scholarly journals Impaired Antiviral Responses to Extracellular Double-Stranded RNA and Cytosolic DNA, but Not to Interferon-α Stimulation, in TRIM56-Deficient Cells

Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 89
Author(s):  
Dang Wang ◽  
Ruixue Wang ◽  
Kui Li
Keyword(s):  
Antiviral Treatment ◽  
Interferon Α ◽  
Type I ◽  
Null Cell ◽  
Double Stranded Rna ◽  
Antiviral Responses ◽  
Bioactivity Assay ◽  
Physiologic Function ◽  
Vesicular Stomatitis ◽  
The Impact

The physiologic function of tripartite motif protein 56 (TRIM56), a ubiquitously expressed E3 ligase classified within the large TRIM protein family, remains elusive. Gene knockdown studies have suggested TRIM56 as a positive regulator of the type I interferon (IFN-I) antiviral response elicited via the Toll-like receptor 3 (TLR3) and cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING) pathways, which detect and respond to danger signals—extracellular double-stranded (ds) RNA and cytosolic dsDNA, respectively. However, to what extent these pathways depend on TRIM56 in human cells is unclear. In addition, it is debatable whether TRIM56 plays a part in controlling the expression of IFN-stimulated genes (ISGs) resulting from IFN-I based antiviral treatment. In this study, we created HeLa-derived TRIM56 null cell lines by gene editing and used these cell models to comprehensively examine the impact of endogenous TRIM56 on innate antiviral responses. Our results showed that TRIM56 knockout severely undermined the upregulation of ISGs by extracellular dsRNA and that loss of TRIM56 weakened the response to cytosolic dsDNA. ISG induction and ISGylation following IFN-α stimulation, however, were not compromised by TRIM56 deletion. Using a vesicular stomatitis virus-based antiviral bioactivity assay, we demonstrated that IFN-α could efficiently establish an antiviral state in TRIM56 null cells, providing direct evidence that TRIM56 is not required for the general antiviral action of IFN-I. Altogether, these data ascertain the contributions of TRIM56 to TLR3- and cGAS–STING-dependent antiviral pathways in HeLa cells and add to our understanding of the roles this protein plays in innate immunity.

scholarly journals N6-methyladenosine RNA modification suppresses antiviral innate sensing pathways via reshaping double-stranded RNA

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weinan Qiu ◽  
Qingyang Zhang ◽  
Rui Zhang ◽  
Yangxu Lu ◽  
Xin Wang ◽  
...  
Keyword(s):  
Rna Virus ◽  
Negative Regulator ◽  
Rna Modification ◽  
Type I ◽  
Viral Immunity ◽  
Potential Therapeutic Target ◽  
Viral Dsrna ◽  
Double Stranded Rna ◽  
Genetic Ablation ◽  
Vesicular Stomatitis

AbstractDouble-stranded RNA (dsRNA) is a virus-encoded signature capable of triggering intracellular Rig-like receptors (RLR) to activate antiviral signaling, but whether intercellular dsRNA structural reshaping mediated by the N6-methyladenosine (m6A) modification modulates this process remains largely unknown. Here, we show that, in response to infection by the RNA virus Vesicular Stomatitis Virus (VSV), the m6A methyltransferase METTL3 translocates into the cytoplasm to increase m6A modification on virus-derived transcripts and decrease viral dsRNA formation, thereby reducing virus-sensing efficacy by RLRs such as RIG-I and MDA5 and dampening antiviral immune signaling. Meanwhile, the genetic ablation of METTL3 in monocyte or hepatocyte causes enhanced type I IFN expression and accelerates VSV clearance. Our findings thus implicate METTL3-mediated m6A RNA modification on viral RNAs as a negative regulator for innate sensing pathways of dsRNA, and also hint METTL3 as a potential therapeutic target for the modulation of anti-viral immunity.

