scholarly journals Molecular Characterization, Expression and Functional Analysis of Chicken STING

2018 ◽  
Vol 19 (12) ◽  
pp. 3706 ◽  
Author(s):  
Jin-Shan Ran ◽  
Jie Jin ◽  
Xian-Xian Zhang ◽  
Ye Wang ◽  
Peng Ren ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Molecular Characterization ◽  
Poly I:C ◽  
Interferon Response ◽  
Type I ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Pathogen Invasion

Innate immunity is an essential line of defense against pathogen invasion which is gained at birth, and the mechanism involved is mainly to identify pathogen-associated molecular patterns through pattern recognition receptors. STING (stimulator of interferon genes) is a signal junction molecule that hosts the perception of viral nucleic acids and produces type I interferon response, which plays a crucial role in innate immunity. However, relatively few studies have investigated the molecular characterization, tissue distribution, and potential function of STING in chickens. In this study, we cloned the full-length cDNA of chicken STING that is composed of 1341 bp. Sequence analyses revealed that STING contains a 1140-bp open-reading frame that probably encodes a 379-amino acid protein. Multiple sequence alignments showed that the similarity of the chicken STING gene to other birds is higher than that of mammals. Real-time polymerase chain reaction (PCR) assays revealed that STING is highly expressed in the spleen, thymus and bursa of fabricious in chickens. Furthermore, we observed that STING expression was significantly upregulated both in vitro and in vivo following infection with Newcastle disease virus (NDV). STING expression was also significantly upregulated in chicken embryo fibroblasts upon stimulation with poly(I:C) or poly(dA:dT). Taken together, these findings suggest that STING plays an important role in antiviral signaling pathways in chickens.

scholarly journals Positive natural selection in primate genes of the type I interferon response

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elena N. Judd ◽  
Alison R. Gilchrist ◽  
Nicholas R. Meyerson ◽  
Sara L. Sawyer
Keyword(s):  
Natural Selection ◽  
Positive Selection ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Multiple Sequence Alignments ◽  
Interferon Stimulated Genes ◽  
Interferon Induction

Abstract Background The Type I interferon response is an important first-line defense against viruses. In turn, viruses antagonize (i.e., degrade, mis-localize, etc.) many proteins in interferon pathways. Thus, hosts and viruses are locked in an evolutionary arms race for dominance of the Type I interferon pathway. As a result, many genes in interferon pathways have experienced positive natural selection in favor of new allelic forms that can better recognize viruses or escape viral antagonists. Here, we performed a holistic analysis of selective pressures acting on genes in the Type I interferon family. We initially hypothesized that the genes responsible for inducing the production of interferon would be antagonized more heavily by viruses than genes that are turned on as a result of interferon. Our logic was that viruses would have greater effect if they worked upstream of the production of interferon molecules because, once interferon is produced, hundreds of interferon-stimulated proteins would activate and the virus would need to counteract them one-by-one. Results We curated multiple sequence alignments of primate orthologs for 131 genes active in interferon production and signaling (herein, “induction” genes), 100 interferon-stimulated genes, and 100 randomly chosen genes. We analyzed each multiple sequence alignment for the signatures of recurrent positive selection. Counter to our hypothesis, we found the interferon-stimulated genes, and not interferon induction genes, are evolving significantly more rapidly than a random set of genes. Interferon induction genes evolve in a way that is indistinguishable from a matched set of random genes (22% and 18% of genes bear signatures of positive selection, respectively). In contrast, interferon-stimulated genes evolve differently, with 33% of genes evolving under positive selection and containing a significantly higher fraction of codons that have experienced selection for recurrent replacement of the encoded amino acid. Conclusion Viruses may antagonize individual products of the interferon response more often than trying to neutralize the system altogether.

scholarly journals Development of Small-Molecule STING Activators for Cancer Immunotherapy

