HIPK2 is necessary for type I interferon–mediated antiviral immunity

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.

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

Journal of Experimental Medicine ◽

10.1084/jem.20060792 ◽

2006 ◽

Vol 203 (7) ◽

pp. 1795-1803 ◽

Cited By ~ 345

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.

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Differential expression and activity of the porcine type I interferon family

Physiological Genomics ◽

10.1152/physiolgenomics.00198.2009 ◽

2010 ◽

Vol 42 (2) ◽

pp. 248-258 ◽

Cited By ~ 58

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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TRIM24 facilitates antiviral immunity through mediating K63-linked TRAF3 ubiquitination

Journal of Experimental Medicine ◽

10.1084/jem.20192083 ◽

2020 ◽

Vol 217 (7) ◽

Cited By ~ 3

Author(s):

Qingchen Zhu ◽

Tao Yu ◽

Shucheng Gan ◽

Yan Wang ◽

Yifei Pei ◽

...

Keyword(s):

Virus Infection ◽

Vesicular Stomatitis Virus ◽

Rna Virus ◽

Antiviral Immunity ◽

Type I ◽

Antiviral Signaling ◽

Unknown Mechanism ◽

Positive Regulator ◽

Transcriptional Suppression ◽

Vesicular Stomatitis

Ubiquitination is an essential mechanism in the control of antiviral immunity upon virus infection. Here, we identify a series of ubiquitination-modulating enzymes that are modulated by vesicular stomatitis virus (VSV). Notably, TRIM24 is down-regulated through direct transcriptional suppression induced by VSV-activated IRF3. Reducing or ablating TRIM24 compromises type I IFN (IFN-I) induction upon RNA virus infection and thus renders mice more sensitive to VSV infection. Mechanistically, VSV infection induces abundant TRIM24 translocation to mitochondria, where TRIM24 binds with TRAF3 and directly mediates K63-linked TRAF3 ubiquitination at K429/K436. This modification of TRAF3 enables its association with MAVS and TBK1, which consequently activates downstream antiviral signaling. Together, these findings establish TRIM24 as a critical positive regulator in controlling the activation of antiviral signaling and describe a previously unknown mechanism of TRIM24 function.

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

Journal of General Virology ◽

10.1099/vir.0.046672-0 ◽

2012 ◽

Vol 93 (12) ◽

pp. 2529-2545 ◽

Cited By ~ 93

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.

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

Science Signaling ◽

10.1126/scisignal.aaw1347 ◽

2019 ◽

Vol 12 (605) ◽

pp. eaaw1347 ◽

Cited By ~ 24

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.

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

Journal of Experimental Medicine ◽

10.1084/jem.20120024 ◽

2012 ◽

Vol 209 (10) ◽

pp. 1703-1711 ◽

Cited By ~ 75

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.

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

Nature Communications ◽

10.1038/s41467-021-21904-y ◽

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.

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Epigenetic regulation of frog innate immunity: Discovery of frog microRNAs associated with antiviral responses and ranavirus infection using a Xenopus laevis skin epithelial-like cell line

10.1101/2021.06.29.450442 ◽

2021 ◽

Author(s):

Lauren A. Todd ◽

Maxwell P. Bui-Marinos ◽

Barbara A. Katzenback

Keyword(s):

Xenopus Laevis ◽

Cell Line ◽

Antiviral Immunity ◽

Type I Interferons ◽

Poly I:C ◽

Type I ◽

Frog Virus ◽

Interferon Stimulated Genes ◽

Antiviral Responses ◽

Innate Antiviral Immunity

Epigenetic regulators such as microRNAs are emerging as conserved regulators of innate antiviral immunity in vertebrates, yet their roles in amphibian antiviral responses remain uncharacterized. We profiled changes in microRNA expressions in the Xenopus laevis skin epithelial–like cell line Xela DS2 in response to poly(I:C) – an analogue of double-stranded viral RNA and inducer of type I interferons – or frog virus 3 (FV3), an immunoevasive virus associated with amphibian mortality events. We sequenced small RNA libraries generated from untreated, poly(I:C)–treated, and FV3–infected cells. We detected 136 known X. laevis microRNAs and discovered 133 novel X. laevis microRNAs. Sixty–five microRNAs were differentially expressed in response to poly(I:C), many of which were predicted to target regulators of antiviral pathways such as cGAS–STING, RIG–I/MDA–5, TLR signaling, and type I interferon signaling, as well as products of these pathways (NF–κB–induced and interferon-stimulated genes). In contrast, only 49 microRNAs were altered by FV3 infection, fewer of which were predicted to interact with antiviral pathways. Interestingly, poly(I:C) treatment or FV3 infection downregulated transcripts encoding factors of the host microRNA biogenesis pathway. Our study is the first to suggest that host microRNAs regulate innate antiviral immunity in frogs, and sheds light on microRNA–mediated mechanisms of immunoevasion by FV3.

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An arms race: innate antiviral responses and counteracting viral strategies

Biochemical Society Transactions ◽

10.1042/bst0351512 ◽

2007 ◽

Vol 35 (6) ◽

pp. 1512-1514 ◽

Cited By ~ 21

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.

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

Viruses ◽

10.3390/v14010089 ◽

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.

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