scholarly journals A RIG-I 2CARD-MAVS200 Chimeric Protein Reconstitutes IFN-β Induction and Antiviral Response in Models Deficient in Type I IFN Response

2015 ◽  
Vol 7 (5) ◽  
pp. 466-481 ◽  
Author(s):  
Estanislao Nistal-Villán ◽  
Estefanía Rodríguez-García ◽  
Marianna Di Scala ◽  
Roberto Ferrero-Laborda ◽  
Cristina Olagüe ◽  
...  
Keyword(s):  
Viral Infections ◽  
Chimeric Protein ◽  
Signaling Cascade ◽  
Type I ◽  
Type I Ifn ◽  
Delivery Vehicle ◽  
Adeno Associated Virus ◽  
Antiviral State ◽  
Chimeric Construct ◽  
Sensor Proteins

RIG-I-like receptors (RLRs) are cellular sensor proteins that detect certain RNA species produced during viral infections. RLRs activate a signaling cascade that results in the production of IFN-β as well as several other cytokines with antiviral and proinflammatory activities. We explored the potential of different constructs based on RLRs to induce the IFN-β pathway and create an antiviral state in type I IFN-unresponsive models. A chimeric construct composed of RIG-I 2CARD and the first 200 amino acids of MAVS (2CARD-MAVS200) showed an enhanced ability to induce IFN-β when compared to other stimulatory constructs. Furthermore, this human chimeric construct showed a superior ability to activate IFN-β expression in cells from various species. This construct was found to overcome the restrictions of blocking IFN-β induction or signaling by a number of viral IFN-antagonist proteins. Additionally, the antiviral activity of this chimera was demonstrated in influenza virus and HBV infection mouse models using adeno-associated virus (AAV) vectors as a delivery vehicle. We propose that AAV vectors expressing 2CARD-MAVS200 chimeric protein can reconstitute IFN-β induction and recover a partial antiviral state in different models that do not respond to recombinant IFN-β treatment.

Biologics targeting type I interferons in SLE: A meta-analysis and systematic review of randomised controlled trials

Lupus ◽  
2020 ◽  
Vol 29 (14) ◽  
pp. 1845-1853
Author(s):  
Jeffery Wei Heng Koh ◽  
Cheng Han Ng ◽  
Sen Hee Tay
Keyword(s):  
Systematic Review ◽  
Herpes Zoster ◽  
Lupus Erythematosus ◽  
Viral Infections ◽  
Meta Analysis ◽  
Type I Interferons ◽  
Type I ◽  
Upper Respiratory Tract ◽  
Type I Ifn ◽  
Tract Infections

Objective The feed-forward loop of type I interferons (IFNs) production and subsequent immunopathology of systemic lupus erythematosus (SLE) has been hypothesised to be disrupted with inhibition of IFNα or type I IFN receptor subunit 1 (IFNAR). This systematic review and meta-analysis present the treatment efficacy and safety profile of monoclonal antibodies inhibiting IFNα or IFNAR. Methods A search was done using Medline, Embase and ClinicalTrials.gov for biologics targeting IFNα or IFNAR in SLE up to 3 Jan 2020. For the meta-analysis, analyses of binary variables were pooled using odds ratio (OR) with the Mantel Haenszel model. Results Anifrolumab 300 mg (n = 3 studies, 927 patients) was more effective than placebo in achieving SRI(4) (pooled OR = 1.91, CI 1.11-3.28, P = 0.02) and BICLA response (pooled OR = 2.25, CI 1.72-2.95, P < 0.00001). In SLE patients with high type I IFN gene signature, SRI(4) response was not achieved with anifrolumab in 2 studies, 450 patients. Treatment with IFNα and IFNAR inhibitors (n = 7 studies, 1590 patients) increased the risk of herpes zoster infection (pooled OR = 3.72, CI 1.88–7.39, P = 0.0002), upper respiratory tract infections, nasopharyngitis and bronchitis. Conclusion This meta-analysis substantiates IFNAR as a therapeutic target in SLE. Inhibition of type I IFNs predisposes to herpes zoster and other viral infections.

scholarly journals HIV blocks Type I IFN signaling through disruption of STAT1 phosphorylation

2018 ◽  
Vol 24 (8) ◽  
pp. 490-500 ◽  
Author(s):  
Nam V Nguyen ◽  
James T Tran ◽  
David Jesse Sanchez
Keyword(s):  
Gene Expression ◽  
Adaptor Protein ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Antiviral State ◽  
Receptor Signaling Pathway ◽  
Multiple Signaling ◽  
Inducible Gene ◽  
Stat Pathway

