An arms race: innate antiviral responses and counteracting viral strategies

2007 ◽  
Vol 35 (6) ◽  
pp. 1512-1514 ◽  
Author(s):  
M. Schröder ◽  
A.G. Bowie
Keyword(s):  
Nuclear Factor Κb ◽  
Signalling Pathways ◽  
Type I ◽  
Nuclear Factor ◽  
Regulatory Factor ◽  
Antiviral Responses ◽  
Type I Ifns ◽  
Activation Of Transcription ◽  
Molecular Patterns ◽  
Pro Inflammatory Cytokines

Viral recognition is mediated by different classes of PRRs (pattern-recognition receptors) among which the TLRs (Toll-like receptors) and the RLHs [RIG (retinoic-acid-inducible)-like helicases] play major roles. The detection of PAMPs (pathogen-associated molecular patterns) by these PRRs leads to the initiation of signalling pathways that ultimately result in the activation of transcription factors such as NF-κB (nuclear factor κB) and IRF-3 [IFN (interferon) regulatory factor-3] and IRF-7 and the induction of pro-inflammatory cytokines and type I IFNs. Viruses have evolved a fine-tuned mechanism to evade detection by the immune system or to interfere with the resulting signalling pathways. Here, we discuss viral evasion proteins that specifically interfere with TLR and/or RLH signalling.

scholarly journals DDX3 directly facilitates IKKα activation and regulates downstream signalling pathways

2018 ◽  
Vol 475 (22) ◽  
pp. 3595-3607 ◽  
Author(s):  
Anthony Fullam ◽  
Lili Gu ◽  
Yvette Höhn ◽  
Martina Schröder
Keyword(s):  
Nuclear Factor Κb ◽  
Innate Immune ◽  
Type I Interferons ◽  
Signalling Pathways ◽  
Type I ◽  
Nuclear Factor ◽  
Toll Like Receptor ◽  
Disease States ◽  
Dead Box ◽  
Iκb Kinase

DDX3 is a DEAD-box RNA helicase that we and others have previously implicated in antiviral immune signalling pathways leading to type I interferon (IFN) induction. We previously demonstrated that it directly interacts with the kinase IKKε (IκB kinase ε), enhances it activation, and then facilitates phosphorylation of the transcription factor IRF3 by IKKε. However, the TLR7/9 (Toll-like receptor 7/9)-mediated pathway, one of the most physiologically relevant IFN induction pathways, proceeds independently of IKKε or the related kinase TBK1 (TANK-binding kinase 1). This pathway induces type I IFN production via the kinases NIK (NF-κB-inducing kinase) and IKKα and is activated when plasmacytoid dendritic cells sense viral nucleic acids. In the present study, we demonstrate that DDX3 also directly interacts with IKKα and enhances its autophosphorylation and -activation. Modulation of DDX3 expression consequently affected NIK/IKKα-mediated IRF7 phosphorylation and induction of type I interferons. In addition, alternative NF-κB (nuclear factor-κB) activation, another pathway regulated by NIK and IKKα, was also down-regulated in DDX3 knockdown cells. This substantially broadens the effects of DDX3 in innate immune signalling to pathways beyond TBK1/IKKε and IFN induction. Dysregulation of these pathways is involved in disease states, and thus, our research might implicate DDX3 as a potential target for their therapeutic manipulation.

Targeting IRFs by ubiquitination: regulating antiviral responses

2008 ◽  
Vol 36 (3) ◽  
pp. 453-458 ◽  
Author(s):  
Rowan Higgs ◽  
Caroline A. Jefferies
Keyword(s):  
Transcription Factors ◽  
Viral Infection ◽  
Viral Proteins ◽  
Interferon Regulatory Factor ◽  
Type I ◽  
Regulatory Factor ◽  
Ubiquitin Pathway ◽  
Cellular Processes ◽  
Antiviral Responses ◽  
Type I Ifns

