scholarly journals Enhancing innate antiviral immune responses in rainbow trout by double stranded RNA delivered with cationic phytoglycogen nanoparticles

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tamiru N. Alkie ◽  
Jondavid de Jong ◽  
Kristof Jenik ◽  
Karl M. Klinger ◽  
Stephanie J. DeWitte-Orr
Keyword(s):  
Rainbow Trout ◽  
Immune Responses ◽  
Cell Line ◽  
Culture Conditions ◽  
Type I Interferons ◽  
Poly I:C ◽  
Synthetic Analogue ◽  
Type I ◽  
Viral Dsrna

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.

scholarly journals Regulation of TRIF-mediated innate immune response by K27-linked polyubiquitination and deubiquitination

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xin Wu ◽  
Caoqi Lei ◽  
Tian Xia ◽  
Xuan Zhong ◽  
Qing Yang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Adaptor Protein ◽  
Innate Immune ◽  
Negative Regulator ◽  
Type I Interferons ◽  
Poly I:C ◽  
Type I ◽  
Innate Immune Responses

Abstract TIR domain-containing adaptor inducing interferon-β (TRIF) is an essential adaptor protein required for innate immune responses mediated by Toll-like receptor (TLR) 3- and TLR4. Here we identify USP19 as a negative regulator of TLR3/4-mediated signaling. USP19 deficiency increases the production of type I interferons (IFN) and proinflammatory cytokines induced by poly(I:C) or LPS in vitro and in vivo. Usp19-/- mice have more serious inflammation after poly(I:C) or LPS treatment, and are more susceptible to inflammatory damages and death following Salmonella typhimurium infection. Mechanistically, USP19 interacts with TRIF and catalyzes the removal of TRIF K27-linked polyubiquitin moieties, thereby impairing the recruitment of TRIF to TLR3/4. In addition, the RING E3 ubiquitin ligase complex Cullin-3-Rbx1-KCTD10 catalyzes K27-linked polyubiquitination of TRIF at K523, and deficiency of this complex inhibits TLR3/4-mediated innate immune signaling. Our findings thus reveal TRIF K27-linked polyubiquitination and deubiquitination as a critical regulatory mechanism of TLR3/4-mediated innate immune responses.

Epigenetic regulation of frog innate immunity: Discovery of frog microRNAs associated with antiviral responses and ranavirus infection using a Xenopus laevis skin epithelial-like cell line

2021 ◽  
Author(s):  
Lauren A. Todd ◽  
Maxwell P. Bui-Marinos ◽  
Barbara A. Katzenback
Keyword(s):  
Xenopus Laevis ◽  
Cell Line ◽  
Antiviral Immunity ◽  
Type I Interferons ◽  
Poly I:C ◽  
Type I ◽  
Frog Virus ◽  
Interferon Stimulated Genes ◽  
Antiviral Responses ◽  
Innate Antiviral Immunity

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.

scholarly journals Post-transcriptional regulation of frog innate immunity: discovery of frog microRNAs associated with antiviral responses and ranavirus infection using a Xenopus laevis skin epithelial-like cell line

FACETS ◽  
2021 ◽  
Vol 6 ◽  
pp. 2058-2083
Author(s):  
Lauren A. Todd ◽  
Maxwell P. Bui-Marinos ◽  
Barbara A. Katzenback
Keyword(s):  
Xenopus Laevis ◽  
Cell Line ◽  
Antiviral Immunity ◽  
Type I Interferons ◽  
Poly I:C ◽  
Type I ◽  
Frog Virus ◽  
Interferon Stimulated Genes ◽  
Antiviral Responses ◽  
Innate Antiviral Immunity

Post-transcriptional 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 viral double-stranded RNA and inducer of type I interferons—or frog virus 3 (FV3), an immunoevasive virus associated with amphibian mortality events. Small RNA libraries generated from untreated, poly(I:C)-treated, and FV3-infected cells were sequenced. 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-ĸB-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.

scholarly journals Role of Type I Interferons on Filovirus Pathogenesis

Vaccines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 22 ◽  
Author(s):  
Beatriz Escudero-Pérez ◽  
César Muñoz-Fontela
Keyword(s):  
Animal Models ◽  
Immune Responses ◽  
Marburg Virus ◽  
Type I Interferons ◽  
Type I ◽  
Adaptive Immune ◽  
Antigen Presenting

Filoviruses, such as Ebola and Marburg virus, encode viral proteins with the ability to counteract the type I interferon (IFN-I) response. These IFN-I antagonist proteins are crucial to ensure virus replication, prevent an antiviral state in infected and bystander cells, and impair the ability of antigen-presenting cells to initiate adaptive immune responses. However, in recent years, a number of studies have underscored the conflicting data between in vitro studies and in vivo data obtained in animal models and clinical studies during outbreaks. This review aims to summarize these data and to discuss the relative contributions of IFN-α and IFN-β to filovirus pathogenesis in animal models and humans. Finally, we evaluate the putative utilization of IFN-I in post-exposure therapy and its implications as a biomarker of vaccine efficacy.