Biomedicines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Hee Ra Jung ◽  
Seongman Jo ◽  
Min Jae Jeon ◽  
Hyelim Lee ◽  
Yeonjeong Chu ◽  
...  
Keyword(s):  
Cancer Immunotherapy ◽  
Cyclic Gmp ◽  
Therapeutic Potential ◽  
Interferon Response ◽  
Type I ◽  
Anti Cancer ◽  
Cancer Agent ◽  
Sting Pathway

In cancer immunotherapy, the cyclic GMP–AMP synthase–stimulator of interferon genes (STING) pathway is an attractive target for switching the tumor immunophenotype from ‘cold’ to ‘hot’ through the activation of the type I interferon response. To develop a new chemical entity for STING activator to improve cyclic GMP-AMP (cGAMP)-induced innate immune response, we identified KAS-08 via the structural modification of DW2282, which was previously reported as an anti-cancer agent with an unknown mechanism. Further investigation revealed that direct STING binding or the enhanced phosphorylation of STING and downstream effectors were responsible for DW2282-or KAS-08-mediated STING activity. Furthermore, KAS-08 was validated as an effective STING pathway activator in vitro and in vivo. The synergistic effect of cGAMP-mediated immunity and efficient anti-cancer effects successfully demonstrated the therapeutic potential of KAS-08 for combination therapy in cancer treatment.

scholarly journals Interferon Regulatory Factor IRF-7 Induces the Antiviral Alpha Interferon Response and Protects against Lethal West Nile Virus Infection

2008 ◽  
Vol 82 (17) ◽  
pp. 8465-8475 ◽  
Author(s):  
Stephane Daffis ◽  
Melanie A. Samuel ◽  
Mehul S. Suthar ◽  
Brian C. Keller ◽  
Michael Gale ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Cortical Neurons ◽  
Interferon Regulatory Factor ◽  
Interferon Response ◽  
Type I ◽  
Type I Ifn ◽  
Regulatory Factor ◽  
West Nile

ABSTRACT Type I interferon (IFN-α/β) comprises a family of immunomodulatory cytokines that are critical for controlling viral infections. In cell culture, many RNA viruses trigger IFN responses through the binding of RNA recognition molecules (RIG-I, MDA5, and TLR-3) and induction of interferon regulatory factor IRF-3-dependent gene transcription. Recent studies with West Nile virus (WNV) have shown that type I IFN is essential for restricting infection and that a deficiency of IRF-3 results in enhanced lethality. However, IRF-3 was not required for optimal systemic IFN production in vivo or in vitro in macrophages. To begin to define the transcriptional factors that regulate type I IFN after WNV infection, we evaluated IFN induction and virus control in IRF-7−/− mice. Compared to congenic wild-type mice, IRF-7−/− mice showed increased lethality after WNV infection and developed early and elevated WNV burdens in both peripheral and central nervous system tissues. As a correlate, a deficiency of IRF-7 blunted the systemic type I IFN response in mice. Consistent with this, IFN-α gene expression and protein production were reduced and viral titers were increased in IRF-7−/− primary macrophages, fibroblasts, dendritic cells, and cortical neurons. In contrast, in these cells the IFN-β response remained largely intact. Our data suggest that the early protective IFN-α response against WNV occurs through an IRF-7-dependent transcriptional signal.

scholarly journals CX-5461 Treatment Leads to Cytosolic DNA-Mediated STING Activation in Ovarian Cancer

Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5056
Author(s):  
Robert Cornelison ◽  
Kuntal Biswas ◽  
Danielle C. Llaneza ◽  
Alexandra R. Harris ◽  
Nisha G. Sosale ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Time Frame ◽  
Interferon Response ◽  
Type I ◽  
Pol I ◽  
Downstream Effects ◽  
Immune Pathway ◽  
Polymerase I

