3D, a Novel Mutation That Confers Defective Sensing by Toll-Like Receptors 3, 7 and 9.

Abstract The mammalian Toll-like receptors (TLRs) comprise a key interface between cells of the host and all classes of microbial pathogen. By sensing nucleic acids, the endosomal TLRs 3, 7, and 9 play a particularly important role in the detection of viral infection, and permit the host to mount an immediate and efficacious anti-viral response. In an effort to identify novel components of the TLR signaling apparatus, we have pursued a program of germline saturation mutagenesis with N-ethyl-N-nitrosourea (ENU) in mice. The germline mutants are produced on the C57BL/6 background, and peritoneal macrophages from individual animals are screened for their competence to respond to TLR-dependent microbial inducers. A strong phenodeviant called 3d was identified in the F3 generation as a non-responder to nucleoside-based molecules such as unmethylated CpG oligodeoxynucleotides, Resiquimod (a drug of the imidazoquinoline class) and Poly I:C. TNFa production induced by TLRs 3, 7, and 9 was completely prevented in 3d homozygotes. However, heterozygotes were unaffected, and the ability to produce TNFa in response to other bacterial compounds, sensed by TLRs 1, 2, 4, and 6, was intact. 3d homozygotes show extreme susceptibility to infection by mouse cytomegalovirus (MCMV) infection in vivo. After IP inoculation with MCMV (104 PFU), 3d mutants showed impaired production of type I and type II interferons, TNF, and IL-12 in serum (p<0.001). With larger inocula (5 x 105 PFU) a splenic viral titer approximately ten-thousand fold higher than that in controls (p<0.05) and rapid mortality (p<0.0001) were observed. This novel recessive phenotype is fully penetrant on the C57BL/6 and C3H/HeN x C57BL/6 hybrid backgrounds. The 3d mutation was mapped to mouse chromosome 19 using a panel of microsatellite markers and at present, has been confined to 0.4 a Mbp critical region on 3000 meioses. 3d appears to encode a protein essential for TLR-mediated detection of nucleic acids, which is indispensable for effective innate defense against viral infection.

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Type I interferons act directly on nociceptors to produce pain sensitization: Implications for viral infection-induced pain

10.1101/2019.12.27.889568 ◽

2019 ◽

Author(s):

Paulino Barragan-Iglesias ◽

Úrzula Franco-Enzástiga ◽

Vivekanand Jeevakumar ◽

Andi Wangzhou ◽

Vinicio Granados-Soto ◽

...

Keyword(s):

Viral Infection ◽

Viral Infections ◽

Mrna Translation ◽

Type I Interferons ◽

Poly I:C ◽

Type I ◽

Drg Neurons ◽

Pain Hypersensitivity ◽

Type I Ifns ◽

Pain Sensitization

ABSTRACTOne of the first signs of viral infection is body-wide aches and pain. While this type of pain usually subsides, at the extreme, viral infections can induce painful neuropathies that can last for decades. Neither of these types of pain sensitization are well understood. A key part of the response to viral infection is production of interferons (IFNs), which then activate their specific receptors (IFNRs) resulting in downstream activation of cellular signaling and a variety of physiological responses. We sought to understand how type I IFNs (IFN-α and IFN-β) might act directly on nociceptors in the dorsal root ganglion (DRG) to cause pain sensitization. We demonstrate that type I IFNRs are expressed in small/medium DRG neurons and that their activation produces neuronal hyper-excitability and mechanical pain in mice. Type I IFNs stimulate JAK/STAT signaling in DRG neurons but this does not apparently result in PKR-eIF2α activation that normally induces an anti-viral response by limiting mRNA translation. Rather, type I interferons stimulate MNK-mediated eIF4E phosphorylation in DRG neurons to promote pain hypersensitivity. Endogenous release of type I IFNs with the double stranded RNA mimetic poly(I:C) likewise produces pain hypersensitivity that is blunted in mice lacking MNK-eIF4E signaling. Our findings reveal mechanisms through which type I IFNs cause nociceptor sensitization with implications for understanding how viral infections promote pain and can lead to neuropathies.SIGNIFICANCE STATEMENTIt is increasingly understood that pathogens interact with nociceptors to alert organisms to infection as well as to mount early host defenses. While specific mechanisms have been discovered for diverse bacteria and fungal pathogens, mechanisms engaged by viruses have remained elusive. Here we show that type 1 interferons, one of the first mediators produced by viral infection, act directly on nociceptors to produce pain sensitization. Type I interferons act via a specific signaling pathway (MNK-eIF4E signaling) that is known to produce nociceptor sensitization in inflammatory and neuropathic pain conditions. Our work reveals a mechanism through which viral infections cause heightened pain sensitivity

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Functional Roles of Pattern Recognition Receptors That Recognize Virus Nucleic Acids in Human Adipose-Derived Mesenchymal Stem Cells

BioMed Research International ◽

10.1155/2016/9872138 ◽

2016 ◽

Vol 2016 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Lili Yu ◽

Yongtao Xu ◽

Fangchao Wang ◽

Can Yang ◽

Guoyan Liu ◽

...

