scholarly journals Suppression of Type I Interferon Signaling by E1A via RuvBL1/Pontin

2017 ◽  
Vol 91 (8) ◽  
Author(s):  
Oladunni Olanubi ◽  
Jasmine Rae Frost ◽  
Sandi Radko ◽  
Peter Pelka
Keyword(s):  
Gene Expression ◽  
Cellular Response ◽  
Type I Interferon ◽  
Early Gene ◽  
Interferon Response ◽  
Type I ◽  
Dependent Manner ◽  
Interferon Signaling ◽  
Interferon Pathway ◽  
Regulated Promoters

ABSTRACT Suppression of interferon signaling is of paramount importance to a virus. Interferon signaling significantly reduces or halts the ability of a virus to replicate; therefore, viruses have evolved sophisticated mechanisms that suppress activation of the interferon pathway or responsiveness of the infected cell to interferon. Adenovirus has multiple modes of inhibiting the cellular response to interferon. Here, we report that E1A, previously shown to regulate interferon signaling in multiple ways, inhibits interferon-stimulated gene expression by modulating RuvBL1 function. RuvBL1 was previously shown to affect type I interferon signaling. E1A binds to RuvBL1 and is recruited to RuvBL1-regulated promoters in an interferon-dependent manner, preventing their activation. Depletion of RuvBL1 impairs adenovirus growth but does not appear to significantly affect viral protein expression. Although RuvBL1 has been shown to play a role in cell growth, its depletion had no effect on the ability of the virus to replicate its genome or to drive cells into S phase. E1A was found to bind to RuvBL1 via the C terminus of E1A, and this interaction was important for suppression of interferon-stimulated gene transcriptional activation and recruitment of E1A to interferon-regulated promoters. Here, we report the identification of RuvBL1 as a new target for adenovirus in its quest to suppress the interferon response. IMPORTANCE For most viruses, suppression of the interferon signaling pathway is crucial to ensure a successful replicative cycle. Human adenovirus has evolved several different mechanisms that prevent activation of interferon or the ability of the cell to respond to interferon. The viral immediate-early gene E1A was previously shown to affect interferon signaling in several different ways. Here, we report a novel mechanism reliant on RuvBL1 that E1A uses to prevent activation of interferon-stimulated gene expression following infection or interferon treatment. This adds to the growing knowledge of how viruses are able to inhibit interferon and identifies a novel target used by adenovirus for modulation of the cellular interferon pathway.

scholarly journals Impact of Intermediate Hyperglycemia and Diabetes on Immune Dysfunction in Tuberculosis

2020 ◽  
Author(s):  
Clare Eckold ◽  
Vinod Kumar ◽  
January Weiner ◽  
Bachti Alisjahbana ◽  
Anca-Lelia Riza ◽  
...  
Keyword(s):  
Gene Expression ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Expression Change ◽  
Tb Treatment ◽  
Increased Risk ◽  
Patients With Diabetes ◽  
Transcriptomic Signature ◽  
Interferon Responses

Abstract Background People with diabetes have an increased risk of developing active tuberculosis (TB) and are more likely to have poor TB-treatment outcomes, which may impact on control of TB as the prevalence of diabetes is increasing worldwide. Blood transcriptomes are altered in patients with active TB relative to healthy individuals. The effects of diabetes and intermediate hyperglycemia (IH) on this transcriptomic signature were investigated to enhance understanding of immunological susceptibility in diabetes-TB comorbidity. Methods Whole blood samples were collected from active TB patients with diabetes (glycated hemoglobin [HbA1c] ≥6.5%) or IH (HbA1c = 5.7% to <6.5%), TB-only patients, and healthy controls in 4 countries: South Africa, Romania, Indonesia, and Peru. Differential blood gene expression was determined by RNA-seq (n = 249). Results Diabetes increased the magnitude of gene expression change in the host transcriptome in TB, notably showing an increase in genes associated with innate inflammatory and decrease in adaptive immune responses. Strikingly, patients with IH and TB exhibited blood transcriptomes much more similar to patients with diabetes-TB than to patients with only TB. Both diabetes-TB and IH-TB patients had a decreased type I interferon response relative to TB-only patients. Conclusions Comorbidity in individuals with both TB and diabetes is associated with altered transcriptomes, with an expected enhanced inflammation in the presence of both conditions, but also reduced type I interferon responses in comorbid patients, suggesting an unexpected uncoupling of the TB transcriptome phenotype. These immunological dysfunctions are also present in individuals with IH, showing that altered immunity to TB may also be present in this group. The TB disease outcomes in individuals with IH diagnosed with TB should be investigated further.

