scholarly journals ILF3 contributes to the establishment of the antiviral type I interferon program

Author(s):  
Samir F Watson ◽  
Nicolas Bellora ◽  
Sara Macias

Abstract Upon detection of viral infections, cells activate the expression of type I interferons (IFNs) and pro-inflammatory cytokines to control viral dissemination. As part of their antiviral response, cells also trigger the translational shutoff response which prevents translation of viral mRNAs and cellular mRNAs in a non-selective manner. Intriguingly, mRNAs encoding for antiviral factors bypass this translational shutoff, suggesting the presence of additional regulatory mechanisms enabling expression of the self-defence genes. Here, we identified the dsRNA binding protein ILF3 as an essential host factor required for efficient translation of the central antiviral cytokine, IFNB1, and a subset of interferon-stimulated genes. By combining polysome profiling and next-generation sequencing, ILF3 was also found to be necessary to establish the dsRNA-induced transcriptional and translational programs. We propose a central role for the host factor ILF3 in enhancing expression of the antiviral defence mRNAs in cellular conditions where cap-dependent translation is compromised.

2019 ◽  
Author(s):  
Samir F. Watson ◽  
Nicolas Bellora ◽  
Sara Macias

AbstractUpon detection of viral infections, cells activate the expression of type I interferons (IFNs) and pro-inflammatory cytokines to control viral dissemination. As part of their antiviral response, cells also trigger the translational shutoff response which prevents translation of viral mRNAs and cellular mRNAs in a non-selective manner. Intriguingly, mRNAs encoding for antiviral factors bypass this translational shutoff, suggesting the presence of additional regulatory mechanisms enabling expression of the self-defence genes. Here, we identified the dsRNA binding protein ILF3 as an essential host factor required for efficient translation of the central antiviral cytokine, IFNB1, and a subset of interferon-stimulated genes. By combining polysome profiling and next-generation sequencing, ILF3 was also found to be necessary to establish the dsRNA-induced transcriptional and translational programs. We propose a central role for the host factor ILF3 in enhancing expression of the antiviral defence mRNAs in cellular conditions where cap-dependent translation is compromised.


2017 ◽  
Vol 64 (2) ◽  
Author(s):  
Weronika Ratajczak ◽  
Paulina Niedźwiedzka-Rystwej ◽  
Beata Tokarz-Deptuła ◽  
Wiesław Deptuła

Interferons (IFN) are pivotal regulators of immunological processes. The paper describes mainly type I interferons -α and –β and its recently recounted signaling pathways, especially ISG – interferon stimulated genes, having a crucial role in regulating IFN recruitment. Moreover, the paper shows the data on the role of interferons -α and –β in infections – not only commonly known viral infections, but also bacterial, fungal and parasitic. 


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 542.2-542
Author(s):  
A. Avdeeva ◽  
E. Tchetina ◽  
G. Markova ◽  
E. Nasonov

Background:Type I interferons (IFN-Is) are a group of molecules with pleiotropic effects on the immune system forming a crucial link between innate and adaptive immune responses. The type I interferon pathway has been implicated in the pathogenesis of a number of rheumatic diseases, including rheumatoid arthritis. IFN activity is usually quantified using expression of interferon-stimulated genes (ISGs) referred to as an IFN signature. Acellbia (BIOCAD) is the first Russian rituximab (RTX) biosimilar which was approved for medical use in rheumatoid arthritis (RA) patients in Russia and some CIS countries.Objectives:To evaluate the changes in expression of ISGs in patients (pts) with RA during RTX biosimilar therapyMethods:20 RA pts (18 woman, Me;IQR age 61.5(54-66.5) years, disease duration 39.5(20-84) months, mean DAS 28 5.6(4.9-6.8)) received two intravenous RTX biosimilar infusions (600 mg №2) in combination with DMARDs and glucocorticoids. Laboratory biomarkers were assessed at baseline and 24 weeks after the first infusion of RTX. 5 genes (IFI44L, MX1, IFIT 1, RSAD2, EPSTI1) were selected for evaluation of the “interferon signature” (Type I IFN gene signature – IFNGS). IFI44L and IFIT1 expression was undetectable, therefore the remaining three genes (MSX1, EPSTI1, RSAD2) were included into further analysis. IFNGS was calculated as the average expression values of the three selected genes. The control group included 20 age and gender matching healthy donors.Results:The baseline expression levels of MX1-11.48 (5.45-19.38), EPSTI1-12.83 (5.62-19.64), RSAD2-5.16 (2.73-10.4), and IFNGS-10.3 (5.18-17.12) in RA patients were significantly higher compared to healthy donors– 1,26 (0,73-1,6); 1,06 (0,81-1,48); 0,93 (0,72-1,19); 1,09 (0,92-1,42), (p<0.05, respectively). IFNGS was detected in 15 (75%) patients, and was not found in 5 (15%) patients. RTX induced reduction in disease activity, and the level of acute phase reactants (ESR, CRP) after 12 and 24 weeks of therapy, p<0.05 (fig.1). Increased RSAD 2 expression (p<0.05) and a trend to increasing IFNGS levels (p=0.06) were documented in the whole group, and also in patients with moderate treatment effects by week 24. Among patients with a good EULAR response to therapy, changes in expression were not significant (p> 0.05) (fig.1)Figure 1.Conclusion:Expression of IFN-stimulated genes was increased in RA patients compared to healthy donors. Increased RSAD2 and IFNGS expression was documented in patients with moderate effect of RTX therapy, therefore, these findings have important clinical relevance as predictors of RA clinical course which necessitates personified approach to treatment.Disclosure of Interests:None declared


