Interferon-Inducible LINC02605 Promotes Antiviral Innate Responses by Strengthening IRF3 Nuclear Translocation

Non-coding RNAs represent a class of important regulators in immune response. Previously, LINC02605 was identified as a candidate regulator in innate immune response by lncRNA microarray assays. In this study, we systematically analyzed the functions and the acting mechanisms of LINC02605 in antiviral innate immune response. LINC02605 was up-regulated by RNA virus, DNA virus, and type I IFNs in NF-κB and Jak-stat dependent manner. Overexpression of LINC02605 promotes RNA virus-induced type I interferon production and inhibited viral replication. Consistently, knockdown of LINC02605 resulted in reduced antiviral immune response and increased viral replication. Mechanistically, LINC02605 released the inhibition of hsa-miR-107 on the expression of phosphatase and tensin homolog (PTEN). By microRNA mimics and inhibitors, hsa-miR-107 was demonstrated to not only inhibit PTEN’s expression but also negatively regulate the antiviral immune response. Knockdown of LINC02605 led to the reduction of PTEN expression both in mRNA and protein levels. Overexpression of LINC02605 had an opposite impact. Moreover, LINC02605 attenuated the serine 97 phosphorylation level of interferon regulatory factor 3 (IRF3) by promoting PTEN expression. Nucleoplasmic fragmentation assay showed that knocking down LINC02605 inhibited the nuclear translocation of IRF3, rendering the host cells more susceptible to viral invasion, while overexpression showed opposite effects. Therefore, LINC02605 is an induced lncRNA by viral infection and plays a positive feedback in antiviral immune response through modulating the nuclear translocation of IRF3.

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Fas-Associated Factor 1 Negatively Regulates the Antiviral Immune Response by Inhibiting Translocation of Interferon Regulatory Factor 3 to the Nucleus

Molecular and Cellular Biology ◽

10.1128/mcb.00744-15 ◽

2016 ◽

Vol 36 (7) ◽

pp. 1136-1151 ◽

Cited By ~ 12

Author(s):

Soonhwa Song ◽

Jae-Jin Lee ◽

Hee-Jung Kim ◽

Jeong Yoon Lee ◽

Jun Chang ◽

...

Keyword(s):

Immune Response ◽

Innate Immune Response ◽

Target Genes ◽

Nuclear Translocation ◽

Antiviral Response ◽

Innate Immune ◽

Type I Interferons ◽

Type I ◽

Antiviral Immune Response ◽

Associated Factor

This study is designed to examine the cellular functions of human Fas-associated factor 1 (FAF1) containing multiple ubiquitin-related domains. Microarray analyses revealed that interferon-stimulated genes related to the antiviral response are significantly increased in FAF1-knockdown HeLa cells. Silencing FAF1 enhanced the poly(I·C)- and respiratory syncytial virus (RSV)-induced production of type I interferons (IFNs), the target genes of interferon regulator factor 3 (IRF3). IRF3 is a key transcription factor in IFN-β signaling responsible for the host innate immune response. This study also found that FAF1 and IRF3 physically associate with IPO5/importin-β3 and that overexpression of FAF1 reduces the interaction between IRF3 and IPO5/importin-β3. These findings suggest that FAF1 negatively regulates IRF3-mediated IFN-β production and the antiviral innate immune response by regulating nuclear translocation of IRF3. We conclude that FAF1 plays a novel role in negatively regulating virus-induced IFN-β production and the antiviral response by inhibiting the translocation of active, phosphorylated IRF3 from the cytosol to the nucleus.

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Sphingolipids in early viral replication and innate immune activation

Biological Chemistry ◽

10.1515/hsz-2018-0181 ◽

2018 ◽

Vol 399 (10) ◽

pp. 1115-1123 ◽

Cited By ~ 7

Author(s):

Judith Bezgovsek ◽

Erich Gulbins ◽

Sarah-Kim Friedrich ◽

Karl S. Lang ◽

Vikas Duhan

Keyword(s):