scholarly journals Role of NLRs in the Regulation of Type I Interferon Signaling, Host Defense and Tolerance to Inflammation

2021 ◽  
Vol 22 (3) ◽  
pp. 1301
Author(s):  
Ioannis Kienes ◽  
Tanja Weidl ◽  
Nora Mirza ◽  
Mathias Chamaillard ◽  
Thomas A. Kufer
Keyword(s):  
Viral Infections ◽  
Type I Interferon ◽  
Tissue Injury ◽  
Interferon Response ◽  
Type I ◽  
Interferon Signaling ◽  
Microbial Products ◽  
Interferon Responses

Type I interferon signaling contributes to the development of innate and adaptive immune responses to either viruses, fungi, or bacteria. However, amplitude and timing of the interferon response is of utmost importance for preventing an underwhelming outcome, or tissue damage. While several pathogens evolved strategies for disturbing the quality of interferon signaling, there is growing evidence that this pathway can be regulated by several members of the Nod-like receptor (NLR) family, although the precise mechanism for most of these remains elusive. NLRs consist of a family of about 20 proteins in mammals, which are capable of sensing microbial products as well as endogenous signals related to tissue injury. Here we provide an overview of our current understanding of the function of those NLRs in type I interferon responses with a focus on viral infections. We discuss how NLR-mediated type I interferon regulation can influence the development of auto-immunity and the immune response to infection.

scholarly journals SARS-CoV-2-Encoded MiRNAs Inhibit Host Type I Interferon Pathway and Mediate Allelic Differential Expression of Susceptible Gene

2021 ◽  
Vol 12 ◽  
Author(s):  
Youwei Zhu ◽  
Zhaoyang Zhang ◽  
Jia Song ◽  
Weizhou Qian ◽  
Xiangqian Gu ◽  
...  
Keyword(s):  
Differential Expression ◽  
Molecular Mechanisms ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Health Crisis ◽  
Host Interactions ◽  
Interferon Pathway ◽  
Host Innate Immune Response ◽  
Susceptible Gene

Infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing the rapid spread of coronavirus disease 2019 (COVID-19), has generated a public health crisis worldwide. The molecular mechanisms of SARS-CoV-2 infection and virus–host interactions are still unclear. In this study, we identified four unique microRNA-like small RNAs encoded by SARS-CoV-2. SCV2-miR-ORF1ab-1-3p and SCV2-miR-ORF1ab-2-5p play an important role in evasion of type I interferon response through targeting several genes in type I interferon signaling pathway. Particularly worth mentioning is that highly expressed SCV2-miR-ORF1ab-2-5p inhibits some key genes in the host innate immune response, such as IRF7, IRF9, STAT2, OAS1, and OAS2. SCV2-miR-ORF1ab-2-5p has also been found to mediate allelic differential expression of COVID-19-susceptible gene OAS1. In conclusion, these results suggest that SARS-CoV-2 uses its miRNAs to evade the type I interferon response and links the functional viral sequence to the susceptible genetic background of the host.

scholarly journals Bud13 Promotes a Type I Interferon Response by Countering Intron Retention in Irf7

2018 ◽  
Author(s):  
Luke S. Frankiw ◽  
Devdoot Majumdar ◽  
Christian Burns ◽  
Annie Moradian ◽  
Michael J. Sweredoski ◽  
...  
Keyword(s):  
Rna Binding ◽  
Type I Interferon ◽  
Intron Retention ◽  
Global Analysis ◽  
Interferon Response ◽  
Type I ◽  
Dependent Manner ◽  
Protein Levels ◽  
Expression Of Genes ◽  
Gene Expression Control