This study investigates the modulation of Type I IFN induction of an antiviral state by HIV. IFNs, including IFN-α, are key innate immune cytokines that activate the JAK/STAT pathway leading to the expression of IFN-stimulated genes. IFN-stimulated gene expression establishes the antiviral state, limiting viral infection in IFN-α-stimulated microenvironments. Our previous studies have shown that HIV proteins disrupt the induction of IFN-α by degradation of IFN-β promoter stimulator-1, an adaptor protein for the up-regulation and release of IFN-α into the local microenvironment via the retinoic acid-inducible gene 1-like receptor signaling pathway. However, IFN-α is still released from other sources such as plasmacytoid dendritic cells via TLR-dependent recognition of HIV. Here we report that the activation of the JAK/STAT pathway by IFN-α stimulation is disrupted by HIV proteins Vpu and Nef, which both reduce IFN-α induction of STAT1 phosphorylation. Thus, HIV would still be able to avoid antiviral protection induced by IFN-α in the local microenvironment. These findings show that HIV blocks multiple signaling points that would lead to the up-regulation of IFN-stimulated genes, allowing more effective replication in IFN-α-rich environments.

scholarly journals Type I IFN Substitutes for T Cell Help during Viral Infections

2010 ◽  
Vol 186 (2) ◽  
pp. 754-763 ◽  
Author(s):  
Melanie Wiesel ◽  
Wolfgang Kratky ◽  
Annette Oxenius
Keyword(s):  
T Cell ◽  
Viral Infections ◽  
Type I ◽  
Type I Ifn ◽  
T Cell Help

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 Role of the transcriptional regulator SP140 in resistance to bacterial infections via repression of type I interferons

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Daisy X Ji ◽  
Kristen C Witt ◽  
Dmitri I Kotov ◽  
Shally R Margolis ◽  
Alexander Louie ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Negative Regulator ◽  
Type I Interferons ◽  
Type I ◽  
Type I Ifn ◽  
Viral Immunity ◽  
Type I Ifns ◽  
Important Negative Regulator

Type I interferons (IFNs) are essential for anti-viral immunity, but often impair protective immune responses during bacterial infections. An important question is how type I IFNs are strongly induced during viral infections, and yet are appropriately restrained during bacterial infections. The Super susceptibility to tuberculosis 1 (Sst1) locus in mice confers resistance to diverse bacterial infections. Here we provide evidence that Sp140 is a gene encoded within the Sst1 locus that represses type I IFN transcription during bacterial infections. We generated Sp140-/- mice and find they are susceptible to infection by Legionella pneumophila and Mycobacterium tuberculosis. Susceptibility of Sp140-/- mice to bacterial infection was rescued by crosses to mice lacking the type I IFN receptor (Ifnar-/-). Our results implicate Sp140 as an important negative regulator of type I IFNs that is essential for resistance to bacterial infections.

scholarly journals IFN-β signalling regulates RAW 264.7 macrophage activation, cytokine production, and killing activity

2019 ◽  
Vol 26 (3) ◽  
pp. 172-182
Author(s):  
Yalda Karimi ◽  
Elizabeth C Giles ◽  
Fatemeh Vahedi ◽  
Marianne V Chew ◽  
Tina Nham ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Critical Role ◽  
Raw 264.7 ◽  
Type I ◽  
Type I Ifn ◽  
Killing Activity ◽  
Raw 264.7 Macrophage

Type I IFN holds a critical role in host defence, providing protection against pathogenic organisms through coordinating a pro-inflammatory response. Type I IFN provides additional protection through mitigating this inflammatory response, preventing immunopathology. Within the context of viral infections, type I IFN signalling commonly results in successful viral clearance. Conversely, during bacterial infections, the role of type I IFN is less predictable, leading to either detrimental or beneficial outcomes. The factors responsible for the variability in the role of type I IFN remain unclear. Here, we aimed to elucidate differences in the effect of type I IFN signalling on macrophage functioning in the context of TLR activation. Using RAW 264.7 macrophages, we observed the influence of type I IFN to be dependent on the type of TLR ligand, length of TLR exposure and the timing of IFN-β signalling. However, in all conditions, IFN-β increased the production of the anti-inflammatory cytokine IL-10. Examination of RAW 264.7 macrophage function showed type I IFN to induce an activated phenotype by up-regulating MHC II expression and enhancing killing activity. Our results support a context-dependent role for type I IFN in regulating RAW 264.7 macrophage activity.

