scholarly journals Activation of Stimulator of Interferon Genes (STING) and Sjögren Syndrome

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


2020 ◽  
Vol 11 ◽  
Author(s):  
Lindsey E. Fox ◽  
Marissa C. Locke ◽  
Deborah J. Lenschow

Type I interferons (IFNs) are critical effector cytokines of the immune system and were originally known for their important role in protecting against viral infections; however, they have more recently been shown to play protective or detrimental roles in many disease states. Type I IFNs consist of IFNα, IFNβ, IFNϵ, IFNκ, IFNω, and a few others, and they all signal through a shared receptor to exert a wide range of biological activities, including antiviral, antiproliferative, proapoptotic, and immunomodulatory effects. Though the individual type I IFN subtypes possess overlapping functions, there is growing appreciation that they also have unique properties. In this review, we summarize some of the mechanisms underlying differential expression of and signaling by type I IFNs, and we discuss examples of differential functions of IFNα and IFNβ in models of infectious disease, cancer, and autoimmunity.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1001-1001
Author(s):  
Valentina Nardi ◽  
Olaia Naveiras ◽  
Mohammad Azam ◽  
George Q. Daley

Abstract Until recently, the mainstay of Chronic Myelogenous Leukemia (CML) therapy was Interferon (IFN) alpha, which in a minority of patients induces long lasting cytogenetic remission. While the exact mechanism of action of IFN alpha in CML is still obscure, it is clear that the clinical response to IFN alpha correlates with immune system reactivity against leukemic clones. As minimal molecular disease often persists despite the use of imatinib and new Bcr-Abl inhibitors, immunotherapy remains an appealing adjunct to molecularly targeted inhibitors in CML therapy. We have shown that IRF8/ICSBP (Interferon Consensus Sequence Binding Protein) expression in Bcr-Abl transformed cells prevents their capacity to form a lethal leukemia when injected into mice, and that this protection is mediated by a long-lasting and potent CD8+ response against unknown epitopes on the leukemic cells. We hypothesized that the protection mediated by IRF8/ICSBP might be related to the anti-leukemic effects of IFN alpha. We now find that Type I IFNs like IFN alpha regulate IRF8/ICSBP expression in mouse and human cells and in Bcr-Abl transformed cells. Furthermore, type I IFNs can substitute for ICSBP in inducing the anti-leukemic immunity against Bcr-Abl transformed cells. Transcriptional profiling of cells expressing ICSBP, Bcr-Abl, or both ICSBP and Bcr-Abl identified two chemokines, CCL6 and CCL9, which were associated with the immune protection induced by IRF8/ICSBP expression. Type I IFNs and IRF8/ICSBP induce the expression of these chemokines in cells transformed with Bcr-Abl. RNAi-mediated inhibition experiments in our mouse model of CML show that these chemokines are required for the IRF8/ICSBP-mediated CD8+ anti-leukemic response to the Bcr-Abl transformed cells, suggesting that these chemokines could be exploited for immunotherapy in combination with existing Bcr-Abl peptide vaccines.


2010 ◽  
Vol 84 (21) ◽  
pp. 11045-11055 ◽  
Author(s):  
Deendayal Patel ◽  
Yuchen Nan ◽  
Meiyan Shen ◽  
Krit Ritthipichai ◽  
Xiaoping Zhu ◽  
...  