SUMMARYIntron retention (IR) has emerged as an important mechanism of gene expression control. Despite this, the factors that control IR events remain poorly understood. We observed consistent IR in one intron of the Irf7 gene and identified Bud13 as an RNA-binding protein that acts at this intron to increase the amount of successful splicing. Deficiency in Bud13 led to increased IR, decreased mature Irf7 transcript and protein levels, and consequently to a dampened type I interferon response. This impairment of Irf7 production in Bud13-deficient cells compromised their ability to withstand VSV infection. Global analysis of Bud13 knockdown and BUD13 cross-linking to RNA revealed a subset of introns that share many characteristics with the one found in Irf7 and are spliced in a Bud13-dependent manner. Deficiency of Bud13 led to decreased mature transcript from genes containing such introns. Thus, by acting as an antagonist to IR, Bud13 facilitates the expression of genes at which IR occurs.

scholarly journals Activation of RIG-I-mediated antiviral signaling triggers autophagy through the MAVS-TRAF6-Beclin-1 signaling axis

2018 ◽  
Author(s):  
Na-Rae Lee ◽  
Junsu Ban ◽  
Noh-Jin Lee ◽  
Chae-Min Yi ◽  
Jiyoon Choi ◽  
...  
Keyword(s):  
Type I Interferon ◽  
Sendai Virus ◽  
Feedback Mechanism ◽  
Innate Immune ◽  
Beclin 1 ◽  
Interferon Response ◽  
Type I ◽  
Interferon Signaling ◽  
Negative Feedback Mechanism ◽  
Signaling Axis

AbstractAutophagy has been implicated in innate immune responses against various intracellular pathogens. Recent studies have reported that autophagy can be triggered by pathogen recognizing sensors, including Toll-like receptors and cyclic guanosine monophosphate-adenosine monophosphate synthase, to participate in innate immunity. In the present study, we examined whether the RIG-I signaling pathway, which detects viral infections by recognizing viral RNA, triggers the autophagic process. The introduction of polyI:C into the cytoplasm, or Sendai virus infection, significantly induced autophagy in normal cells but not in RIG-I-deficient cells. PolyI:C transfection or Sendai virus infection induced autophagy in the cells lacking type-I interferon signaling. This demonstrated that the effect was not due to interferon signaling. RIG-I-mediated autophagy diminished by the deficiency of mitochondrial antiviral signaling protein (MAVS) or tumor necrosis factor receptor-associated factor (TRAF)6, showing that the RIG-I-MAVS-TRAF6 signaling axis was critical for RIG-I-mediated autophagy. We also found that Beclin-1 was translocated to the mitochondria, and it interacted with TRAF6 upon RIG-I activation. Furthermore, Beclin-1 underwent K63-polyubiquitination upon RIG-I activation, and the ubiquitination decreased in TRAF6-deficient cells. This suggests that the RIG-I-MAVS-TRAF6 axis induced K63-linked polyubiquitination of Beclin-1, which has been implicated in triggering autophagy. Collectively, the results of this study show that the recognition of viral infection by RIG-I is capable of inducing autophagy to control viral replication. As deficient autophagy increases the type-I interferon response, the induction of autophagy by the RIG-I pathway might also contribute to preventing an excessive interferon response as a negative-feedback mechanism.ImportanceMammalian cells utilize various innate immune sensors to detect pathogens. Among those sensors, RIG-I recognizes viral RNA to detect intracellular viral replication. Although cells experience diverse physiological changes upon viral infection, studies to understand the role of RIG-I signaling have focused on the induction of type-I interferon. Autophagy is a process that sequesters cytosolic regions and degrades the contents to maintain cellular homeostasis. Autophagy participates in the immune system, and has been known to be triggered by some innate immune sensors, such as TLR4 and cGAS. We demonstrated that autophagy can be triggered by the activation of RIG-I. In addition, we also proved that MAVS-TRAF6 downstream signaling is crucial for the process. Beclin-1, a key molecule in autophagy, is translocated to mitochondria, where it undergoes K63-ubiquitination in a TRAF6-dependent manner upon RIG-I activation. As autophagy negatively regulates RIG-I-mediated signaling, the RIG-I-mediated activation of autophagy may function as a negative-feedback mechanism.

scholarly journals Junín Virus Infection Activates the Type I Interferon Pathway in a RIG-I-Dependent Manner