Epithelial ovarian cancer (EOC) is the deadliest of the gynecologic malignancies, with an overall survival rate of <30%. Recent research has suggested that targeting RNA polymerase I (POL I) with small-molecule inhibitors may be a viable therapeutic approach to combating EOC, even when chemoresistance is present. CX-5461 is one of the most promising POL I inhibitors currently being investigated, and previous reports have shown that CX-5461 treatment induces DNA damage response (DDR) through ATM/ATR kinase. Investigation into downstream effects of CX-5461 led us to uncovering a previously unreported phenotype. Treatment with CX-5461 induces a rapid accumulation of cytosolic DNA. This accumulation leads to transcriptional upregulation of ‘STimulator of Interferon Genes’ (STING) in the same time frame, phosphorylation of IRF3, and activation of type I interferon response both in vitro and in vivo. This activation is mediated and dependent on cyclic GMP–AMP synthase (cGAS). Here, we show THAT CX-5461 leads to an accumulation of cytosolic dsDNA and thereby activates the cGAS–STING–TBK1–IRF3 innate immune pathway, which induces type I IFN. CX-5461 treatment-mediated immune activation may be a powerful mechanism of action to exploit, leading to novel drug combinations with a chance of increasing immunotherapy efficacy, possibly with some cancer specificity limiting deleterious toxicities.

scholarly journals Targeted Delivery of Chloroquine to Plasmacytoid Dendritic Cells Enhances Inhibition of the Type I Interferon Response

2021 ◽  
Author(s):  
Marilyn E Allen ◽  
Amit Golding ◽  
Violeta Rus ◽  
Nicholas B Karabin ◽  
Sophia Li ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Targeted Delivery ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Interferon Response ◽  
Type I ◽  
Healthy Human ◽  
Biodistribution Studies

Systemic lupus erythematosus (SLE) causes damaging inflammation in multiple organs via the accumulation of immune complexes. These complexes activate plasmacytoid DCs (pDCs) via TLR7 and TLR9, contributing to disease pathogenesis by driving secretion of inflammatory type I IFNs. Antimalarial drugs, such as chloroquine (CQ), are TLR antagonists used to alleviate inflammation in SLE. However, they require ~3 months of continuous use before achieving therapeutic efficacy and can accumulate in the retinal pigment epithelium with chronic use resulting in retinopathy. We hypothesized that poly(ethylene glycol)-b-poly(propylene sulfide) (PEG-b-PPS) filamentous nanocarriers, filomicelles (FMs) could improve drug activity and reduce toxicity by directly delivering CQ to pDCs via passive, morphology-based targeting. Healthy human PBMCs were treated with soluble CQ or CQ-loaded FMs, stimulated with TLR agonists or SLE patient sera, and type I IFN secretion was quantified via multi-subtype IFN-α ELISA and MX1 gene expression using real-time RT-qPCR. Our results showed that 50 µg CQ/mg FM decreased MX1 expression and IFN-α production after TLR activation with either synthetic nucleic acid agonists or immune complex rich sera from SLE patients. Cellular uptake and biodistribution studies showed that FMs preferentially accumulate in human pDCs in vitro and in tissues frequently damaged in SLE patients (i.e., liver and kidneys) while sparing the eye in vivo. These results showed that nanocarrier morphology enables drug delivery, and CQ-FMs may be equally effective and more targeted than soluble CQ at inhibiting SLE-relevant pathways.

In vivo administration of lentiviral vectors triggers a type I interferon response that restricts hepatocyte gene transfer and promotes vector clearance

Blood ◽  
2006 ◽  
Vol 109 (7) ◽  
pp. 2797-2805 ◽  
Author(s):  
Brian D. Brown ◽  
Giovanni Sitia ◽  
Andrea Annoni ◽  
Ehud Hauben ◽  
Lucia Sergi Sergi ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Transgene Expression ◽  
Lentiviral Vectors ◽  
Interferon Response ◽  
Type I ◽  
Nonparenchymal Cells ◽  
Antiviral Responses ◽  
Liver Gene