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 ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Viral Infections ◽  
Type I Interferons ◽  
Poly I:C ◽  
Synthetic Analogue ◽  
Type I ◽  
Platelet Production ◽  
Underlying Mechanisms ◽  
And Function

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.

scholarly journals Cellular uptake of extracellular nucleosomes induces innate immune responses by binding and activating cGMP-AMP synthase (cGAS)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Huawei Wang ◽  
Chuanlong Zang ◽  
Mengtian Ren ◽  
Mengdi Shang ◽  
Zhenghua Wang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Autoimmune Diseases ◽  
Mammalian Cells ◽  
Circulatory System ◽  
Type I Interferons ◽  
Type I ◽  
Binding Affinities ◽  
Innate Immune Responses ◽  
Monocytic Cells

Abstract The nucleosome is the basic structural repeating unit of chromatin. DNA damage and cell apoptosis release nucleosomes into the blood circulatory system, and increased levels of circulating nucleosomes have been observed to be related to inflammation and autoimmune diseases. However, how circulating nucleosomes trigger immune responses has not been fully elucidated. cGAS (cGMP-AMP synthase) is a recently discovered pattern recognition receptor that senses cytoplasmic double-stranded DNA (dsDNA). In this study, we employed in vitro reconstituted nucleosomes to examine whether extracellular nucleosomes can gain access to the cytoplasm of mammalian cells to induce immune responses by activating cGAS. We showed that nucleosomes can be taken up by various mammalian cells. Additionally, we found that in vitro reconstituted mononucleosomes and oligonucleosomes can be recognized by cGAS. Compared to dsDNA, nucleosomes exhibit higher binding affinities to cGAS but considerably lower potency in cGAS activation. Incubation of monocytic cells with reconstituted nucleosomes leads to limited production of type I interferons and proinflammatory cytokines via a cGAS-dependent mechanism. This proof-of-concept study reveals the cGAS-dependent immunogenicity of nucleosomes and highlights the potential roles of circulating nucleosomes in autoimmune diseases, inflammation, and antitumour immunity.

scholarly journals Mouse primary microglia respond differently to LPS and poly(I:C) in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yingbo He ◽  
Natalie Taylor ◽  
Xiang Yao ◽  
Anindya Bhattacharya
Keyword(s):  
Microglial Activation ◽  
Poly I:C ◽  
Type I ◽  
Primary Microglia ◽  
Viral Dsrna ◽  
Functional Differences ◽  
Genome Wide ◽  
Gene Level ◽  
Signal Cascades

AbstractMicroglia, CNS resident innate immune cells, respond strongly to activation of TLR3 and TLR4, which recognize viral dsRNA poly(I:C) and bacterial endotoxin LPS, respectively. However, few studies have thoroughly and parallelly compared functional phenotypes and downstream mechanisms between LPS- and poly(I:C)-exposed primary microglia. Here, we investigated the responses of mouse primary microglia upon LPS and poly(I:C) stimulation by detecting various phenotypes ranging from morphology, proliferation, secretion, chemotaxis, to phagocytosis. Furthermore, we explored their sequential gene expression and the downstream signal cascades. Interestingly, we found that the microglial activation pattern induced by LPS was distinguished from that induced by poly(I:C). Regarding microglial morphology, LPS caused an ameboid-like shape while poly(I:C) induced a bushy shape. Microglial proliferation was also facilitated by LPS but not by poly(I:C). In addition, LPS and poly(I:C) modulated microglial chemotaxis and phagocytosis differently. Furthermore, genome-wide analysis provided gene-level support to these functional differences, which may be associated with NF-κb and type I interferon pathways. Last, LPS- and poly(I:C)-activated microglia mediated neurotoxicity in a co-culture system. This study extends our understanding of TLR roles in microglia and provides insights into selecting proper inflammatory microglial models, which may facilitate identification of new targets for therapeutic application.

