scholarly journals Zebrafish RPZ5 Degrades Phosphorylated IRF7 To Repress Interferon Production

2019 ◽  
Vol 93 (21) ◽  
Author(s):  
Long-Feng Lu ◽  
Xiao-Yu Zhou ◽  
Can Zhang ◽  
Zhuo-Cong Li ◽  
Dan-Dan Chen ◽  
...  
Keyword(s):  
Viral Infection ◽  
Host Cell ◽  
Negative Regulator ◽  
Regulatory Factor ◽  
Lower Vertebrate ◽  
Fish Viruses ◽  
Viral Proliferation ◽  
Balance Mechanism ◽  
Insight Into ◽  
Inducible Gene

ABSTRACT Interferon (IFN) production activated by phosphorylated interferon regulatory factor 7 (IRF7) is a pivotal process during host antiviral infection. For viruses, suppressing the host IFN response is beneficial for viral proliferation; in such cases, evoking host-derived IFN negative regulators would be very useful for viruses. Here, we report that the zebrafish rapunzel 5 (RPZ5) protein which activated by virus degraded phosphorylated IRF7 is activated by TANK-binding kinase 1 (TBK1), leading to a reduction in IFN production. Upon viral infection, zebrafish rpz5 was significantly upregulated, as was ifn, in response to the stimulation. Overexpression of RPZ5 blunted the IFN expression induced by both viral and retinoic acid-inducible gene I (RIG-I) like-receptor (RLR) factors. Subsequently, RPZ5 interacted with RLRs but did not affect the stabilization of the proteins in the normal state. Interestingly, RPZ5 degraded the phosphorylated IRF7 under TBK1 activation through K48-linked ubiquitination. Finally, the overexpression of RPZ5 remarkably reduced the host cell antiviral capacity. These findings suggest that zebrafish RPZ5 is a negative regulator of phosphorylated IRF7 and attenuates IFN expression during viral infection, providing insight into the IFN balance mechanism in fish. IMPORTANCE The phosphorylation of IRF7 is helpful for host IFN production to defend against viral infection; thus, it is a potential target for viruses to mitigate the antiviral response. We report that the fish RPZ5 is an IFN negative regulator induced by fish viruses and degrades the phosphorylated IRF7 activated by TBK1, leading to IFN suppression and promotion of viral proliferation. These findings reveal a novel mechanism for interactions between the host cell and viruses in the lower vertebrate.

scholarly journals Modelling Degradation and Replication Kinetics of the Zika Virus In Vitro Infection

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 547
Author(s):  
Veronika Bernhauerová ◽  
Veronica V. Rezelj ◽  
Marco Vignuzzi
Keyword(s):  
Mathematical Model ◽  
Viral Infection ◽  
Host Cell ◽  
Decay Time ◽  
Zika Virus ◽  
Infectious Virus ◽  
Numerical Characterization ◽  
The Mathematical Model

Mathematical models of in vitro viral kinetics help us understand and quantify the main determinants underlying the virus–host cell interactions. We aimed to provide a numerical characterization of the Zika virus (ZIKV) in vitro infection kinetics, an arthropod-borne emerging virus that has gained public recognition due to its association with microcephaly in newborns. The mathematical model of in vitro viral infection typically assumes that degradation of extracellular infectious virus proceeds in an exponential manner, that is, each viral particle has the same probability of losing infectivity at any given time. We incubated ZIKV stock in the cell culture media and sampled with high frequency for quantification over the course of 96 h. The data showed a delay in the virus degradation in the first 24 h followed by a decline, which could not be captured by the model with exponentially distributed decay time of infectious virus. Thus, we proposed a model, in which inactivation of infectious ZIKV is gamma distributed and fit the model to the temporal measurements of infectious virus remaining in the media. The model was able to reproduce the data well and yielded the decay time of infectious ZIKV to be 40 h. We studied the in vitro ZIKV infection kinetics by conducting cell infection at two distinct multiplicity of infection and measuring viral loads over time. We fit the mathematical model of in vitro viral infection with gamma distributed degradation time of infectious virus to the viral growth data and identified the timespans and rates involved within the ZIKV-host cell interplay. Our mathematical analysis combined with the data provides a well-described example of non-exponential viral decay dynamics and presents numerical characterization of in vitro infection with ZIKV.

scholarly journals USP1–UAF1 deubiquitinase complex stabilizes TBK1 and enhances antiviral responses