AbstractLiver gene transfer is a highly sought goal for the treatment of inherited and infectious diseases. Lentiviral vectors (LVs) have many desirable properties for hepatocyte-directed gene delivery, including the ability to integrate into nondividing cells. Unfortunately, upon systemic administration, LV transduces hepatocytes relatively inefficiently compared with nonparenchymal cells, and the duration of transgene expression is often limited by immune responses. Here, we investigated the role of innate antiviral responses in these events. We show that administration of LVs to mice triggers a rapid and transient IFNαβ response. This effect was dependent on functional vector particles, and in vitro challenge of antigen-presenting cells suggested that plasmacytoid dendritic cells initiated the response. Remarkably, when LVs were administered to animals that lack the capacity to respond to IFNαβ, there was a dramatic increase in hepatocyte transduction, and stable transgene expression was achieved. These findings indicate that, even in the setting of acute delivery of replication-defective vectors, IFNs effectively interfere with transduction in a cell-type–specific manner. Moreover, because disabling a single component of the innate/immune network was sufficient to establish persistent xenoantigen expression, our results raise the hope that the immunologic barriers to gene therapy are less insurmountable than expected.

scholarly journals Type I Interferon Response Limits Astrovirus Replication and Protects against Increased Barrier PermeabilityIn VitroandIn Vivo

2015 ◽  
Vol 90 (4) ◽  
pp. 1988-1996 ◽  
Author(s):  
Shauna A. Marvin ◽  
C. Theodore Huerta ◽  
Bridgett Sharp ◽  
Pamela Freiden ◽  
Troy D. Cline ◽  
...  
Keyword(s):  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Barrier Permeability ◽  
Type I Ifns ◽  
Human Astroviruses ◽  
Human Astrovirus ◽  
New Evidence

ABSTRACTLittle is known about intrinsic epithelial cell responses against astrovirus infection. Here we show that human astrovirus type 1 (HAstV-1) infection induces type I interferon (beta interferon [IFN-β]) production in differentiated Caco2 cells, which not only inhibits viral replication by blocking positive-strand viral RNA and capsid protein synthesis but also protects against HAstV-1-increased barrier permeability. Excitingly, we found similar resultsin vivousing a murine astrovirus (MuAstV) model, providing new evidence that virus-induced type I IFNs may protect against astrovirus replication and pathogenesisin vivo.IMPORTANCEHuman astroviruses are a major cause of pediatric diarrhea, yet little is known about the immune response. Here we show that type I interferon limits astrovirus infection and preserves barrier permeability bothin vitroandin vivo. Importantly, we characterized a new mouse model for studying astrovirus replication and pathogenesis.

scholarly journals A minimal RNA ligand for potent RIG-I activation in living mice

2017 ◽  
Author(s):  
Melissa M. Linehan ◽  
Thayne H. Dickey ◽  
Emanuela S. Molinari ◽  
Megan E. Fitzgerald ◽  
Olga Potapova ◽  
...  
Keyword(s):  
Immune System ◽  
Type I Interferons ◽  
Poly I:C ◽  
Interferon Response ◽  
Type I ◽  
Base Pairs ◽  
Stem Loop ◽  
Interferon Stimulated Genes ◽  
Rna Sensors

AbstractWe have developed highly potent synthetic activators of the vertebrate immune system that specifically target the RIG-I receptor. When introduced into mice, a family of short, triphosphorylated Stem Loop RNAs (SLRs) induces a potent interferon response and the activation of specific genes essential for antiviral defense. Using RNAseq, we provide the first in-vivo genome-wide view of the expression networks that are initiated upon RIG-I activation. We observe that SLRs specifically induce type I interferons, subsets of interferon-stimulated genes (ISGs), and cellular remodeling factors. By contrast, poly(I:C), which binds and activates multiple RNA sensors, induces type III interferons and several unique ISGs. The short length (10-14 base pairs) and robust function of SLRs in mice demonstrate that RIG-I forms active signaling complexes without oligomerizing on RNA. These findings demonstrate that SLRs are potent therapeutic and investigative tools for targeted modulation of the innate immune system.

