Poly (I:C) downregulates platelet production and function through type I interferon

2015 ◽  
Vol 114 (11) ◽  
pp. 982-993 ◽  
Author(s):  
Leonardo Rivadeneyra ◽  
Roberto Gabriel Pozner ◽  
Roberto Meiss ◽  
Carlos Fondevila ◽  
Ricardo Martin Gómez ◽  
...  

SummaryThrombocytopenia is a frequent complication of viral infections; the underlying mechanisms appear to depend on the identity of the virus involved. Previous research, including reports from our group, indicates that as well as having antiviral activity type I interferons (IFN I) selectively downregulate platelet production. In this study we extended understanding of the role of endogenous IFN I in megakaryo/ thrombopoiesis by evaluating platelet and megakaryocyte physiology in mice treated with polyinosinic:polycytidylic acid [poly (I:C)], a synthetic analogue of double-stranded RNA, Toll-like receptor-3 ligand and strong IFNp inducer. Mice-treated with poly (I:C) showed thrombocytopaenia, an increase in mean platelet volume and abnormal haemostatic and inflammatory platelet-mediated functionality, indicated by decreased fibrinogen binding and platelet adhesion, prolonged tail bleeding times and impaired P-Selectin externalisation, RANTES release and thrombin-induced platelet-neutrophil aggregate formation. These changes were associated with an increase in size and an abnormal distribution of bone marrow megakaryocytes within the vascular niche and were directly correlated with the plasmatic and bone marrow IFNp levels. All these effects were absent in genetically modified mice lacking the IFN I receptor. Our results suggest that IFN I is the central mediator of poly (I:C)-induced thrombocytopenia and platelet dysfunction and indicate that these abnormalities are due to changes in the last stages of megakaryocyte development. These data provide new evidence for the role of IFN I in megakaryocyte distribution in the bone marrow niches and its influence on thrombopoiesis and haemostasis.

2014 ◽  
Vol 8 ◽  
Author(s):  
Murray Carol ◽  
O Loughlin Elaine ◽  
Cunningham Colm

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


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tamiru N. Alkie ◽  
Jondavid de Jong ◽  
Kristof Jenik ◽  
Karl M. Klinger ◽  
Stephanie J. DeWitte-Orr

Abstract Innate immunity is induced when pathogen-associated molecular patterns (PAMPs) bind host pattern recognition receptors (PRRs). Polyinosinic:polycytidylic acid [poly(I:C)] is a synthetic analogue of viral dsRNA that acts as a PAMP, inducing type I interferons (IFNs) in vertebrates. In the present study, the immunostimulatory effects of high molecular weight (HMW) poly(I:C) in rainbow trout cells were measured when bound to a cationic phytoglycogen nanoparticle (Nano-HMW). The physical characteristics of the nanoparticle itself, when bound to different lengths of dsRNA and when cell associated was evaluated. Optimal concentration and timing for innate immune stimulation was measured using the RTG-P1 reporter cell line. The immunostimulatory effects of HMW poly (I:C) was compared to Nano-HMW in vitro using the RTgutGC cell line cultured in a conventional monolayer or a transwell culture system. The ability of an activated intestinal epithelium to transmit an antiviral signal to macrophages was evaluated using a co-culture of RTgutGC cells and RTSll (a monocyte/macrophage cell). In all culture conditions, Nano-HMW was a more effective inducer of IFN-related antiviral immune responses compared to HMW poly (I:C) alone. This study introduces the use of cationic phytoglycogen nanoparticles as a novel delivery system for immunomodulatory molecules to enhance immune responses in aquatic vertebrates.


2004 ◽  
Vol 202 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Christian Bogdan ◽  
Jochen Mattner ◽  
Ulrike Schleicher

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.


2020 ◽  
Author(s):  
Caitlin K. Posillico ◽  
Rosa E. Garcia-Hernandez ◽  
Natalie C. Tronson

ABSTRACTThe neuroimmune system is required for normal neural processes, including modulation of cognition, emotion, and adaptive behaviors. Aberrant neuroimmune activation is associated with dysregulation of memory and emotion, though the precise mechanisms at play are complex and highly context dependent. Sex differences neuroimmune activation and function further complicate our understanding of its roles in cognitive and affective regulation. Here, we characterized the physiological sickness and inflammatory response of the hippocampus following intracerebroventricular (ICV) administration of a synthetic viral mimic, polyinosinic:polycytidylic acid (poly I:C), in both male and female C57Bl/6 mice. We observed that poly I:C induced weight loss, fever, and elevations of cytokine and chemokines in the hippocampus of both sexes. Specifically, we found transient increases in gene expression and protein levels of IL-1a, IL-1β, IL-4, IL-6, TNFa, CCL2, and CXCL10, where males showed a greater magnitude of response compared with females. Only males showed increased IFNa and IFNγ in response to poly I:C, whereas both males and females exhibited elevations of IFNβ, demonstrating a specific sex difference in the anti-viral response in the hippocampus. This suggests that type I interferons are one potential node mediating sex-specific cytokine responses and neuroimmune effects on synaptic plasticity and cognition. These findings highlight the importance of using both males and females and analyzing a broad set of inflammatory markers in order to identify the precise, sex-specific roles for neuroimmune dysregulation in neurological diseases and disorders including Alzheimer’s Disease and depression.