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.

scholarly journals Vesicular stomatitis virus as a flexible platform for oncolytic virotherapy against cancer

2012 ◽  
Vol 93 (12) ◽  
pp. 2529-2545 ◽  
Author(s):  
Eric Hastie ◽  
Valery Z. Grdzelishvili
Keyword(s):  
Cancer Cells ◽  
Vesicular Stomatitis Virus ◽  
Reverse Genetics ◽  
Cell Transformation ◽  
Rna Virus ◽  
Type I ◽  
Delivery Methods ◽  
Recombinant Viruses ◽  
Antiviral Responses ◽  
Vesicular Stomatitis

Oncolytic virus (OV) therapy is an emerging anti-cancer approach that utilizes viruses to preferentially infect and kill cancer cells, while not harming healthy cells. Vesicular stomatitis virus (VSV) is a prototypic non-segmented, negative-strand RNA virus with inherent OV qualities. Antiviral responses induced by type I interferon pathways are believed to be impaired in most cancer cells, making them more susceptible to VSV than normal cells. Several other factors make VSV a promising OV candidate for clinical use, including its well-studied biology, a small, easily manipulated genome, relative independence of a receptor or cell cycle, cytoplasmic replication without risk of host-cell transformation, and lack of pre-existing immunity in humans. Moreover, various VSV-based recombinant viruses have been engineered via reverse genetics to improve oncoselectivity, safety, oncotoxicity and stimulation of tumour-specific immunity. Alternative delivery methods are also being studied to minimize premature immune clearance of VSV. OV treatment as a monotherapy is being explored, although many studies have employed VSV in combination with radiotherapy, chemotherapy or other OVs. Preclinical studies with various cancers have demonstrated that VSV is a promising OV; as a result, a human clinical trial using VSV is currently in progress.

scholarly journals Endogenous mitochondrial double‐stranded RNA is not an activator of the type I interferon response in human pancreatic beta cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexandra Coomans de Brachène ◽  
Angela Castela ◽  
Anyïshai E. Musuaya ◽  
Lorella Marselli ◽  
Piero Marchetti ◽  
...  
Keyword(s):  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Viral Infections ◽  
Human Islets ◽  
Interferon Response ◽  
Interferon Α ◽  
Type I ◽  
Type I Ifn ◽  
Danger Signal ◽  
Double Stranded Rna

Abstract Background Type 1 diabetes (T1D) is an autoimmune disease characterized by the progressive destruction of pancreatic beta cells. Interferon-α (IFNα), an antiviral cytokine, is expressed in the pancreatic islets in early T1D, which may be secondary to viral infections. However, not all patients harboring a type I IFN signature present signals of viral infection, suggesting that this response might be initiated by other “danger signals”. Accumulation of mitochondrial double-stranded RNA (mtdsRNA; a danger signal), secondary to silencing of members of the mitochondrial degradosome, PNPT1 and SUV3, has been described to activate the innate immune response. Methods To evaluate whether mtdsRNA represents a “danger signal” for pancreatic beta cells in the context of T1D, we silenced PNPT1 and/or SUV3 in slowly proliferating human insulin-secreting EndoC-βH1 cells and in non-proliferating primary human beta cells and evaluated dsRNA accumulation by immunofluorescence and the type I IFN response by western blotting and RT-qPCR. Results Only the simultaneous silencing of PNPT1/SUV3 induced dsRNA accumulation in EndoC-βH1 cells but not in dispersed human islets, and there was no induction of a type I IFN response. By contrast, silencing of these two genes individually was enough to induce dsRNA accumulation in fibroblasts present in the human islet preparations. Conclusions These data suggest that accumulation of endogenous mtdsRNA following degradosome knockdown depends on the proliferative capacity of the cells and is not a mediator of the type I IFN response in human pancreatic beta cells.

scholarly journals LGP2 binds to PACT to regulate RIG-I– and MDA5-mediated antiviral responses