The IRF [IFN (interferon) regulatory factor] family of transcription factors control many cellular processes, including induction of key antiviral cytokines, type I IFNs, following viral infection. Recent studies have revealed several endogenous and viral proteins involved in ubiquitin-mediated regulation of IRF activity and thus having an impact on type I IFN signalling. Through the ubiquitin pathway, these proteins can manipulate the antiviral response either by initiating proteasomal degradation of the IRFs or, in contrast, by promoting activation of the IRFs.

scholarly journals Acer tataricum subsp. ginnala Inhibits Skin Photoaging via Regulating MAPK/AP-1, NF-κB, and TGFβ/Smad Signaling in UVB-Irradiated Human Dermal Fibroblasts

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 662
Author(s):  
Yu-Jung Jin ◽  
Yura Ji ◽  
Young-Pyo Jang ◽  
Se-Young Choung
Keyword(s):  
Collagen Synthesis ◽  
Nuclear Factor Κb ◽  
Dermal Fibroblasts ◽  
Type I ◽  
Nuclear Factor ◽  
Human Dermal Fibroblasts ◽  
Smad Pathway ◽  
Type I Procollagen ◽  
Skin Photoaging ◽  
Pro Inflammatory Cytokines

Skin, the organ protecting the human body from external factors, maintains structural and tensile strength by containing many collagen fibrils, particularly type I procollagen. However, oxidative stress by ultraviolet (UV) exposure causes skin photoaging by activating collagen degradation and inhibiting collagen synthesis. Acer tataricum subsp. ginnala extract (AGE) is a herbal medicine with anti-inflammatory and anti-oxidative effects, but there is no report on the protective effect against skin photoaging. Therefore, we conducted research concentrating on the anti-photoaging effect of Acer tataricum subsp. ginnala (AG) in UVB (20 mJ/cm2)-irradiated human dermal fibroblasts (HDF). Then, various concentrations (7.5, 15, 30 µg/mL) of AGE were treated in HDF for 24 h following UVB irradiation. After we performed AGE treatment, the matrix metalloproteinase1 (MMP1) expression was downregulated, and the type I procollagen level was recovered. Then, we investigated the mitogen-activated protein kinases/activator protein 1 (MAPK/AP-1) and nuclear factor-κB (NF-κB) pathway, which induce collagen breakdown by promoting the MMP1 level and pro-inflammatory cytokines. The results indicated that AGE downregulates the expression of the MAPK/AP-1 pathway, leading to MMP1 reduction. AGE inhibits nuclear translocation of NF-κB and inhibitor of nuclear factor-κB (IκB) degradation. Therefore, it downregulates the expression of MMP1 and pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 increased by UVB. Besides, the TGFβ/Smad pathway, which is mainly responsible for the collagen synthesis in the skin, was also analyzed. AGE decreases the expression of Smad7 and increases TGFβRII expression and Smad3 phosphorylation. This means that AGE stimulates the TGFβ/Smad pathway that plays a critical role in promoting collagen synthesis. Thus, this study suggests that AGE can be a functional material with anti-photoaging properties.

scholarly journals Essential role of IPS-1 in innate immune responses against RNA viruses

2006 ◽  
Vol 203 (7) ◽  
pp. 1795-1803 ◽  
Author(s):  
Himanshu Kumar ◽  
Taro Kawai ◽  
Hiroki Kato ◽  
Shintaro Sato ◽  
Ken Takahashi ◽  
...  
Keyword(s):  
Rna Viruses ◽  
Rna Virus ◽  
Critical Role ◽  
Nuclear Factor Κb ◽  
Type I ◽  
Innate Immune Responses ◽  
Antiviral Responses ◽  
Deficient Mice