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 12 ◽  
Author(s):  
Qinzhi Yang ◽  
Fang Lin ◽  
Yanan Wang ◽  
Min Zeng ◽  
Mao Luo

Coronavirus disease 2019 (COVID-19), which has high incidence rates with rapid rate of transmission, is a pandemic that spread across the world, resulting in more than 3,000,000 deaths globally. Currently, several drugs have been used for the clinical treatment of COVID-19, such as antivirals (radecivir, baritinib), monoclonal antibodies (tocilizumab), and glucocorticoids (dexamethasone). Accumulating evidence indicates that long noncoding RNAs (lncRNAs) are essential regulators of virus infections and antiviral immune responses including biological processes that are involved in the regulation of COVID-19 and subsequent disease states. Upon viral infections, cellular lncRNAs directly regulate viral genes and influence viral replication and pathology through virus-mediated changes in the host transcriptome. Additionally, several host lncRNAs could help the occurrence of viral immune escape by inhibiting type I interferons (IFN-1), while others could up-regulate IFN-1 production to play an antiviral role. Consequently, understanding the expression and function of lncRNAs during severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection will provide insights into the development of lncRNA-based methods. In this review, we summarized the current findings of lncRNAs in the regulation of the strong inflammatory response, immune dysfunction and thrombosis induced by SARS-CoV-2 infection, discussed the underlying mechanisms, and highlighted the therapeutic challenges of COVID-19 treatment and its future research directions.


2021 ◽  
Author(s):  
Jimin Yoon ◽  
Min-Seok Lee ◽  
Ahsan Ausaf Ali ◽  
Ye Rim Oh ◽  
Yong Seok Choi ◽  
...  

AbstractSjӧgren’s syndrome (SS) is a systemic autoimmune disease that targets the exocrine glands, resulting in impaired saliva and tear secretion. To date, type I interferons (IFNs) are increasingly recognized as pivotal mediators in SS, but their endogenous drivers have not been elucidated. Here, we investigate the role of mitochondrial double-stranded RNAs (mt-dsRNAs) in regulating type I IFN response in SS. We find that mt-dsRNAs are elevated in the saliva and tear of SS patients and in salivary glands of non-obese diabetic mice with salivary dysfunction. Using the in-house- developed 3D culture, we show that dsRNA stimulation increases mt-dsRNAs expression via JAK1/STAT pathway and facilitates their cytosolic export, which is accompanied by autoimmune signatures observed in SS. We further show that muscarinic receptor ligand acetylcholine or antioxidant resveratrol ameliorates autoimmune characteristics by preventing mt-dsRNA- mediated immune activation. In addition, direct suppression of mt-dsRNAs reverses the autoimmune signatures of SS. Altogether, our study underscores the significance of mt-dsRNA upregulation and suggests mt-dsRNAs as an important key to the puzzle of SS.SummaryMitochondrial double-stranded RNA levels are elevated in the tear and saliva of SS patients. These RNAs promote type I interferon signature, as well as other autoimmune phenotypes in SS. Downregulation of mitochondrial dsRNAs alleviates autoimmune signatures of SS in salivary gland epithelial cells.Graphical Abstractmt-dsRNAs as the molecular mediator of autoimmune phenotypes in SS.mt-dsRNAs are elevated in both human samples and mouse model of SS and function to exacerbate dsRNA-induced autoimmune phenotypes in SS. Countering the accumulation of mt- dsRNAs alleviates the autoimmune phenotypes in SGECs.


2019 ◽  
Vol 20 (18) ◽  
pp. 4410 ◽  
Author(s):  
Magdalena Howe ◽  
Jens Bauer ◽  
Anja Schulze ◽  
Sonja Kropp ◽  
Richard M. Locksley ◽  
...  

Viral infections are associated with increased incidence of severe sepsis. Particularly during the early stages, type I interferons (IFNs) are known mediators of detrimental effects. However, the functional role of early interferon β (IFNβ) and its cellular source during sepsis in the context of preexisting viral infections has not been defined. Using the colon ascendens stent peritonitis (CASP) model, we demonstrate that IFNβ−/− and type I IFN receptor (IFNAR1)−/− mice were less susceptible to sepsis after pre-stimulation with the viral mimetic poly(I:C). Wild type (WT) mice treated with poly(I:C) exhibited altered expression patterns of TNF and IL-12p40 during CASP which were dependent on IFNβ or IFNAR1, suggesting a mechanism for the increased sepsis susceptibility of WT mice. Using a double cytokine reporter mouse model, we present novel data on the simultaneous expression of IFNβ and IL-12p40 on a single cell level during polymicrobial sepsis in vivo. Conventional dendritic cells (cDCs) were identified as primary source of IFNβ and the protective cytokine IL-12p40 after CASP surgery irrespective of poly(I:C) pre-stimulation. These data demonstrated that if polymicrobial sepsis is preceded by a viral infection, IFNβ and IL-12p40 are expressed by polyfunctional cDCs suggesting that these cells can play both detrimental and beneficial roles during sepsis development.


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