Keyword(s):

Stem Cells ◽

Pattern Recognition ◽

Mesenchymal Stem Cells ◽

Immune Responses ◽

Nucleic Acids ◽

Pattern Recognition Receptors ◽

Poly I:C ◽

Type I ◽

Oligoadenylate Synthetase ◽

Viral Dna

Human adipose-derived mesenchymal stem cells (hAD-MSCs) are mesenchymal stem cells with the capability to modulate immune responses. Evidence showing that hAD-MSCs could mediate innate immune responses through pattern recognition receptors (PRRs) is increasing. However, the roles of PRRs in regulating the innate sensing of virus nucleic acids (RNA and DNA) in hAD-MSCs have not yet been investigated. This study focused on the abundant expression of PRRs, including Toll-like receptor 3 (TLR3) and retinoic acid-inducible gene I (RIG-I), which recognize viral RNA, and gamma-interferon inducible protein 16 (IFI16), which recognizes viral DNA in hAD-MSCs. Poly(I:C), a synthetic dsRNA analogy, activated TLR3 and RIG-I and induced the expression of type I interferons (IFN-α/β) and antivirus proteins, including IFN-stimulating gene 15, 2′5′-oligoadenylate synthetase, and Mx GTPase 1 in hAD-MSCs, which were attenuated by the knockdown of each TLR3 or RIG-I. Synthetic herpes simplex viral DNA (HSV60) activated IFI16 and induced the expression of IFN-α/β and antivirus proteins in hAD-MSCs, which were inhibited by the knockdown of IFI16. Both poly(I:C) and HSV60 induced the expression of IFN-α/β through the phosphorylation of IFN-regulatory factor 3. All these results indicated that PRRs recognizing virus nucleic acids were expressed and can mediate antivirus responses in hAD-MSCs.

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Double-Stranded RNA Acts as a Strong Danger Signal in Human Myeloid Leukemia Cells Leading to Increased Immunogenicity.

Blood ◽

10.1182/blood.v108.11.5203.5203 ◽

2006 ◽

Vol 108 (11) ◽

pp. 5203-5203

Author(s):

Zwi N. Berneman ◽

Evelien L.J.M. Smits ◽

Peter Ponsaerts ◽

Nathalie Cools ◽

Ann L.R. Van de Velde ◽

...

Keyword(s):

Dendritic Cells ◽

Dendritic Cell ◽

Viral Infection ◽

Myeloid Leukemia ◽

Costimulatory Molecules ◽

T Cell Response ◽

Leukemic Cells ◽

Poly I:C ◽

Type I ◽

Tlr3 Expression

Abstract Leukemic cells exert immunosuppressive effects that interfere with dendritic cell function and hamper effective anti-leukemic immune responses. Recently, Toll-like receptor 3 (TLR3) was characterized in dendritic cells as an intracellular double-stranded (ds)RNA receptor which is triggered by viral infection or incubation with the synthetic dsRNA analogue polyriboinosinic polyribocytidylic acid [poly(I:C)], leading to maturation and activation of dendritic cells. Until now, little was known on the expression of TLR3 in leukemic cells and their responsiveness to dsRNA treatment. We assessed TLR3 expression in primary and transformed acute myeloid leukemia (AML) cells and hypothesized that the immunogenicity of AML cells could be improved by treatment with the synthetic TLR3 agonist poly(I:C), thereby mimicking viral infection of these leukemic cells. In view of this hypothesis, we electroporated or pulsed transformed and primary AML cells with poly(I:C) and analyzed the effect of poly(I:C) loading on TLR3 expression, costimulatory molecules, cytokine production and allogeneic T cell response. We also assessed the uptake of poly(I:C)-loaded leukemic cells by immature dendritic cells and the subsequent effect on dendritic cell activation and maturation status. We observed that primary and transformed AML cells respond to poly(I:C) electroporation by upregulation of TLR3 expression, apoptosis, elevated levels of costimulatory molecules CD80 and CD86 and by production of type I interferons (IFN). Furthermore, poly(I:C)-electroporated AML cells induced interferon-gamma production by allogeneic T cells. Upon phagocytosis of poly(I:C)-electroporated AML cells, dendritic cells showed an increased expression of maturation markers and marked production of proinflammatory cytokines. In contrast, this set of immune effects was absent or suboptimal when AML cells were passively pulsed with poly(I:C), indicating the superiority of transfection over pulsing with poly(I:C). These results demonstrate that poly(I:C) electroporation is a promising novel strategy to increase the immunogenicity of AML cells.

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Type I IFN promotes NK cell expansion during viral infection by protecting NK cells against fratricide

Journal of Experimental Medicine ◽

10.1084/jem.20150712 ◽

2016 ◽

Vol 213 (2) ◽

pp. 225-233 ◽

Cited By ~ 78

Author(s):

Sharline Madera ◽

Moritz Rapp ◽

Matthew A. Firth ◽

Joshua N. Beilke ◽

Lewis L. Lanier ◽

...