IFN-β promoter stimulator (IPS)-1 was recently identified as an adapter for retinoic acid–inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (Mda5), which recognize distinct RNA viruses. Here we show the critical role of IPS-1 in antiviral responses in vivo. IPS-1–deficient mice showed severe defects in both RIG-I– and Mda5-mediated induction of type I interferon and inflammatory cytokines and were susceptible to RNA virus infection. RNA virus–induced interferon regulatory factor-3 and nuclear factor κB activation was also impaired in IPS-1–deficient cells. IPS-1, however, was not essential for the responses to either DNA virus or double-stranded B-DNA. Thus, IPS-1 is the sole adapter in both RIG-I and Mda5 signaling that mediates effective responses against a variety of RNA viruses.

scholarly journals Effects of Onchung-eum, an Herbal Prescription, on 5-Fluorouracil–Induced Oral Mucositis

2018 ◽  
Vol 17 (4) ◽  
pp. 1285-1296
Author(s):  
Jae-Woo Park ◽  
Jayoung Oh ◽  
Seok-Jae Ko ◽  
Mun Seog Chang ◽  
Jinsung Kim
Keyword(s):  
Inflammatory Cytokines ◽  
Oral Mucositis ◽  
Caspase 3 ◽  
Skin Diseases ◽  
Nuclear Factor Κb ◽  
Control Group ◽  
Nuclear Factor ◽  
Cheek Pouches ◽  
Herbal Prescription ◽  
Pro Inflammatory Cytokines

In most cancer patients, chemotherapy-induced oral mucositis (OM) is a frequent side effect, leading to low quality of life and delay in therapy. The aim of this study was to evaluate the effects of Onchung-eum, a well-known herbal prescription in traditional medicine comprising 8 herbs that has long been used for skin diseases, on 5-fluorouracil (5-FU)–induced OM in human pharyngeal cells and golden Syrian hamsters. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and reactive oxygen species production were measured in vitro. The effects of Onchung-eum on OM of hamster cheek pouches induced by 5-FU were evaluated histologically and using TUNEL assay. In addition, the expression of nuclear factor-κB, caspase-3, and pro-inflammatory cytokines were measured by immunoblotting and immunohistochemistry. Significantly increased cell viability was observed in the Onchung-eum–treated groups compared with the 5-FU–treated control group. In 500 and 1000 mg/kg Onchung-eum–treated groups, the damaged epithelial layers in the cheek pouches of hamsters were significantly recovered. Moreover, at all concentrations, cell death in the cheek pouches of hamsters in the Onchung-eum–treated groups significantly decreased. The expression of pro-inflammatory cytokines, nuclear factor-κB, and caspase-3 also significantly decreased in Onchung-eum–treated groups at 500 and 1000 mg/kg. In conclusion, this study revealed that Onchung-eum can be used to treat chemotherapy-induced OM. However, further studies are required to understand the underlying mechanisms.

scholarly journals IFN Regulatory Factor 3-Dependent Induction of Type I IFNs by Intracellular Bacteria Is Mediated by a TLR- and Nod2-Independent Mechanism

2004 ◽  
Vol 173 (12) ◽  
pp. 7416-7425 ◽  
Author(s):  
Silvia Stockinger ◽  
Benjamin Reutterer ◽  
Barbara Schaljo ◽  
Carola Schellack ◽  
Sylvia Brunner ◽  
...  
Keyword(s):  
Intracellular Bacteria ◽  
Type I ◽  
Regulatory Factor ◽  
Type I Ifns ◽  
Independent Mechanism

scholarly journals The Role of miR-21 in Osteoblasts–Osteoclasts Coupling In Vitro

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 479 ◽  
Author(s):  
Agnieszka Smieszek ◽  
Klaudia Marcinkowska ◽  
Ariadna Pielok ◽  
Mateusz Sikora ◽  
Lukas Valihrach ◽  
...  
Keyword(s):  
Cathepsin K ◽  
Nuclear Factor Κb ◽  
Tartrate Resistant Acid Phosphatase ◽  
Type I ◽  
Nuclear Factor ◽  
Paracrine Signaling ◽  
Receptor Activator ◽  
The Impact