Infection ◽  
2021 ◽  
Author(s):  
Jan-Moritz Doehn ◽  
Christoph Tabeling ◽  
Robert Biesen ◽  
Jacopo Saccomanno ◽  
Elena Madlung ◽  
...  

AbstractCoronavirus disease 2019 (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Type I interferons are important in the defense of viral infections. Recently, neutralizing IgG auto-antibodies against type I interferons were found in patients with severe COVID-19 infection. Here, we analyzed expression of CD169/SIGLEC1, a well described downstream molecule in interferon signaling, and found increased monocytic CD169/SIGLEC1 expression levels in patients with mild, acute COVID-19, compared to patients with severe disease. We recommend further clinical studies to evaluate the value of CD169/SIGLEC1 expression in patients with COVID-19 with or without auto-antibodies against type I interferons.


2021 ◽  
Author(s):  
Lauren A. Todd ◽  
Maxwell P. Bui-Marinos ◽  
Barbara A. Katzenback

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.


2018 ◽  
Vol 97 (8) ◽  
pp. 893-900 ◽  
Author(s):  
J. Papinska ◽  
H. Bagavant ◽  
G.B. Gmyrek ◽  
M. Sroka ◽  
S. Tummala ◽  
...  

Sjögren syndrome (SS), a chronic autoimmune disorder causing dry mouth, adversely affects the overall oral health in patients. Activation of innate immune responses and excessive production of type I interferons (IFNs) play a critical role in the pathogenesis of this disorder. Recognition of nucleic acids by cytosolic nucleic acid sensors is a major trigger for the induction of type I IFNs. Upon activation, cytosolic DNA sensors can interact with the stimulator of interferon genes (STING) protein, and activation of STING causes increased expression of type I IFNs. The role of STING activation in SS is not known. In this study, to investigate whether the cytosolic DNA sensing pathway influences SS development, female C57BL/6 mice were injected with a STING agonist, dimethylxanthenone-4-acetic acid (DMXAA). Salivary glands (SGs) were studied for gene expression and inflammatory cell infiltration. SG function was evaluated by measuring pilocarpine-induced salivation. Sera were analyzed for cytokines and autoantibodies. Primary SG cells were used to study the expression and activation of STING. Our data show that systemic DMXAA treatment rapidly induced the expression of Ifnb1, Il6, and Tnfa in the SGs, and these cytokines were also elevated in circulation. In contrast, increased Ifng gene expression was dominantly detected in the SGs. The type I innate lymphoid cells present within the SGs were the major source of IFN-γ, and their numbers increased significantly within 3 d of treatment. STING expression in SGs was mainly observed in ductal and interstitial cells. In primary SG cells, DMXAA activated STING and induced IFN-β production. The DMXAA-treated mice developed autoantibodies, sialoadenitis, and glandular hypofunction. Our study demonstrates that activation of the STING pathway holds the potential to initiate SS. Thus, apart from viral infections, conditions that cause cellular perturbations and accumulation of host DNA within the cytosol should also be considered as possible triggers for SS.


2019 ◽  
Author(s):  
Paulino Barragan-Iglesias ◽  
Úrzula Franco-Enzástiga ◽  
Vivekanand Jeevakumar ◽  
Andi Wangzhou ◽  
Vinicio Granados-Soto ◽  
...  