2012 ◽  
Vol 6 (5) ◽  
pp. e1659 ◽  
Author(s):  
Cheng Huang ◽  
Olga A. Kolokoltsova ◽  
Nadezdha E. Yun ◽  
Alexey V. Seregin ◽  
Allison L. Poussard ◽  
...  
Keyword(s):  
Virus Infection ◽  
Type I Interferon ◽  
Type I ◽  
Dependent Manner ◽  
Junin Virus ◽  
Interferon Pathway ◽  
Junín Virus

scholarly journals Profiling transcription factor sub-networks in type I interferon signaling and in response to SARS-CoV-2 infection

2021 ◽  
Author(s):  
Chilakamarti V. Ramana
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Immune Modulation ◽  
Type I Interferon ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Interferon Signaling ◽  
Lung Epithelial

AbstractType I interferons (IFN α/β) play a central role in innate immunity to respiratory viruses, including coronaviruses. Genetic defects in type I interferon signaling were reported in a significant proportion of critically ill CoOVID-19 patients. Extensive studies on interferon-induced intracellular signal transduction pathways led to the elucidation of the Jak-Stat pathway. Furthermore, advances in gene expression profiling by microarrays have revealed that type I interferon rapidly induced multiple transcription factor mRNA levels. In this study, transcription factor profiling in the transcriptome was used to gain novel insights into the role of inducible transcription factors in response to type I interferon signaling in immune cells and in lung epithelial cells after SARS-CoV-2 infection. Modeling the interferon-inducible transcription factor mRNA data in terms of distinct sub-networks based on biological functions such as antiviral response, immune modulation, and cell growth revealed enrichment of specific transcription factors in mouse and human immune cells. The evolutionarily conserved core type I interferon gene expression consists of the inducible transcriptional factor mRNA of the antiviral response sub-network and enriched in granulocytes. Analysis of the type I interferon-inducible transcription factor sub-networks as distinct protein-protein interaction pathways revealed insights into the role of critical hubs in signaling. Interrogation of multiple microarray datasets revealed that SARS-CoV-2 induced high levels of IFN-beta and interferon-inducible transcription factor mRNA in human lung epithelial cells. Transcription factor mRNA of the three major sub-networks regulating antiviral, immune modulation, and cell growth were differentially regulated in human lung epithelial cell lines after SARS-CoV-2 infection and in the tissue samples of COVID-19 patients. A subset of type I interferon-inducible transcription factors and inflammatory mediators were specifically enriched in the lungs and neutrophils of Covid-19 patients. The emerging complex picture of type I IFN transcriptional regulation consists of a rapid transcriptional switch mediated by the Jak-Stat cascade and a graded output of the inducible transcription factor activation that enables temporal regulation of gene expression.

scholarly journals Lung epithelial cells have virus-specific and shared gene expression responses to infection by diverse respiratory viruses

2016 ◽  
Author(s):  
James T. VanLeuven ◽  
Benjamin J. Ridenhour ◽  
Craig R. Miller ◽  
Tanya A. Miura
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Influenza A ◽  
Cellular Response ◽  
Respiratory Viruses ◽  
Lung Epithelial Cells ◽  
Interferon Response ◽  
Comparative Approach ◽  
Type I ◽  
Lung Epithelial

AbstractThe severity and outcome of respiratory viral infections is partially determined by the cellular response mounted by infected lung epithelial cells. Disease prevention and treatment is dependent on our understanding of the shared and unique responses elicited by diverse viruses, yet few studies compare host responses to different viruses while controlling other experimental parameters. We compared changes in gene expression of murine lung epithelial cells infected individually by three respiratory viruses causing mild (rhinovirus, RV1B), moderate (coronavirus, MHV-1), and severe (influenza A virus, PR8) disease in mice. RV1B infection caused numerous gene expression changes, but the differential effect peaked at 12 hours post-infection. PR8 altered an intermediate number of genes whose expression continued to change through 24 hours. MHV-1 had comparatively few effects on host gene expression. The viruses elicited highly overlapping responses in antiviral genes, though MHV-1 induced a lower type I interferon response than the other two viruses. Signature genes were identified for each virus and included host defense genes for PR8, tissue remodeling genes for RV1B, and transcription factors for MHV-1. Our comparative approach identified universal and specific transcriptional signatures of virus infection that can be used to discover mechanisms of pathogenesis in the respiratory tract.

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