll Like Receptor ◽  
Embryonic Fibroblasts ◽  
Iκb Kinase

TANK-binding kinase-1 (TBK1) and the inducible IκB kinase (IKK-i) have been shown recently to activate interferon (IFN) regulatory factor-3 (IRF3), the primary transcription factor regulating induction of type I IFNs. Here, we have compared the role and specificity of TBK1 in the type I IFN response to lipopolysaccharide (LPS), polyI:C, and viral challenge by examining IRF3 nuclear translocation, signal transducer and activator of transcription 1 phosphorylation, and induction of IFN-regulated genes. The LPS and polyI:C-induced IFN responses were abolished and delayed, respectively, in macrophages from mice with a targeted disruption of the TBK1 gene. When challenged with Sendai virus, the IFN response was normal in TBK1−/− macrophages, but defective in TBK1−/− embryonic fibroblasts. Although both TBK1 and IKK-i are expressed in macrophages, only TBK1 but not IKK-i was detected in embryonic fibroblasts by Northern blotting analysis. Furthermore, the IFN response in TBK1−/− embryonic fibroblasts can be restored by reconstitution with wild-type IKK-i but not a mutant IKK-i lacking kinase activity. Thus, our studies suggest that TBK1 plays an important role in the Toll-like receptor–mediated IFN response and is redundant with IKK-i in the response of certain cell types to viral infection.

scholarly journals Priming Phosphorylation of TANK-Binding Kinase 1 by IκB Kinase β Is Essential in Toll-Like Receptor 3/4 Signaling

2019 ◽  
Vol 40 (5) ◽  
Author(s):  
Hiroto Abe ◽  
Junko Satoh ◽  
Yutaro Shirasaka ◽  
Amane Kogure ◽  
Hiroki Kato ◽  
...  
Keyword(s):  
Gene Deletion ◽  
Interferon Regulatory Factor ◽  
Toll Like Receptor ◽  
Regulatory Factor ◽  
Double Stranded Rna ◽  
Activate Transcription Factor ◽  
Iκb Kinase ◽  
Phosphorylation Cascade ◽  
Tlr3 Signaling ◽  
Inducible Gene

ABSTRACT TRIF is an essential adaptor for Toll-like receptor 3/4 (TLR3/4) signaling to activate transcription factor interferon regulatory factor 3 (IRF-3). We examined the molecular mechanism of TLR3 signaling and found that TLR3 stimulation by double-stranded RNA (dsRNA) induces phosphorylation of TRIF at Ser210 and is required for IRF-3 recruitment. TANK-binding kinase 1 (TBK1) is known to be responsible for IRF-3 phosphorylation and activation. We found that TBK1 is also responsible for phosphorylation of Ser210 in TRIF. Unexpectedly, we discovered that IκB kinase β (IKKβ) plays an essential role in TLR3/4 signaling using a pharmacological inhibitor and gene deletion. Of note, IKKβ is essential in TLR3/4 but not in retinoic acid-inducible gene I (RIG-I) signaling. Mechanistically, IKKβ transiently associates with and induces the phosphorylation of TBK1 upon TLR3 stimulation. These results suggest a phosphorylation cascade of IKKβ and TBK1, where priming phosphorylation of TBK1 by IKKβ is required to surpass the threshold to induce signaling, thereby activating IRF-3.

scholarly journals The microbiota protects from viral-induced neurologic damage through microglia-intrinsic TLR signaling

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
D Garrett Brown ◽  
Raymond Soto ◽  
Soumya Yandamuri ◽  
Colleen Stone ◽  
Laura Dickey ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Oral Administration ◽  
Viral Replication ◽  
Viral Infection ◽  
Host Defense ◽  
Toll Like Receptor ◽  
Tlr Signaling ◽  
The Central Nervous System ◽  
The Brain

Symbiotic microbes impact the function and development of the central nervous system (CNS); however, little is known about the contribution of the microbiota during viral-induced neurologic damage. We identify that commensals aid in host defense following infection with a neurotropic virus through enhancing microglia function. Germfree mice or animals that receive antibiotics are unable to control viral replication within the brain leading to increased paralysis. Microglia derived from germfree or antibiotic-treated animals cannot stimulate viral-specific immunity and microglia depletion leads to worsened demyelination. Oral administration of toll-like receptor (TLR) ligands to virally infected germfree mice limits neurologic damage. Homeostatic activation of microglia is dependent on intrinsic signaling through TLR4, as disruption of TLR4 within microglia, but not the entire CNS (excluding microglia), leads to increased viral-induced clinical disease. This work demonstrates that gut immune-stimulatory products can influence microglia function to prevent CNS damage following viral infection.

scholarly journals Double-stranded RNA Signaling by Toll-like Receptor 3 Requires Specific Tyrosine Residues in Its Cytoplasmic Domain