MiR-21 is being gradually more and more recognized as a molecule regulating bone tissue homeostasis. However, its function is not fully understood due to the dual role of miR-21 on bone-forming and bone-resorbing cells. In this study, we investigated the impact of miR-21 inhibition on pre-osteoblastic cells differentiation and paracrine signaling towards pre-osteoclasts using indirect co-culture model of mouse pre-osteoblast (MC3T3) and pre-osteoclast (4B12) cell lines. The inhibition of miR-21 in MC3T3 cells (MC3T3inh21) modulated expression of genes encoding osteogenic markers including collagen type I (Coll-1), osteocalcin (Ocl), osteopontin (Opn), and runt-related transcription factor 2 (Runx-2). Inhibition of miR-21 in osteogenic cultures of MC3T3 also inflected the synthesis of OPN protein which is essential for proper mineralization of extracellular matrix (ECM) and anchoring osteoclasts to the bones. Furthermore, it was shown that in osteoblasts miR-21 regulates expression of factors that are vital for survival of pre-osteoclast, such as receptor activator of nuclear factor κB ligand (RANKL). The pre-osteoclast cultured with MC3T3inh21 cells was characterized by lowered expression of several markers associated with osteoclasts’ differentiation, foremost tartrate-resistant acid phosphatase (Trap) but also receptor activator of nuclear factor-κB ligand (Rank), cathepsin K (Ctsk), carbonic anhydrase II (CaII), and matrix metalloproteinase (Mmp-9). Collectively, our data indicate that the inhibition of miR-21 in MC3T3 cells impairs the differentiation and ECM mineralization as well as influences paracrine signaling leading to decreased viability of pre-osteoclasts.

Differential expression and activity of the porcine type I interferon family

2010 ◽  
Vol 42 (2) ◽  
pp. 248-258 ◽  
Author(s):  
Yongming Sang ◽  
Raymond R. R. Rowland ◽  
Richard A. Hesse ◽  
Frank Blecha
Keyword(s):  
Antiviral Activity ◽  
Expression Profiles ◽  
Type I Interferons ◽  
Respiratory Syndrome Virus ◽  
Target Cells ◽  
Type I ◽  
Antiviral Responses ◽  
Type I Ifns ◽  
Antiviral Activities ◽  
Vesicular Stomatitis

Type I interferons (IFNs) are central to innate and adaptive immunity, and many have unique developmental and physiological functions. However, in most species, only two subtypes, IFN-α and IFN-β, have been well studied. Because of the increasing importance of zoonotic viral diseases and the use of pigs to address human research questions, it is important to know the complete repertoire and activity of porcine type I IFNs. Here we show that porcine type I IFNs comprise at least 39 functional genes distributed along draft genomic sequences of chromosomes 1 and 10. These functional IFN genes are classified into 17 IFN-α subtypes, 11 IFN-δ subtypes, 7 IFN-ω subtypes, and single-subtype subclasses of IFN-αω, IFN-β, IFN-ε, and IFN-κ. We found that porcine type I IFNs have diverse expression profiles and antiviral activities against porcine reproductive and respiratory syndrome virus (PRRSV) and vesicular stomatitis virus (VSV), with activity ranging from 0 to >105 U·ng−1·ml−1. Whereas most IFN-α subtypes retained the greatest antiviral activity against both PRRSV and VSV in porcine and MARC-145 cells, some IFN-δ and IFN-ω subtypes, IFN-β, and IFN-αω differed in their antiviral activity based on target cells and viruses. Several IFNs, including IFN-α7/11, IFN-δ2/7, and IFN-ω4, exhibited minimal or no antiviral activity in the tested target cell-virus systems. Thus comparative studies showed that antiviral activity of porcine type I IFNs is virus- and cell-dependent, and IFN-αs are positively correlated with induction of MxA, an IFN-stimulated gene. Collectively, these data provide fundamental genomic information for porcine type I IFNs, information that is necessary for understanding porcine physiological and antiviral responses.

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