2017 ◽  
Vol 214 (12) ◽  
pp. 3553-3563 ◽  
Author(s):  
Zhongxia Yu ◽  
Hui Song ◽  
Mutian Jia ◽  
Jintao Zhang ◽  
Wenwen Wang ◽  
...  
Keyword(s):  
Viral Infection ◽  
Degradation Process ◽  
Viral Diseases ◽  
Immune Homeostasis ◽  
Regulatory Factor ◽  
Antiviral Responses ◽  
Innate Antiviral Immunity ◽  
Irf3 Activation

Optimal activation of TANK-binding kinase 1 (TBK1) is crucial for initiation of innate antiviral immunity and maintenance of immune homeostasis. Although several E3 ubiquitin ligases have been reported to regulate TBK1 activation by mediating its polyubiquitination, the functions of deubiquitinase on TBK1 activity remain largely unclear. Here, we identified a deubiquitinase complex, which is formed by ubiquitin specific peptidase 1 (USP1) and USP1-associated factor 1 (UAF1), as a viral infection–induced physiological enhancer of TBK1 expression. USP1–UAF1 complex enhanced TLR3/4 and RIG-I–induced IFN regulatory factor 3 (IRF3) activation and subsequent IFN-β secretion. Mechanistically, USP1 and UAF1 bound to TBK1, removed its K48-linked polyubiquitination, and then reversed the degradation process of TBK1. Furthermore, we found that ML323, a specific USP1–UAF1 inhibitor, attenuated IFN-β expression and enhanced viral replication both in vitro and in vivo. Therefore, our results outline a novel mechanism for the control of TBK1 activity and suggest USP1–UAF1 complex as a potential target for the prevention of viral diseases.

Market Influence Analytics in a Digital Ecosystem

2012 ◽  
Vol 2 (4) ◽  
pp. 42-53 ◽  
Author(s):  
Vandana Ahuja
Keyword(s):  
Negative Impact ◽  
Information Age ◽  
Product Positioning ◽  
Careful Evaluation ◽  
Digital Ecosystem ◽  
New Business ◽  
Marketing Intelligence ◽  
Micro Level ◽  
Viral Proliferation ◽  
Insight Into

The internet provides opportunities for marketing which extend from the micro level of electronic contacts to the macro level of new business opportunities. As the democratisation of consumer expression leads to a viral proliferation of information online, the new age communication ecosystem has prompted the need for a careful evaluation of the potential of what is being called Consumer Generated internet content, creating new challenges for Marketing Intelligence. These offerings of the Information age have garnered adequate potential to engineer business transformations. Consumer Generated Media (CGM) comprises the content generated by consumers within online venues such as Internet forums, Blogs, Wikis, discussion lists, etc. Leveraging CGM and channelizing it appropriately has become critical for organisations for understanding and managing market performance, product positioning, and driving brand reputations. The biggest challenge in front of organizations now is to harvest CGM to help marketers gain insight into the online market conversations taking place. Efforts are on by marketing in organizations to track the volume, origin, flow, and trajectory of the conversations in real time as they evolve, study the domain of Individual Internet Worth and map the scope, reach and influence of the same on topics that might have a positive or negative impact on a company’s products, promotions, and reputation.

scholarly journals Efficacy of Garlic and Onion against virus

2019 ◽  
Vol 10 (4) ◽  
pp. 3578-3586 ◽  
Author(s):  
Neha Sharma
Keyword(s):  
Viral Infection ◽  
Host Cell ◽  
Antiviral Effect ◽  
Viral Assembly ◽  
Organosulfur Compounds ◽  
Phospholipid Membrane ◽  
Safe Alternative ◽  
Virus Attachment ◽  
Current Scenario ◽  
Pass Through

In the current scenario, pharmaceutical industry is dependent on chemical based drugs to treat viral infection. However, these drugs are known to induce many side effects in human body. There is pressing need to promote safe alternative to chemical based antiviral drugs. Onion and garlic are natural sources which are known to possess antiviral properties. It is well known that onion and garlic are rich source of organosulfur compounds. Organosulfur compounds like quercetin and allicin are associated with inhibition of viral infection. These chemicals can hinder virus attachment to host cell, alter transcription and translation of viral genome in host cell and also affect viral assembly. Quercetin can affect entry and attachment of Enterovirus and Influenza virus on host cell. This compound also has ability to inhibit RNA polymerase which is necessary for viral replication. Quercetin also inhibit process by which virus alter signalling pathway in host cell. Organosulfur compounds like allicin, diallyl trisulfide and ajoene are main chemicals which impart antiviral property to garlic. It is known that allicin can pass through phospholipid membrane of cell and can further contribute in inhibiting viral multiplication. Considering numerous studies which corroborate antiviral effect of onion and garlic, this paper recommends consumption of these plants as a safe alternative to prevent virus infection.