2002 ◽  
Vol 278 (7) ◽  
pp. 4393-4396 ◽  
Author(s):  
Saumendra N. Sarkar ◽  
Heather L. Smith ◽  
Theresa M. Rowe ◽  
Ganes C. Sen
Keyword(s):  
Cytoplasmic Domain ◽  
Toll Like Receptor ◽  
Double Stranded Rna ◽  
Tyrosine Residues ◽  
Rna Signaling

scholarly journals Interferon Regulatory Factor 3 and CREB-Binding Protein/p300 Are Subunits of Double-Stranded RNA-Activated Transcription Factor DRAF1

1998 ◽  
Vol 18 (3) ◽  
pp. 1359-1368 ◽  
Author(s):  
Brian K. Weaver ◽  
K. Prasanna Kumar ◽  
Nancy C. Reich
Keyword(s):  
Transcription Factor ◽  
Viral Infection ◽  
Interferon Regulatory Factor ◽  
Creb Binding Protein ◽  
Regulatory Factor ◽  
Double Stranded Rna ◽  
Interferon Stimulated Genes ◽  
Beta Interferon ◽  
Alpha Beta ◽  
Transcriptional Induction

ABSTRACT Cells respond to viral infection or double-stranded RNA with the transcriptional induction of a subset of alpha/beta interferon-stimulated genes by a pathway distinct from the interferon signal pathway. The transcriptional induction is mediated through a DNA sequence containing the alpha/beta interferon-stimulated response element (ISRE). We previously identified a novel transcription factor, designated double-stranded RNA-activated factor 1 (DRAF1), that recognizes this response element. The DNA-binding specificity of DRAF1 correlates with transcriptional induction, thereby distinguishing it as a positive regulator of alpha/beta interferon-stimulated genes. Two of the components of DRAF1 have now been identified as interferon regulatory factor 3 (IRF-3) and the transcriptional coactivator CREB-binding protein (CBP)/p300. We demonstrate that IRF-3 preexists in the cytoplasm of uninfected cells and translocates to the nucleus following viral infection. Translocation of IRF-3 is accompanied by an increase in serine and threonine phosphorylation. Coimmunoprecipitation analyses of endogenous proteins demonstrate an association of IRF-3 with the transcriptional coactivators CBP and p300 only subsequent to infection. In addition, antibodies to the IRF-3, CBP, and p300 molecules react with DRAF1 bound to the ISRE target site of induced genes. The cellular response that leads to DRAF1 activation and specific gene expression may serve to increase host survival during viral infection.

scholarly journals Identification of TBK1 complexes required for the phosphorylation of IRF3 and the production of interferon β

2017 ◽  
Vol 474 (7) ◽  
pp. 1163-1174 ◽  
Author(s):  
Siddharth Bakshi ◽  
Jordan Taylor ◽  
Sam Strickson ◽  
Thomas McCartney ◽  
Philip Cohen
Keyword(s):  
Sendai Virus ◽  
Interferon Regulatory Factor ◽  
Poly I:C ◽  
Hacat Cells ◽  
Regulatory Factor ◽  
Interferon Β ◽  
Present Evidence ◽  
Double Stranded Rna ◽  
Iκb Kinase ◽  
Ubiquitin Binding

The double-stranded RNA mimetic poly(I:C) and lipopolysaccharide (LPS) activate Toll-like receptors 3 (TLR3) and TLR4, respectively, triggering the activation of TANK (TRAF family member-associated NF-κB activator)-binding kinase 1 (TBK1) complexes, the phosphorylation of interferon regulatory factor 3 (IRF3) and transcription of the interferon β (IFNβ) gene. Here, we demonstrate that the TANK–TBK1 and optineurin (OPTN)–TBK1 complexes control this pathway. The poly(I:C)- or LPS-stimulated phosphorylation of IRF3 at Ser396 and production of IFNβ were greatly reduced in bone marrow-derived macrophages (BMDMs) from TANK knockout (KO) mice crossed to knockin mice expressing the ubiquitin-binding-defective OPTN[D477N] mutant. In contrast, IRF3 phosphorylation and IFNβ production were not reduced significantly in BMDM from OPTN[D477N] knockin mice and only reduced partially in TANK KO BMDM. The TLR3/TLR4-dependent phosphorylation of IRF3 and IFNβ gene transcription were not decreased in macrophages from OPTN[D477N] crossed to mice deficient in IκB kinase ε, a TANK-binding kinase related to TBK1. In contrast with the OPTN–TBK1 complex, TBK1 associated with OPTN[D477N] did not undergo phosphorylation at Ser172 in response to poly(I:C) or LPS, indicating that the interaction of ubiquitin chains with OPTN is required to activate OPTN–TBK1 in BMDM. The phosphorylation of IRF3 and IFNβ production induced by Sendai virus infection were unimpaired in BMDM from TANK KO × OPTN[D477N] mice, suggesting that other/additional TBK1 complexes control the RIG-I-like receptor-dependent production of IFNβ. Finally, we present evidence that, in human HACAT cells, the poly(I:C)-dependent phosphorylation of TBK1 at Ser172 involves a novel TBK1-activating kinase(s).

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