Immune Response ◽

Viral Replication ◽

Virus Replication ◽

Innate Immune Response ◽

Cell Activation ◽

Killer Cell ◽

Virus Multiplication ◽

Innate Immune ◽

Type I ◽

Antiviral Immune Response

Abstract In this review, we summarize the mechanisms by which sphingolipids modulate virus multiplication and the host innate immune response, using a number of host-virus systems as illustrative models. Sphingolipids exert diverse functions, both at the level of the viral life cycle and in the regulation of antiviral immune responses. Sphingolipids may influence viral replication in three ways: by serving as (co)receptors during viral entry, by modulating virus replication, and by shaping the antiviral immune response. Several studies have demonstrated that sphingosine kinases (SphK) and their product, sphingosine-1-phosphate (S1P), enhance the replication of influenza, measles, and hepatitis B virus (HBV). In contrast, ceramides, particularly S1P and SphK1, influence the expression of type I interferon (IFN-I) by modulating upstream antiviral signaling and enhancing dendritic cell maturation, differentiation, and positioning in tissue. The synthetic molecule α-galactosylceramide has also been shown to stimulate natural killer cell activation and interferon (IFN)-γ secretion. However, to date, clinical trials have failed to demonstrate any clinical benefit for sphingolipids in the treatment of cancer or HBV infection. Taken together, these findings show that sphingolipids play an important and underappreciated role in the control of virus replication and the innate immune response.

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Regulation of the Ebola Virus VP24 Protein by SUMO

Journal of Virology ◽

10.1128/jvi.01687-19 ◽

2019 ◽

Vol 94 (1) ◽

Cited By ~ 6

Author(s):

Santiago Vidal ◽

Ahmed El Motiam ◽

Rocío Seoane ◽

Viktorija Preitakaite ◽

Yanis Hichem Bouzaher ◽

...

Keyword(s):

Immune Response ◽

Innate Immune Response ◽

Viral Protein ◽

Matrix Protein ◽

Ebola Virus ◽

Nuclear Translocation ◽

Critical Role ◽

Innate Immune ◽

Type I ◽

Negative Modulator

ABSTRACT Some viruses take advantage of conjugation of ubiquitin or ubiquitin-like proteins to enhance their own replication. One example is Ebola virus, which has evolved strategies to utilize these modification pathways to regulate the viral proteins VP40 and VP35 and to counteract the host defenses. Here, we show a novel mechanism by which Ebola virus exploits the ubiquitin and SUMO pathways. Our data reveal that minor matrix protein VP24 of Ebola virus is a bona fide SUMO target. Analysis of a SUMOylation-defective VP24 mutant revealed a reduced ability to block the type I interferon (IFN) pathway and to inhibit IFN-mediated STAT1 nuclear translocation, exhibiting a weaker interaction with karyopherin 5 and significantly diminished stability. Using glutathione S-transferase (GST) pulldown assay, we found that VP24 also interacts with SUMO in a noncovalent manner through a SIM domain. Mutation of the SIM domain in VP24 resulted in a complete inability of the protein to downmodulate the IFN pathway and in the monoubiquitination of the protein. We identified SUMO deubiquitinating enzyme ubiquitin-specific-processing protease 7 (USP7) as an interactor and a negative modulator of VP24 ubiquitination. Finally, we show that mutation of one ubiquitination site in VP24 potentiates the IFN modulatory activity of the viral protein and its ability to block IFN-mediated STAT1 nuclear translocation, pointing to the ubiquitination of VP24 as a negative modulator of the VP24 activity. Altogether, these results indicate that SUMO interacts with VP24 and promotes its USP7-mediated deubiquitination, playing a key role in the interference with the innate immune response mediated by the viral protein. IMPORTANCE The Ebola virus VP24 protein plays a critical role in escape of the virus from the host innate immune response. Therefore, deciphering the molecular mechanisms modulating VP24 activity may be useful to identify potential targets amenable to therapeutics. Here, we identify the cellular proteins USP7, SUMO, and ubiquitin as novel interactors and regulators of VP24. These interactions may represent novel potential targets to design new antivirals with the ability to modulate Ebola virus replication.

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Yolkin Isolated from Hen Egg Yolk as a Natural Immunoregulator, Activating Innate Immune Response in BMDM Macrophages

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/5731021 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

W. Kazana ◽

M. Mitkiewicz ◽

M. Ochnik ◽

M. Sochocka ◽

A. Zambrowicz ◽

...