scholarly journals Tumor Necrosis Factor-α-Induced Protein 8-Like 2 Negatively Regulates Innate Immunity Against RNA Virus by Targeting RIG-I in Macrophages

2021 ◽  
Vol 12 ◽  
Author(s):  
Ziqi Zou ◽  
Mengyao Li ◽  
Yunlian Zhou ◽  
Jiaying Li ◽  
Ting Pan ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Retinoic Acid ◽  
Viral Infection ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Rna Virus ◽  
Type I ◽  
Factor Α ◽  
Necrosis Factor ◽  
Inducible Gene

A systematic and flexible immunoregulatory network is required to ensure the proper outcome of antiviral immune signaling and maintain homeostasis during viral infection. Tumor necrosis factor-α-induced protein 8-like 2 (TIPE2), a novel immunoregulatory protein, has been extensively studied in inflammatory response, apoptosis, and cancer. However, the function of TIPE2 in antiviral innate immunity is poorly clarified. In this study, we reported that the expression of TIPE2 declined at the early period and then climbed up in macrophages under RNA virus stimulation. Knockout of TIPE2 in the macrophages enhanced the antiviral capacity and facilitated type I interferon (IFN) signaling after RNA viral infection both in vitro and in vivo. Consistently, overexpression of TIPE2 inhibited the production of type I IFNs and pro-inflammatory cytokines, and thus promoted the viral infection. Moreover, TIPE2 restrained the activation of TBK1 and IRF3 in the retinoic acid inducible gene-I (RIG-I)-like receptors (RLR) signaling pathway by directly interacting with retinoic acid inducible gene-I (RIG-I). Taken together, our results suggested that TIPE2 suppresses the type I IFN response induced by RNA virus by targeting RIG-I and blocking the activation of downstream signaling. These findings will provide new insights to reveal the immunological function of TIPE2 and may help to develop new strategies for the clinical treatment of RNA viral infections.

scholarly journals Ataxia Telangiectasia Mutated Kinase Mediates NF-κB Serine 276 Phosphorylation and Interferon Expression via the IRF7-RIG-I Amplification Loop in Paramyxovirus Infection

2014 ◽  
Vol 89 (5) ◽  
pp. 2628-2642 ◽  
Author(s):  
Ling Fang ◽  
Sanjeev Choudhary ◽  
Bing Tian ◽  
Istvan Boldogh ◽  
Chunying Yang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Retinoic Acid ◽  
Dna Damage Response ◽  
Type I ◽  
Regulatory Factor ◽  
Ataxia Telangiectasia Mutated ◽  
Damage Response ◽  
Amplification Loop ◽  
Inducible Gene

ABSTRACTRespiratory syncytial virus (RSV) is a primary etiological agent of childhood lower respiratory tract disease. Molecular patterns induced by active infection trigger a coordinated retinoic acid-inducible gene I (RIG-I)-Toll-like receptor (TLR) signaling response to induce inflammatory cytokines and antiviral mucosal interferons. Recently, we discovered a nuclear oxidative stress-sensitive pathway mediated by the DNA damage response protein, ataxia telangiectasia mutated (ATM), in cytokine-induced NF-κB/RelA Ser 276 phosphorylation. Here we observe that ATM silencing results in enhanced single-strand RNA (ssRNA) replication of RSVand Sendai virus, due to decreased expression and secretion of type I and III interferons (IFNs), despite maintenance of IFN regulatory factor 3 (IRF3)-dependent IFN-stimulated genes (ISGs). In addition to enhanced oxidative stress, RSV replication enhances foci of phosphorylated histone 2AX variant (γH2AX), Ser 1981 phosphorylation of ATM, and IKKγ/NEMO-dependent ATM nuclear export, indicating activation of the DNA damage response. ATM-deficient cells show defective RSV-induced mitogen and stress-activated kinase 1 (MSK-1) Ser 376 phosphorylation and reduced RelA Ser 276 phosphorylation, whose formation is required for IRF7 expression. We observe that RelA inducibly binds the native IFN regulatory factor 7 (IRF7) promoter in an ATM-dependent manner, and IRF7 inducibly binds to the endogenous retinoic acid-inducible gene I (RIG-I) promoter. Ectopic IRF7 expression restores RIG-I expression and type I/III IFN expression in ATM-silenced cells. We conclude that paramyxoviruses trigger the DNA damage response, a pathway required for MSK1 activation of phospho Ser 276 RelA formation to trigger the IRF7-RIG-I amplification loop necessary for mucosal IFN production. These data provide the molecular pathogenesis for defects in the cellular innate immunity of patients with homozygous ATM mutations.IMPORTANCERNA virus infections trigger cellular response pathways to limit spread to adjacent tissues. This “innate immune response” is mediated by germ line-encoded pattern recognition receptors that trigger activation of two, largely independent, intracellular NF-κB and IRF3 transcription factors. Downstream, expression of protective antiviral interferons is amplified by positive-feedback loops mediated by inducible interferon regulatory factors (IRFs) and retinoic acid inducible gene (RIG-I). Our results indicate that a nuclear oxidative stress- and DNA damage-sensing factor, ATM, is required to mediate a cross talk pathway between NF-κB and IRF7 through mediating phosphorylation of NF-κB. Our studies provide further information about the defects in cellular and innate immunity in patients with inherited ATM mutations.