Retinoic Acid Inducible Gene-I like Receptors Activate Snail to Limit RNA Viral Infections

2021 ◽  
Author(s):  
Dhiviya Vedagiri ◽  
Divya Gupta ◽  
Anurag Mishra ◽  
Gayathri Krishna ◽  
Meenakshi Bhaskar ◽  
...  
Keyword(s):  
Viral Infections ◽  
Epithelial Mesenchymal Transition ◽  
Ectopic Expression ◽  
Antiviral Response ◽  
Poly I:C ◽  
Type I ◽  
Type I Ifn ◽  
Mesenchymal Transition ◽  
Type I Ifns ◽  
General Response

RLRs are important cytosolic PRRs that sense viral RNA before mounting a response leading to the activation of Type-I IFNs. Several viral infections induce epithelial-mesenchymal transition (EMT), even as its significance remains unclear. Here, we describe that EMT or EMT like process is a general response to viral infections. Our studies identify a previously unknown mechanism of regulation of an important EMT-TF Snail during RNA viral infections, and describe its possible implication. RNA viral infections, poly (I:C) transfection, and ectopic expression of RLR components induced Snail levels, indicating that RLR pathway could regulate its expression. Detailed examination using MAVS-KO cells established that MAVS is essential in this regulation. We identified two ISREs in SNAI1 promoter region and demonstrated that they are important in its transcriptional activation by phosphorylated IRF3. Increasing the levels of Snail activated RLR pathway and dramatically limited replication of RNA viruses DENV, JEV and VSV, pointing to their antiviral functions. Knock-down of Snail resulted in considerable increase in JEV titer, validating its antiviral functions. Finally, TGF-β mediated IFNB activation was dependent on Snail levels, confirming its important role in Type-I IFN activation. Thus, EMT-TF Snail is transcriptionally co-regulated with Type-I IFN by RLRs and in turn promotes RLR pathway, further strengthening the antiviral state in the cell. Our work identified an interesting mechanism of regulation of Snail that demonstrates potential co-regulation of multiple innate antiviral pathways triggered by RLRs. Identification of antiviral functions of Snail also provides an opportunity to expand the sphere of RLR signaling. IMPORTANCE RLRs sense viral genomic RNA or the dsRNA intermediates and trigger the activation of Type I IFNs. Snail transcription factor, commonly associated with epithelial-mesenchymal transition, has been reported to facilitate EMT in several viral infections. Much of these reports come from oncoviruses, leading to the speculation that EMT induced during infection is an important factor in the oncogenesis triggered by these infections. However, our studies reveal that EMT or EMT like processes during viral infections have important functions in antiviral response. We have characterized a new mechanism of transcriptional regulation of Snail by IRF3 through ISRE in their promoters and this finding could have importance in non-viral contexts as well. We also identify that EMT-TF Snail promotes antiviral status of the infected cells through RLR pathway. This work characterizes a new regulatory mechanism of activation of Snail and establishes its unidentified function in antiviral response.

scholarly journals Identification of poly(ADP-ribose) polymerase 9 (PARP9) as a noncanonical sensor for RNA virus in dendritic cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Junji Xing ◽  
Ao Zhang ◽  
Yong Du ◽  
Mingli Fang ◽  
Laurie J. Minze ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Protective Immunity ◽  
Viral Infections ◽  
Rna Virus ◽  
Critical Role ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Mitochondrial Antiviral Signaling ◽  
Phosphoinositide 3 Kinase

AbstractInnate immune cells are critical in protective immunity against viral infections, involved in sensing foreign viral nucleic acids. Here we report that the poly(ADP-ribose) polymerase 9 (PARP9), a member of PARP family, serves as a non-canonical sensor for RNA virus to initiate and amplify type I interferon (IFN) production. We find knockdown or deletion of PARP9 in human or mouse dendritic cells and macrophages inhibits type I IFN production in response to double strand RNA stimulation or RNA virus infection. Furthermore, mice deficient for PARP9 show enhanced susceptibility to infections with RNA viruses because of the impaired type I IFN production. Mechanistically, we show that PARP9 recognizes and binds viral RNA, with resultant recruitment and activation of the phosphoinositide 3-kinase (PI3K) and AKT3 pathway, independent of mitochondrial antiviral-signaling (MAVS). PI3K/AKT3 then activates the IRF3 and IRF7 by phosphorylating IRF3 at Ser385 and IRF7 at Ser437/438 mediating type I IFN production. Together, we reveal a critical role for PARP9 as a non-canonical RNA sensor that depends on the PI3K/AKT3 pathway to produce type I IFN. These findings may have important clinical implications in controlling viral infections and viral-induced diseases by targeting PARP9.

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