scholarly journals Intracellular Lipid Droplet Accumulation Occurs Early Following Viral Infection and Is Required for an Efficient Interferon Response

2020 ◽  
Author(s):  
EA Monson ◽  
KM Crosse ◽  
M Duan ◽  
W Chen ◽  
RD O’Shea ◽  
...  
Keyword(s):  
Viral Replication ◽  
Viral Infection ◽  
Molecular Mechanisms ◽  
Viral Infections ◽  
Interferon Response ◽  
Type I ◽  
Antiviral Immune Response ◽  
Alternate Mechanism

SummaryLipid droplets (LDs) are increasingly recognized as critical organelles in signalling events, transient protein sequestration and inter-organelle interactions. However, the role LDs play in antiviral innate immune pathways remains unknown. Here we demonstrate that induction of LDs occurs as early as 2 hours post viral infection, is transient, and returns to basal levels by 72 hours. This phenomenon occurred following viral infections, both in vitro and in vivo. Virally driven LD induction was type-I interferon (IFN) independent, however, was dependent on EGFR engagement, offering an alternate mechanism of LD induction in comparison to our traditional understanding of their biogenesis. Additionally, LD induction corresponded with enhanced cellular type-I and -III IFN production in infected cells, with enhanced LD accumulation decreasing viral replication of both HSV-1 and Zika virus (ZIKV). Here, we demonstrate for the first time, that LDs play vital roles in facilitating the magnitude of the early antiviral immune response specifically through the enhanced modulation of IFN following viral infection, and control of viral replication. By identifying LDs as a critical signalling organelle, this data represents a paradigm shift in our understanding of the molecular mechanisms which coordinate an effective antiviral response.

scholarly journals PHR1 and PHR2 ofCandida albicans Encode Putative Glycosidases Required for Proper Cross-Linking of β-1,3- and β-1,6-Glucans

1999 ◽  
Vol 181 (22) ◽  
pp. 7070-7079 ◽  
Author(s):  
William A. Fonzi
Keyword(s):  
Temporal Analysis ◽  
Surface Proteins ◽  
Site Directed Mutagenesis ◽  
Cross Linking ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Fivefold Increase ◽  
Conditional Expression

ABSTRACT PHR1 and PHR2 encode putative glycosylphosphatidylinositol-anchored cell surface proteins of the opportunistic fungal pathogen Candida albicans. These proteins are functionally related, and their expression is modulated in relation to the pH of the ambient environment in vitro and in vivo. Deletion of either gene results in a pH-conditional defect in cell morphology and virulence. Multiple sequence alignments demonstrated a distant relationship between the Phr proteins and β-galactosidases. Based on this alignment, site-directed mutagenesis of the putative active-site residues of Phr1p and Phr2p was conducted and two conserved glutamate residues were shown to be essential for activity. By taking advantage of the pH-conditional expression of the genes, a temporal analysis of cell wall changes was performed following a shift of the mutants from permissive to nonpermissive pH. The mutations did not grossly affect the amount of polysaccharides in the wall but did alter their distribution. The most immediate alteration to occur was a fivefold increase in the rate of cross-linking between β-1,6-glycosylated mannoproteins and chitin. This increase was followed shortly thereafter by a decline in β-1,3-glucan-associated β-1,6-glucans and, within several generations, a fivefold increase in the chitin content of the walls. The increased accumulation of chitin-linked glucans was not due to a block in subsequent processing as determined by pulse-chase analysis. Rather, the results suggest that the glucans are diverted to chitin linkage due to the inability of the mutants to establish cross-links between β-1,6- and β-1,3-glucans. Based on these and previously published results, it is suggested that the Phr proteins process β-1,3-glucans and make available acceptor sites for the attachment of β-1,6-glucans.

Sign in / Sign up

Export Citation Format

Share Document