Keyword(s):

Viral Infection ◽

Nk Cells ◽

Nk Cell ◽

Cell Formation ◽

Memory Cell ◽

Type I ◽

Dependent Manner ◽

Type I Ifn ◽

Mcmv Infection ◽

Adaptive Immune Cells

Type I interferon (IFN) is crucial in host antiviral defense. Previous studies have described the pleiotropic role of type I IFNs on innate and adaptive immune cells during viral infection. Here, we demonstrate that natural killer (NK) cells from mice lacking the type I IFN-α receptor (Ifnar−/−) or STAT1 (which signals downstream of IFNAR) are defective in expansion and memory cell formation after mouse cytomegalovirus (MCMV) infection. Despite comparable proliferation, Ifnar−/− NK cells showed diminished protection against MCMV infection and exhibited more apoptosis compared with wild-type NK cells. Furthermore, we show that Ifnar−/− NK cells express increased levels of NK group 2 member D (NKG2D) ligands during viral infection and are susceptible to NK cell–mediated fratricide in a perforin- and NKG2D-dependent manner. Adoptive transfer of Ifnar−/− NK cells into NK cell–deficient mice reverses the defect in survival and expansion. Our study reveals a novel type I IFN–dependent mechanism by which NK cells evade mechanisms of cell death after viral infection.

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Astrocyte Control of Zika Infection Is Independent of Interferon Type I and Type III Expression

Biology ◽

10.3390/biology11010143 ◽

2022 ◽

Vol 11 (1) ◽

pp. 143

Author(s):

Mithun Das ◽

Monique L. Smith ◽

Tomomi Furihata ◽

Subir Sarker ◽

Ross O’Shea ◽

...

Keyword(s):

Viral Infection ◽

Neurological Complications ◽

Poly I:C ◽

Type I ◽

Infection Level ◽

Antiviral Genes ◽

Tnf Α ◽

The Central Nervous System ◽

Efficient Protection ◽

Antiviral Gene

Zika virus (ZIKV) is a pathogenic neurotropic virus that infects the central nervous system (CNS) and results in various neurological complications. Astrocytes are the dominant CNS cell producer of the antiviral cytokine IFN-β, however little is known about the factors involved in their ability to mediate viral infection control. Recent studies have displayed differential responses in astrocytes to ZIKV infection, and this study sought to elucidate astrocyte cell-specific responses to ZIKV using a variety of cell models infected with either the African (MR766) or Asian (PRVABC59) ZIKV strains. Expression levels of pro-inflammatory (TNF-α and IL-1β) and inflammatory (IL-8) cytokines following viral infection were low and mostly comparable within the ZIKV-resistant and ZIKV-susceptible astrocyte models, with better control of proinflammatory cytokines displayed in resistant astrocyte cells, synchronising with the viral infection level at specific timepoints. Astrocyte cell lines displaying ZIKV-resistance also demonstrated early upregulation of multiple antiviral genes compared with susceptible astrocytes. Interestingly, pre-stimulation of ZIKV-susceptible astrocytes with either poly(I:C) or poly(dA:dT) showed efficient protection against ZIKV compared with pre-stimulation with either recombinant IFN-β or IFN-λ, perhaps indicating that a more diverse antiviral gene expression is necessary for astrocyte control of ZIKV, and this is driven in part through interferon-independent mechanisms.

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NUDT21 links mitochondrial IPS-1 to RLR-containing stress granules and activates host antiviral defense

10.1101/2020.04.09.033597 ◽

2020 ◽

Author(s):

Saeko Aoyama-Ishiwatari ◽

Tomohiko Okazaki ◽

Shun-ichiro Iemura ◽

Tohru Natsume ◽

Yasushi Okada ◽

...

Keyword(s):

Viral Infection ◽

Host Defense ◽

Rna Binding ◽

Adaptor Protein ◽

Stress Granules ◽

Host Cells ◽

Poly I:C ◽

Mammalian Host ◽

Type I ◽

Resting Cells

SummaryViral RNA in the cytoplasm of mammalian host cells is recognized by retinoic acid– inducible protein–I (RIG-I)–like receptors (RLRs), which localize to cytoplasmic stress granules (SGs). Activated RLRs associate with the mitochondrial adaptor protein IPS-1, which activates antiviral host defense mechanisms including type I interferon (IFN) induction. It has remained unclear, however, how RLRs in SGs and IPS-1 in the mitochondrial outer membrane associate physically and engage in information transfer. Here we show that NUDT21, an RNA binding protein that regulates alternative transcript polyadenylation, physically associates with IPS-1 and mediates its localization to SGs in response to transfection with poly(I:C), a mimic of viral double-stranded RNA. We found that, despite its well-established function in the nucleus, a fraction of NUDT21 localizes to mitochondria in resting cells and becomes localized to SGs in response to poly(I:C) transfection. NUDT21 was also found to be required for efficient type I IFN induction in response to viral infection. Our results together indicate that NUDT21 links RLRs in SGs to mitochondrial IPS-1 and thereby activates host defense responses to viral infection.

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