scholarly journals Tripartite Motif-Containing Protein 28 Is a Small Ubiquitin-Related Modifier E3 Ligase and Negative Regulator of IFN Regulatory Factor 7

2011 ◽  
Vol 187 (9) ◽  
pp. 4754-4763 ◽  
Author(s):  
Qiming Liang ◽  
Hongying Deng ◽  
Xiaojuan Li ◽  
Xianfang Wu ◽  
Qiyi Tang ◽  
...  
Keyword(s):  
E3 Ligase ◽  
Negative Regulator ◽  
Regulatory Factor ◽  
Tripartite Motif

scholarly journals Global Transcriptional Responses of Pseudomonas aeruginosa to Phage PRR1 Infection

2007 ◽  
Vol 82 (5) ◽  
pp. 2324-2329 ◽  
Author(s):  
Janne J. Ravantti ◽  
Tanja M. Ruokoranta ◽  
A. Marika Alapuranen ◽  
Dennis H. Bamford
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Viral Infection ◽  
Host Cell ◽  
Cell Function ◽  
Growth Conditions ◽  
Growth Cycle ◽  
Global Changes ◽  
Mrna Levels ◽  
Transcriptional Responses ◽  
Number Of Genes

ABSTRACT The infectious cycles of viruses are known to cause dramatic changes to host cell function. The development of microarray technology has provided means to monitor host cell responses to viral infection at the level of global changes in mRNA levels. We have applied this methodology to investigate gene expression changes caused by a small, icosahedral, single-stranded-RNA phage, PRR1 (a member of the Leviviridae family), on its host, Pseudomonas aeruginosa, at different times during its growth cycle. Viral infection in this system resulted in changes in expression levels of <4% of P. aeruginosa genes. Interestingly, the number of genes affected by viral infection was significantly lower than the number of genes affected by changes in growth conditions during the experiment. Compared with a similar study that focused on the complex, double-stranded-DNA bacterial virus PRD1, it was evident that there were no universal responses to viral infection. However, in both cases, translation was affected in infected cells.

Ayurvedic system a new possible safe and effective way to get rid of this critical nCOVID-19 pandemic situation- A review

2021 ◽  
Vol 07 ◽  
Author(s):  
Sumel Ashique ◽  
Navjot K Sandhu
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Viral Infection ◽  
Traditional Medicine ◽  
Host Cell ◽  
Western Medicine ◽  
Treatment Strategies ◽  
Unani Medicine ◽  
System A ◽  
The World

: The nCOVID-19 virus has become the most threatening infections disease all over the world. From the beginning till today a large number of researches is going on to develop appropriate therapeutics that can prevent and cure this viral infection successfully. But unfortunately, modern western medicine could not find any effective drug having no toxic effects on host cell. TCM (traditional Chinese Medicine) has shown promising effect against nCOVID-19. This TCM contains natural occurring herbal decoctions which showed promising blocking of viral progression in host cell. These ayurvedic formulations containing homeopathic medicine, unani medicine and yoga to challenge the virus. The traditional medicine system is unable to cure properly but it can be a possible preventing strategy to stop this virus pandemicity. This review focuses how the ayurvedic medicines, homeopathic treatment strategies and yoga can impact to prevent the viral infection.

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