2019 ◽  
Vol 12 (601) ◽  
pp. eaar3993 ◽  
Author(s):  
Raul Y. Sanchez David ◽  
Chantal Combredet ◽  
Valérie Najburg ◽  
Gael A. Millot ◽  
Guillaume Beauclair ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Rna Binding ◽  
Inflammatory Responses ◽  
Innate Immune ◽  
Type I ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Protein Protein Interaction ◽  
Antiviral Responses ◽  
Inducible Gene

The retinoic acid–inducible gene I (RIG-I)–like receptors (RLRs) RIG-I, MDA5, and LGP2 stimulate inflammatory and antiviral responses by sensing nonself RNA molecules produced during viral replication. Here, we investigated how LGP2 regulates the RIG-I– and MDA5-dependent induction of type I interferon (IFN) signaling and showed that LGP2 interacted with different components of the RNA-silencing machinery. We identified a direct protein-protein interaction between LGP2 and the IFN-inducible, double-stranded RNA binding protein PACT. The LGP2-PACT interaction was mediated by the regulatory C-terminal domain of LGP2 and was necessary for inhibiting RIG-I–dependent responses and for amplifying MDA5-dependent responses. We described a point mutation within LGP2 that disrupted the LGP2-PACT interaction and led to the loss of LGP2-mediated regulation of RIG-I and MDA5 signaling. These results suggest a model in which the LGP2-PACT interaction regulates the inflammatory responses mediated by RIG-I and MDA5 and enables the cellular RNA-silencing machinery to coordinate with the innate immune response.

scholarly journals Response of Three Different Viruses to Interferon Priming and Dithiothreitol Treatment of Avian Cells

2016 ◽  
Vol 90 (18) ◽  
pp. 8328-8340 ◽  
Author(s):  
Irene Lostalé-Seijo ◽  
José Martínez-Costas ◽  
Javier Benavente
Keyword(s):  
Protein Kinase ◽  
Vaccinia Virus ◽  
Vesicular Stomatitis Virus ◽  
Rna Binding ◽  
Initiation Factor ◽  
Type I ◽  
Avian Reovirus ◽  
Double Stranded Rna ◽  
Vesicular Stomatitis ◽  
Eif2 Phosphorylation

ABSTRACTWe have previously shown that the replication of avian reovirus (ARV) in chicken cells is much more resistant to interferon (IFN) than the replication of vesicular stomatitis virus (VSV) or vaccinia virus (VV). In this study, we have investigated the role that the double-stranded RNA (dsRNA)-activated protein kinase (PKR) plays in the sensitivity of these three viruses toward the antiviral action of chicken interferon. Our data suggest that while interferon priming of avian cells blocks vaccinia virus replication by promoting PKR activation, the replication of vesicular stomatitis virus appears to be blocked at a pretranslational step. Our data further suggest that the replication of avian reovirus in chicken cells is quite resistant to interferon priming because this virus uses strategies to downregulate PKR activation and also because translation of avian reovirus mRNAs is more resistant to phosphorylation of the alpha subunit of initiation factor eIF2 than translation of their cellular counterparts. Our results further reveal that the avian reovirus protein sigmaA is able to prevent PKR activation and that this function is dependent on its double-stranded RNA-binding activity. Finally, this study demonstrates that vaccinia virus and avian reovirus, but not vesicular stomatitis virus, express/induce factors that counteract the ability of dithiothreitol to promote eIF2 phosphorylation. Our data demonstrate that each of the three different viruses used in this study elicits distinct responses to interferon and to dithiothreitol-induced eIF2 phosphorylation when infecting avian cells.IMPORTANCEType I interferons constitute the first barrier of defense against viral infections, and one of the best characterized antiviral strategies is mediated by the double-stranded RNA-activated protein kinase R (PKR). The results of this study revealed that IFN priming of avian cells has little effect on avian reovirus (ARV) replication but drastically diminishes the replication of vaccinia virus (VV) and vesicular stomatitis virus (VSV) by PKR-dependent and -independent mechanisms, respectively. Our data also demonstrate that the dsRNA-binding ability of ARV protein sigmaA plays a key role in the resistance of ARV toward IFN by preventing PKR activation. Our findings will contribute to improve the current understanding of the interaction of viruses with the host's innate immune system. Finally, it would be of interest to uncover the mechanisms that allow avian reovirus transcripts to be efficiently translated under conditions (moderate eIF2 phosphorylation) that block the synthesis of cellular proteins.