ABSTRACT Type I interferons (IFNs) IFN-α/β play an important role in innate immunity against viral infections by inducing antiviral responses. Porcine reproductive and respiratory syndrome virus (PRRSV) inhibits the synthesis of type I IFNs. However, whether PRRSV can inhibit IFN signaling is less well understood. In the present study, we found that PRRSV interferes with the IFN signaling pathway. The transcript levels of IFN-stimulated genes ISG15 and ISG56 and protein level of signal transducer and activator of transcription 2 (STAT2) in PRRSV VR2385-infected MARC-145 cells were significantly lower than those in mock-infected cells after IFN-α treatment. IFN-induced phosphorylation of both STAT1 and STAT2 and their heterodimer formation in the PRRSV-infected cells were not affected. However, the majority of the STAT1/STAT2/IRF9 (IFN regulatory factor 9) heterotrimers remained in the cytoplasm of PRRSV-infected cells, which indicates that the nuclear translocation of the heterotrimers was blocked. Overexpression of NSP1β of PRRSV VR2385 inhibited expression of ISG15 and ISG56 and blocked nuclear translocation of STAT1, which suggests that NSP1β might be the viral protein responsible for the inhibition of IFN signaling. PRRSV infection in primary porcine pulmonary alveolar macrophages (PAMs) also inhibited IFN-α-stimulated expression of the ISGs and the STAT2 protein. In contrast, a licensed low-virulence vaccine strain, Ingelvac PRRS modified live virus (MLV), activated expression of IFN-inducible genes, including those of chemokines and antiviral proteins, in PAMs without the addition of external IFN and had no detectable effect on IFN signaling. These findings suggest that PRRSV interferes with the activation and signaling pathway of type I IFNs by blocking ISG factor 3 (ISGF3) nuclear translocation.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Daisy X Ji ◽  
Kristen C Witt ◽  
Dmitri I Kotov ◽  
Shally R Margolis ◽  
Alexander Louie ◽  
...  

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.


Author(s):  
Daisy X. Ji ◽  
Kristen C. Witt ◽  
Dmitri I. Kotov ◽  
Shally R. Margolis ◽  
Alexander Louie ◽  
...  

AbstractType I interferons (IFNs) are essential for anti-viral immunity, but often impair protective immune responses during bacterial infections. How type I IFNs are strongly induced during viral infections, and yet are appropriately restrained during bacterial infections, remains poorly understood. The Super susceptibility to tuberculosis 1 (Sst1) locus in mice confers resistance to many bacterial infections. Here we provide evidence that Sp140 is a gene encoded within the Sst1 locus that functions to repress the expression of type I IFNs during bacterial infections. We generated Sp140−/− mice and find they are susceptible to infection by diverse bacteria, including Listeria monocytogenes, 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 repressor of type I IFNs that is essential for resistance to bacterial infections.


Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 94 ◽  
Author(s):  
Hongyan Guo ◽  
Anchun Cheng ◽  
Xingcui Zhang ◽  
YuHong Pan ◽  
Mingshu Wang ◽  
...  

Duck tembusu virus (DTMUV) is a single-stranded, positive-polarity RNA flavivirus that has caused considerable economic losses in China in recent years. Innate immunity represents the first line of defense against invading pathogens and serves as an important role in resisting viral infections. In this study, we found that the infection of ducks by DTMUV triggers Toll-like receptors (TLRs) and (RIG-I)-like receptors (RLRs) signaling pathways and inducing abundant of pro-inflammatory factors and type I interferons (IFNs), in which melanoma differentiation-associated gene 5 (MDA5) and Toll-like receptor 3 (TLR3) play important immunity roles, they can inhibit the replication process of DTMUV via inducing type I IFNs. Moreover, we demonstrated that type I IFNs can inhibit the DTMUV replication process in a time- and dose-dependent manner. Exosomes are small membrane vesicles that have important roles in intercellular communication. MicroRNAs (miRNAs) are small non-coding RNAs that can modulate gene expression and are common substances in exosomes. In our experiment, we successfully isolated DEF cells derived exosome for the first time and explored its function. Firstly, we found the expression of miR-148a-5p is significantly decreased following DTMUV infect. Then we found miR-148a-5p can target TLR3 and down-regulate the expression of TLR3, serving as a negative factor in innate immunity. Unfortunately, we cannot find miRNAs with different expression changes that can target MDA5. Lastly, our experimental results showed that TLR3 was one of the causes of miR-148a-5p reduction, suggesting that the high level of TLR3 after DTMUV infect can both trigger innate immunity and suppress miR-148a-5p to resist DTMUV.