ABSTRACTOne of the first signs of viral infection is body-wide aches and pain. While this type of pain usually subsides, at the extreme, viral infections can induce painful neuropathies that can last for decades. Neither of these types of pain sensitization are well understood. A key part of the response to viral infection is production of interferons (IFNs), which then activate their specific receptors (IFNRs) resulting in downstream activation of cellular signaling and a variety of physiological responses. We sought to understand how type I IFNs (IFN-α and IFN-β) might act directly on nociceptors in the dorsal root ganglion (DRG) to cause pain sensitization. We demonstrate that type I IFNRs are expressed in small/medium DRG neurons and that their activation produces neuronal hyper-excitability and mechanical pain in mice. Type I IFNs stimulate JAK/STAT signaling in DRG neurons but this does not apparently result in PKR-eIF2α activation that normally induces an anti-viral response by limiting mRNA translation. Rather, type I interferons stimulate MNK-mediated eIF4E phosphorylation in DRG neurons to promote pain hypersensitivity. Endogenous release of type I IFNs with the double stranded RNA mimetic poly(I:C) likewise produces pain hypersensitivity that is blunted in mice lacking MNK-eIF4E signaling. Our findings reveal mechanisms through which type I IFNs cause nociceptor sensitization with implications for understanding how viral infections promote pain and can lead to neuropathies.SIGNIFICANCE STATEMENTIt is increasingly understood that pathogens interact with nociceptors to alert organisms to infection as well as to mount early host defenses. While specific mechanisms have been discovered for diverse bacteria and fungal pathogens, mechanisms engaged by viruses have remained elusive. Here we show that type 1 interferons, one of the first mediators produced by viral infection, act directly on nociceptors to produce pain sensitization. Type I interferons act via a specific signaling pathway (MNK-eIF4E signaling) that is known to produce nociceptor sensitization in inflammatory and neuropathic pain conditions. Our work reveals a mechanism through which viral infections cause heightened pain sensitivity


2021 ◽  
Author(s):  
Krystal J Vail ◽  
Bibiana Petri da Silveira ◽  
Samantha L Bell ◽  
Angela I Bordin ◽  
Noah D Cohen ◽  
...  

Rhodococcus equi is a major cause of foal pneumonia and an opportunistic pathogen in immunocompromised humans. While alveolar macrophages constitute the primary replicative niche for R. equi, little is known about how intracellular R. equi is sensed by macrophages. Here, we discovered that that in addition to previously characterized pro-inflammatory cytokines (e.g., Tnfa, Il6, Il1b), macrophages infected with R. equi induce a robust type I IFN response, including Ifnb and interferon-stimulated genes (ISGs), similar to the evolutionarily related pathogen, Mycobacterium tuberculosis. Follow up studies using a combination of mammalian and bacterial genetics, demonstrated that induction of this type I IFN expression program is largely dependent on the cGAS/STING/TBK1 axis of the cytosolic DNA surveillance pathway, suggesting that R. equi perturbs the phagosomal membrane and causes DNA release into the cytosol following phagocytosis. Consistent with this we found that a population of ~12% of R. equi phagosomes recruited the galectin-3, -8 and -9 danger receptors. Interesting, neither phagosomal damage nor induction of type I IFN required the R. equi's virulence-associated plasmid. Importantly, R. equi infection of both mice and foals stimulated ISG expression, in organs (mice) and circulating monocytes (foals). By demonstrating that R. equi activates cytosolic DNA sensing in macrophages and elicits type I IFN responses in animal models, our work provides novel insights into how R. equi engages the innate immune system and furthers our understanding how this zoonotic pathogen causes inflammation and disease.


2019 ◽  
Vol 51 (12) ◽  
pp. 1-9 ◽  
Author(s):  
Tae-Shin Kim ◽  
Eui-Cheol Shin

AbstractDuring viral infections, significant numbers of T cells are activated in a T cell receptor-independent and cytokine-dependent manner, a phenomenon referred to as “bystander activation.” Cytokines, including type I interferons, interleukin-18, and interleukin-15, are the most important factors that induce bystander activation of T cells, each of which plays a somewhat different role. Bystander T cells lack specificity for the pathogen, but can nevertheless impact the course of the immune response to the infection. For example, bystander-activated CD8+ T cells can participate in protective immunity by secreting cytokines, such as interferon-γ. They also mediate host injury by exerting cytotoxicity that is facilitated by natural killer cell-activating receptors, such as NKG2D, and cytolytic molecules, such as granzyme B. Interestingly, it has been recently reported that there is a strong association between the cytolytic function of bystander-activated CD8+ T cells and host tissue injury in patients with acute hepatitis A virus infection. The current review addresses the induction of bystander CD8+ T cells, their effector functions, and their potential roles in immunity to infection, immunopathology, and autoimmunity.


Lupus ◽  
2020 ◽  
Vol 29 (14) ◽  
pp. 1845-1853
Author(s):  
Jeffery Wei Heng Koh ◽  
Cheng Han Ng ◽  
Sen Hee Tay

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.


Sign in / Sign up

Export Citation Format

Share Document