Type I Interferons promote maintenance and function of follicular T helper cells in vitro

2019 ◽  
Author(s):  
S Ehrlich ◽  
K Wild ◽  
M Smits ◽  
K Zoldan ◽  
M Hofmann ◽  
...  
Keyword(s):  
T Helper Cells ◽  
Type I Interferons ◽  
Type I ◽  
T Helper ◽  
Helper Cells ◽  
Follicular T Helper Cells ◽  
And Function

Immune responses of porcine airway epithelial cells to poly(I:C), a synthetic analogue of viral double-stranded RNA

2015 ◽  
Vol 95 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Xiu-qin Yang ◽  
Liang Wang ◽  
Hai-tao Li ◽  
Di Liu
Keyword(s):  
Epithelial Cells ◽  
Immune Responses ◽  
Digital Gene Expression ◽  
Enrichment Analysis ◽  
Airway Epithelial Cells ◽  
Poly I:C ◽  
Synthetic Analogue ◽  
Airway Epithelial ◽  
Transcriptional Responses ◽  
Double Stranded Rna

Yang, X.-q., Wang, L., Li, H.-t. and Liu, D. 2015. Immune responses of porcine airway epithelial cells to poly(I:C), a synthetic analogue of viral double-stranded RNA. Can. J. Anim. Sci. 95: 13–20. Swine respiratory disease (SRD) is one of the most economically important diseases affecting the pig industry. The main infectious agents that cause SRD are viruses, but the molecular pathogenesis of viral SRD has not been extensively studied. Here, using digital gene expression tag profiling, the global transcriptional responses to poly(I:C), a synthetic analogue of viral double-stranded RNA, was analyzed in porcine airway epithelial cells (PAECs). The profiling analysis revealed numerous differentially expressed genes (DEGs), including unknown sequences in the porcine nucleotide databases. Gene ontology enrichment analysis showed that DEGs were mainly enriched in response to stress (GO: 0006950), of which, defense response is one sub-process. Poly(I:C) challenge induced a general inflammation response as indicated by marked upregulation of a variety of pathogen recognition receptors, interferon-stimulated genes, proinflammatory cytokines, and chemokines, together with the significant downregulation of anti-inflammatory molecules. Furthermore, the antiapoptotic pathway was triggered, as demonstrated by the significant suppression of molecules involved in the induction of apoptosis, together with the significant stimulation of putative inhibitor of apoptosis. The results indicate that PAECs initiated defense against poly(I:C) challenge through the inflammation responses, whereas poly(I:C) can utilize antiapoptotic pathway to evade host defense.

scholarly journals Extrachromosomal Histone H2B Mediates Innate Antiviral Immune Responses Induced by Intracellular Double-Stranded DNA

2009 ◽  
Vol 84 (2) ◽  
pp. 822-832 ◽  
Author(s):  
Kouji Kobiyama ◽  
Fumihiko Takeshita ◽  
Nao Jounai ◽  
Asako Sakaue-Sawano ◽  
Atsushi Miyawaki ◽  
...  
Keyword(s):  
Immune Responses ◽  
Rna Virus ◽  
Cellular Signaling ◽  
Helical Structure ◽  
Human Cells ◽  
Type I Interferons ◽  
Type I ◽  
Histone H2b ◽  
Dna Viruses ◽  
Double Stranded Dna

ABSTRACT Fragments of double-stranded DNA (dsDNA) forming a right-handed helical structure (B-DNA) stimulate cells to produce type I interferons (IFNs). While an adaptor molecule, IFN-β promoter stimulator 1 (IPS-1), mediates dsDNA-induced cellular signaling in human cells, the underlying molecular mechanism is not fully understood. Here, we demonstrate that the extrachromosomal histone H2B mediates innate antiviral immune responses in human cells. H2B physically interacts with IPS-1 through the association with a newly identified adaptor, CIAO (COOH-terminal importin 9-related adaptor organizing histone H2B and IPS-1), to transmit the cellular signaling for dsDNA but not immunostimulatory RNA. Extrachromosomal histone H2B was biologically crucial for cell-autonomous responses to protect against multiplication of DNA viruses but not an RNA virus. Thus, the present findings provide evidence indicating that the extrachromosomal histone H2B is engaged in the signaling pathway initiated by dsDNA to trigger antiviral innate immune responses.

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