Keyword(s):

Immune Response ◽

Immune System ◽

Innate Immune Response ◽

Egg Yolk ◽

The Body ◽

Innate Immune ◽

Type I ◽

Dependent Manner ◽

Hen Egg Yolk ◽

Hen Egg

One of the goals of biomedical sciences is to search and identify natural compounds that are safe, have no side effects, and possess immunostimulatory activity. It has been proven that medicines of natural origin can be effective agents, supporting the therapy of many diseases, not only in the weakened immune system of the body but also in the prevention of many diseases in healthy people. It has been shown that yolkin, a polypeptide complex isolated from hen egg yolk as a fraction accompanying immunoglobulin Y (IgY), possesses potential biological activity. However, the mechanism of its action has not been explained. The objective of this investigation was to examine the molecular mechanisms of innate immune response, activated in response to yolkin, in murine bone marrow-derived macrophages (BMDM). It was shown that yolkin induced phosphorylation of extracellular signal-kinases (ERK1/2) and c-Jun N-terminal kinase (JNK) and upregulated expression and production of type I interferons, TNF-α (tumor necrosis factor α), and nitric oxide (NO), in BMDM cells. Using pharmacological inhibitors of ERK 1/2 and JNK kinases, we revealed that the JNK signaling cascade is required for yolkin-induced inducible NOS expression and upregulation of NO production in mouse macrophages. Using the TLR4-deficient BMDM cell line, we established that yolkin can activate macrophages in a TLR4-dependent manner. It was also shown that NO, TNF-α, and type I IFNs (α/β) produced by BMDM cells in response to yolkin triggered antiviral activity. These data indicate that yolkin affects the regulation of the immune system and antiviral response; therefore, it can be used as an effective immunostimulator of the innate immunity or as a supplement of the conventional therapy of immunodeficiency.

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Japanese Encephalitis Virus NS5 Inhibits Type I Interferon (IFN) Production by Blocking the Nuclear Translocation of IFN Regulatory Factor 3 and NF-κB

Journal of Virology ◽

10.1128/jvi.00039-17 ◽

2017 ◽

Vol 91 (8) ◽

Cited By ~ 31

Author(s):

Jing Ye ◽

Zheng Chen ◽

Yunchuan Li ◽

Zikai Zhao ◽

Wen He ◽

...

Keyword(s):

Immune Response ◽

Japanese Encephalitis Virus ◽

Innate Immune Response ◽

Nuclear Translocation ◽

Type I Interferon ◽

Transport Proteins ◽

Innate Immune ◽

Type I ◽

Regulatory Factor ◽

Host Innate Immune Response

ABSTRACT The type I interferon (IFN) response is part of the first-line defense against viral infection. To initiate replication, viruses have developed powerful evasion strategies to counteract host IFN responses. In the present study, we found that the Japanese encephalitis virus (JEV) NS5 protein could inhibit double-stranded RNA (dsRNA)-induced IFN-β expression in a dose-dependent manner. Our data further demonstrated that JEV NS5 suppressed the activation of the IFN transcriptional factors IFN regulatory factor 3 (IRF3) and NF-κB. However, there was no defect in the phosphorylation of IRF3 and degradation of IκB, an upstream inhibitor of NF-κB, upon NS5 expression, indicating a direct inhibition of the nuclear localization of IRF3 and NF-κB by NS5. Mechanistically, NS5 was shown to interact with the nuclear transport proteins KPNA2, KPNA3, and KPNA4, which competitively blocked the interaction of KPNA3 and KPNA4 with their cargo molecules, IRF3 and p65, a subunit of NF-κB, and thus inhibited the nuclear translocation of IRF3 and NF-κB. Furthermore, overexpression of KPNA3 and KPNA4 restored the activity of IRF3 and NF-κB and increased the production of IFN-β in NS5-expressing or JEV-infected cells. Additionally, an upregulated replication level of JEV was shown upon KPNA3 or KPNA4 overexpression. These results suggest that JEV NS5 inhibits the induction of type I IFN by targeting KPNA3 and KPNA4. IMPORTANCE JEV is the major cause of viral encephalitis in South and Southeast Asia, with high mortality. However, the molecular mechanisms contributing to the severe pathogenesis are poorly understood. The ability of JEV to counteract the host innate immune response is potentially one of the mechanisms responsible for JEV virulence. Here we demonstrate the ability of JEV NS5 to interfere with the dsRNA-induced nuclear translocation of IRF3 and NF-κB by competitively inhibiting the interaction of IRF3 and NF-κB with nuclear transport proteins. Via this mechanism, JEV NS5 suppresses the induction of type I IFN and the antiviral response in host cells. These findings reveal a novel strategy for JEV to escape the host innate immune response and provide new insights into the pathogenesis of JEV.