scholarly journals TLR7 and TLR8 activate distinct pathways in monocytes during RNA virus infection

2019 ◽  
Vol 12 (605) ◽  
pp. eaaw1347 ◽  
Author(s):  
Marine de Marcken ◽  
Khushwant Dhaliwal ◽  
Ann Caroline Danielsen ◽  
Anne Sophie Gautron ◽  
Margarita Dominguez-Villar
Keyword(s):  
Virus Infection ◽  
Influenza A ◽  
Rna Virus ◽  
White Blood Cells ◽  
Type I ◽  
Human Monocytes ◽  
T Helper ◽  
Antiviral Responses ◽  
Vesicular Stomatitis ◽  
Sense And Respond

Human blood CD14+ monocytes are bone marrow–derived white blood cells that sense and respond to pathogens. Although innate immune activation by RNA viruses preferentially occurs through intracellular RIG-I–like receptors, other nucleic acid recognition receptors, such as Toll-like receptors (TLRs), play a role in finely programming the final outcome of virus infection. Here, we dissected how human monocytes respond to infection with either Coxsackie (CV), encephalomyocarditis (EMCV), influenza A (IAV), measles (MV), Sendai (SV), or vesicular stomatitis (VSV) virus. We found that in monocytes, type I interferon (IFN) and cytokine responses to infection were RNA virus specific and differentially involved TLR7 and TLR8, which sense single-stranded RNA. These TLRs activated distinct signaling cascades in monocytes, which correlated with differences in the production of cytokines involved in the polarization of CD4+ T helper cells. Furthermore, we found that TLR7 signaling specifically increased expression of the transcription factor FOSL1, which reduced IL-27 and TNFα production by monocytes. TLR7, but not TLR8, activation of monocytes also stimulated Ca2+ flux that prevented type I IFN responses. Our work demonstrates that in human monocytes, TLR7 and TLR8 triggered different signaling pathways that contribute to distinct phenotypes during RNA virus infection. In addition, we defined individual targets within these pathways that promoted specific T helper and antiviral responses.

scholarly journals HIPK2 is necessary for type I interferon–mediated antiviral immunity

2019 ◽  
Vol 12 (573) ◽  
pp. eaau4604 ◽  
Author(s):  
Lili Cao ◽  
Guang Yang ◽  
Shandian Gao ◽  
Chunxia Jing ◽  
Ruth R. Montgomery ◽  
...  
Keyword(s):  
Rna Virus ◽  
Antiviral Immunity ◽  
Type I ◽  
Wild Type ◽  
Interacting Protein ◽  
Precise Control ◽  
Antiviral Responses ◽  
Type I Ifns ◽  
Vesicular Stomatitis ◽  
Deficient Mice

Precise control of interferons (IFNs) is crucial to maintain immune homeostasis. Here, we demonstrated that homeodomain-interacting protein kinase 2 (HIPK2) was required for the production of type I IFNs in response to RNA virus infection. HIPK2 deficiency markedly impaired IFN production in macrophages after vesicular stomatitis virus (VSV) infection, and HIPK2-deficient mice were more susceptible to lethal VSV disease than were wild-type mice. After VSV infection, HIPK2 was cleaved by active caspases, which released a hyperactive, N-terminal fragment that translocated to the nucleus and further augmented antiviral responses. In part, HIPK2 interacted with ELF4 and promoted its phosphorylation at Ser369, which enabledIfn-b transcription. In addition, HIPK2 production was stimulated by type I IFNs to further enhance antiviral immunity. These data suggest that the kinase activity and nuclear localization of HIPK2 are essential for the production of type I IFNs.