2004 ◽  
Vol 200 (4) ◽  
pp. 437-445 ◽  
Author(s):  
Ryan M. O'Connell ◽  
Supriya K. Saha ◽  
Sagar A. Vaidya ◽  
Kevin W. Bruhn ◽  
Gustavo A. Miranda ◽  
...  

Numerous bacterial products such as lipopolysaccharide potently induce type I interferons (IFNs); however, the contribution of this innate response to host defense against bacterial infection remains unclear. Although mice deficient in either IFN regulatory factor (IRF)3 or the type I IFN receptor (IFNAR)1 are highly susceptible to viral infection, we show that these mice exhibit a profound resistance to infection caused by the Gram-positive intracellular bacterium Listeria monocytogenes compared with wild-type controls. Furthermore, this enhanced bacterial clearance is accompanied by a block in L. monocytogenes–induced splenic apoptosis in IRF3- and IFNAR1-deficient mice. Thus, our results highlight the disparate roles of type I IFNs during bacterial versus viral infections and stress the importance of proper IFN modulation in host defense.


2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Deann T. Snyder ◽  
Jodi F. Hedges ◽  
Mark A. Jutila

Type I interferons represent a unique and complex group of cytokines, serving many purposes during innate and adaptive immunity. Discovered in the context of viral infections, type I IFNs are now known to have myriad effects in infectious and autoimmune disease settings. Type I IFN signaling during bacterial infections is dependent on many factors including whether the infecting bacterium is intracellular or extracellular, as different signaling pathways are activated. As such, the repercussions of type I IFN induction can positively or negatively impact the disease outcome. This review focuses on type I IFN induction and downstream consequences during infection with the following intracellular bacteria:Chlamydia trachomatis,Listeria monocytogenes,Mycobacterium tuberculosis,Salmonella entericaserovar Typhimurium,Francisella tularensis,Brucella abortus,Legionella pneumophila, andCoxiella burnetii. Intracellular bacterial infections are unique because the bacteria must avoid, circumvent, and even co-opt microbial “sensing” mechanisms in order to reside and replicate within a host cell. Furthermore, life inside a host cell makes intracellular bacteria more difficult to target with antibiotics. Because type I IFNs are important immune effectors, modulating this pathway may improve disease outcomes. But first, it is critical to understand the context-dependent effects of the type I IFN pathway in intracellular bacterial infections.


2021 ◽  
Vol 22 (8) ◽  
pp. 4190
Author(s):  
Dóra Bencze ◽  
Tünde Fekete ◽  
Kitti Pázmándi

One of the most powerful and multifaceted cytokines produced by immune cells are type I interferons (IFNs), the basal secretion of which contributes to the maintenance of immune homeostasis, while their activation-induced production is essential to effective immune responses. Although, each cell is capable of producing type I IFNs, plasmacytoid dendritic cells (pDCs) possess a unique ability to rapidly produce large amounts of them. Importantly, type I IFNs have a prominent role in the pathomechanism of various pDC-associated diseases. Deficiency in type I IFN production increases the risk of more severe viral infections and the development of certain allergic reactions, and supports tumor resistance; nevertheless, its overproduction promotes autoimmune reactions. Therefore, the tight regulation of type I IFN responses of pDCs is essential to maintain an adequate level of immune response without causing adverse effects. Here, our goal was to summarize those endogenous factors that can influence the type I IFN responses of pDCs, and thus might serve as possible therapeutic targets in pDC-associated diseases. Furthermore, we briefly discuss the current therapeutic approaches targeting the pDC-type I IFN axis in viral infections, cancer, autoimmunity, and allergy, together with their limitations defined by the Janus-faced nature of pDC-derived type I IFNs.


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