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TRIMming Type I Interferon-Mediated Innate Immune Response in Antiviral and Antitumor Defense

Viruses ◽

10.3390/v13020279 ◽

2021 ◽

Vol 13 (2) ◽

pp. 279

Author(s):

Ling Wang ◽

Shunbin Ning

Keyword(s):

Immune Response ◽

Innate Immune Response ◽

Stress Responses ◽

Viral Infections ◽

Immune Escape ◽

E3 Ligase ◽

Innate Immune ◽

Type I ◽

Antiviral Immune Response ◽

Wide Range

The tripartite motif (TRIM) family comprises at least 80 members in humans, with most having ubiquitin or SUMO E3 ligase activity conferred by their N-terminal RING domain. TRIMs regulate a wide range of processes in ubiquitination- or sumoylation-dependent manners in most cases, and fewer as adaptors. Their roles in the regulation of viral infections, autophagy, cell cycle progression, DNA damage and other stress responses, and carcinogenesis are being increasingly appreciated, and their E3 ligase activities are attractive targets for developing specific immunotherapeutic strategies for immune diseases and cancers. Given their importance in antiviral immune response, viruses have evolved sophisticated immune escape strategies to subvert TRIM-mediated mechanisms. In this review, we focus on their regulation of IFN-I-mediated innate immune response, which plays key roles in antiviral and antitumor defense.

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Recognition of HIV-1 capsid licenses innate immune response to viral infection

10.1101/2022.01.10.472699 ◽

2022 ◽

Author(s):

sunnie M yoh ◽

Joao Mamede ◽

Derrick Lau ◽

Narae Ahn ◽

Maria T Sanchez ◽

...

Keyword(s):

Immune Response ◽

Innate Immune Response ◽

Immune Surveillance ◽

Innate Immune ◽

Interferon Response ◽

Type I ◽

Dependent Manner ◽

Dna Viruses ◽

Rna Genome ◽

Hiv 1

Cyclic GMP-AMP synthase (cGAS) is a primary sensor of aberrant DNA that governs an innate immune signaling cascade, leading to the induction of the type-I interferon response. We have previously identified polyglutamine binding protein 1, PQBP1, as an adaptor molecule required for cGAS-mediated innate immune response of lentiviruses, including the human immunodeficiency virus 1 (HIV-1), but dispensable for the recognition of DNA viruses. HIV-1-encoded DNA is synthesized as a single copy from its RNA genome, and is subsequently integrated into the host chromatin. HIV-1 then produces progeny through amplification and packaging of its RNA genome, thus, in contrast to DNA viruses, HIV-1 DNA is both transient and of low abundance. However, the molecular basis for the detection and verification of this low abundance HIV-1 DNA pathogen-associated molecular pattern (PAMP) is not understood. Here, we elucidate a two-factor authentication strategy that is employed by the innate immune surveillance machinery to selectively respond to the low concentration of PAMP, while discerning these species from extranuclear DNA molecules. We find that, upon HIV-1 infection, PQBP1 decorates intact viral capsid, which serves as a primary verification step for the viral nucleic acid cargo. As the reverse transcription and capsid disassembly initiate, cGAS protein is then recruited to the capsid in a PQBP1-dependent manner, enabling cGAS molecules to be co-positioned at the site of PAMP generation. Thus, these data indicate that PQBP1 recognition of the HIV-1 capsid sanctions a robust cGAS-dependent response to a limited abundance and short-lived DNA PAMP. Critically, this illuminates a molecular strategy wherein the modular recruitment of co-factors to germline encoded pattern recognition receptors (PRRs) serves to enhance repertoire of pathogens that can be sensed by the innate immune surveillance machinery.

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The Human Papillomavirus E6 Oncoprotein Targets USP15 and TRIM25 To Suppress RIG-I-Mediated Innate Immune Signaling

Journal of Virology ◽

10.1128/jvi.01737-17 ◽

2017 ◽

Vol 92 (6) ◽

Cited By ~ 28

Author(s):

Cindy Chiang ◽

Eva-Katharina Pauli ◽

Jennifer Biryukov ◽

Katharina F. Feister ◽

Melissa Meng ◽

...