scholarly journals TRAF-interacting protein (TRIP) negatively regulates IFN-β production and antiviral response by promoting proteasomal degradation of TANK-binding kinase 1

2012 ◽  
Vol 209 (10) ◽  
pp. 1703-1711 ◽  
Author(s):  
Meng Zhang ◽  
Lijuan Wang ◽  
Xueying Zhao ◽  
Kai Zhao ◽  
Hong Meng ◽  
...  
Keyword(s):  
Sendai Virus ◽  
Proteasomal Degradation ◽  
Peritoneal Macrophages ◽  
Negative Regulator ◽  
Type I ◽  
Interacting Protein ◽  
Antiviral Responses ◽  
Enhanced Expression ◽  
Vesicular Stomatitis ◽  
Irf3 Activation

TANK-binding kinase 1 (TBK1) plays an essential role in Toll-like receptor (TLR)– and retinoic acid–inducible gene I (RIG-I)–mediated induction of type I interferon (IFN; IFN-α/β) and host antiviral responses. How TBK1 activity is negatively regulated remains largely unknown. We report that TNF receptor-associated factor (TRAF)–interacting protein (TRIP) promotes proteasomal degradation of TBK1 and inhibits TLR3/4- and RIG-I–induced IFN-β signaling. TRIP knockdown resulted in augmented activation of IFN regulatory factor 3 (IRF3) and enhanced expression of IFN-β in TLR3/4- and RIG-I–activated primary peritoneal macrophages, whereas overexpression of TRIP had opposite effects. Consistently, TRIP impaired Sendai virus (SeV) infection–induced IRF3 activation and IFN-β production and promoted vesicular stomatitis virus (VSV) replication. As an E3 ubiquitin ligase, TRIP negatively regulated the cellular levels of TBK1 by directly binding to and promoting K48-linked polyubiquitination of TBK1. Therefore, we identified TRIP as a negative regulator in TLR3/4- and RIG-I–triggered antiviral responses and suggested TRIP as a potential target for the intervention of diseases with uncontrolled IFN-β production.

scholarly journals Comparative Analysis of Six IRF Family Members in Alveolar Epithelial Cell-Intrinsic Antiviral Responses

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2600
Author(s):  
Sandra Wüst ◽  
Paulina Schad ◽  
Sandy Burkart ◽  
Marco Binder
Keyword(s):  
Alveolar Epithelial Cell ◽  
A549 Cells ◽  
Experimental System ◽  
Alveolar Epithelial Cells ◽  
Type I ◽  
Antiviral State ◽  
Alveolar Epithelial ◽  
Antiviral Responses ◽  
Relative Contribution ◽  
The Impact

Host cell-intrinsic antiviral responses are largely mediated by pattern-recognition receptor (PRR) signaling and the interferon (IFN) system. The IFN regulatory factor (IRF) family of transcription factors takes up a central role in transcriptional regulation of antiviral innate immunity. IRF3 and IRF7 are known to be key players downstream of PRRs mediating the induction of type I and III IFNs. IFN signaling then requires IRF9 for the expression of the full array of interferon stimulated genes (ISGs) ultimately defining the antiviral state of the cell. Other members of the IRF family clearly play a role in mediating or modulating IFN responses, such as IRF1, IRF2 or IRF5, however their relative contribution to mounting a functional antiviral response is much less understood. In this study, we systematically and comparatively assessed the impact of six members of the IRF family on antiviral signaling in alveolar epithelial cells. We generated functional knockouts of IRF1, -2, -3, -5, -7, and -9 in A549 cells, and measured their impact on the expression of IFNs and further cytokines, ISGs and other IRFs, as well as on viral replication. Our results confirmed the vital importance of IRF3 and IRF9 in establishing an antiviral state, whereas IRF1, 5 and 7 were largely dispensable. The previously described inhibitory activity of IRF2 could not be observed in our experimental system.

Sign in / Sign up

Export Citation Format

Share Document