Keyword(s):

Immune Response ◽

Human Papillomavirus ◽

Innate Immune Response ◽

Innate Immune ◽

Signaling Cascade ◽

Type I ◽

Antiviral Immune Response ◽

Hpv16 E6 ◽

E6 Oncoprotein ◽

Hpv16 Infection

ABSTRACTRetinoic acid-inducible gene I (RIG-I) is a key pattern recognition receptor that senses viral RNA and interacts with the mitochondrial adaptor MAVS, triggering a signaling cascade that results in the production of type I interferons (IFNs). This signaling axis is initiated by K63-linked ubiquitination of RIG-I mediated by the E3 ubiquitin ligase TRIM25, which promotes the interaction of RIG-I with MAVS. USP15 was recently identified as an upstream regulator of TRIM25, stabilizing the enzyme through removal of degradative K48-linked polyubiquitin, ultimately promoting RIG-I-dependent cytokine responses. Here, we show that the E6 oncoprotein of human papillomavirus type 16 (HPV16) as well as of other HPV types form a complex with TRIM25 and USP15 in human cells. In the presence of E6, the K48-linked ubiquitination of TRIM25 was markedly increased, and in line with this, TRIM25 degradation was enhanced. Our results further showed that E6 inhibited the TRIM25-mediated K63-linked ubiquitination of RIG-I and its CARD-dependent interaction with MAVS. HPV16 E6, but not E7, suppressed the RIG-I-mediated induction of IFN-β, chemokines, and IFN-stimulated genes (ISGs). Finally, CRISPR-Cas9 gene targeting in human keratinocytes showed that the TRIM25-RIG-I-MAVS triad is important for eliciting an antiviral immune response to HPV16 infection. Our study thus identifies a novel immune escape mechanism that is conserved among different HPV strains and further indicates that the RIG-I signaling pathway plays an important role in the innate immune response to HPV infection.IMPORTANCEPersistent infection and tumorigenesis by HPVs are known to require viral manipulation of a variety of cellular processes, including those involved in innate immune responses. Here, we show that the HPV E6 oncoprotein antagonizes the activation of the cytoplasmic innate immune sensor RIG-I by targeting its upstream regulatory enzymes TRIM25 and USP15. We further show that the RIG-I signaling cascade is important for an antiviral innate immune response to HPV16 infection, providing evidence that RIG-I, whose role in sensing RNA virus infections has been well characterized, also plays a crucial role in the antiviral host response to small DNA viruses of thePapillomaviridaefamily.

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Lymphocytes are detrimental during the early innate immune response against Listeria monocytogenes

Journal of Experimental Medicine ◽

10.1084/jem.20060045 ◽

2006 ◽

Vol 203 (4) ◽

pp. 933-940 ◽

Cited By ~ 99

Author(s):

Javier A. Carrero ◽

Boris Calderon ◽

Emil R. Unanue

Keyword(s):

Immune Response ◽

Listeria Monocytogenes ◽

Innate Immune Response ◽

Early Stage ◽

Bacterial Pathogen ◽

Interleukin 10 ◽

Innate Immune ◽

Type I ◽

Phagocytic Cells ◽

Immunodeficient Mice

Mice deficient in lymphocytes are more resistant than normal mice to Listeria monocytogenes infection during the early innate immune response. This paradox remains unresolved: lymphocytes are required for sterilizing immunity, but their presence during the early stage of the infection is not an asset and may even be detrimental. We found that lymphocyte-deficient mice, which showed limited apoptosis in infected organs, were resistant during the first four days of infection but became susceptible when engrafted with lymphocytes. Engraftment with lymphocytes from type I interferon receptor–deficient (IFN-αβR−/−) mice, which had reduced apoptosis, did not confer increased susceptibility to infection, even when the phagocytes were IFN-αβR+/+. The attenuation of innate immunity was due, in part, to the production of the antiinflammatory cytokine interleukin 10 by phagocytic cells after the apoptotic phase of the infection. Thus, immunodeficient mice were more resistant relative to normal mice because the latter went through a stage of lymphocyte apoptosis that was detrimental to the innate immune response. This is an example of a bacterial pathogen creating a cascade of events that leads to a permissive infective niche early during infection.

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