Short duplex RNAs induce potent immunostimulation via Hoogsteen G-G base pairing-mediated dimerization
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE181827 | GEO | 2021/08/12
REPOSITORIES: GEO
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Project description:Here we describe a new class of immunostimulatory short duplex RNAs that potently induce production of type I interferon (IFN-I), and particularly IFN-β, in a wide range ofhuman cell types via end-to-end dimerization, direct binding to RIG-I, and activation of the RIG-I/IRF3 pathway. These RNAs require a minimum of 20 base pairs, lack any sequence or structural characteristics of known immunostimulatory RNAs, and instead require a unique conserved sequence motif (sense strand: 5’-C, antisense strand: 3’-GGG) that mediates the self-assembly of end-to-end RNA dimers by Hoogsteen G-G base-pairing. The presence of terminal hydroxyl or monophosphate groups, blunt or overhanging ends, or terminal RNA or DNA bases also did not affect their ability to induce IFN-I production. Immune stimulation mediated by these duplex RNAs results in broad spectrum inhibition of infections by many respiratory viruses with pandemic potential, including SARS-CoV-2, SARS-CoV, MERS-CoV, and influenza A, as well as the common cold virus HCoV-NL63 in cell lines and in human Lung Chips that mimic organlevel lung pathophysiology. These novel immunostimulatory motifs potentially could be harnessed to create broad-spectrum antiviral therapeutics, but they should be avoided when designing siRNAs to minimize immunological side effects.
2022-09-01 | PXD027838 | Pride
Project description:Background: Type I interferons (IFNs) are essential to the clearance of viral diseases, in part by initiating upregulation of IFN regulated genes (IRGs). A clear distinction between genes upregulated directly by virus and genes upregulated by secondary IFN production has not been made. Here we investigated the genes regulated by IFN-a2b compared to the genes regulated by SARS-CoV infection in ferrets. Methods: We characterized early host immune responses in peripheral blood and lung necropsies of ferrets injected with IFN-a2b or infected with SARS-CoV/Tor 2 strain, using microarray analysis on the Affymetrix platform. Results: We identified a common IRG signature that was upregulated in both SARS-CoV infected ferrets as well as in ferrets injected with IFN-a2b. We also identified unique patterns of gene expression for leukocyte activation, cell adhesion and complement pathways between IFN-a2b injection and SARS-CoV infection. Conclusions: Our results define the effects of IFN-a2b on the immune system of ferrets highlighting genes regulated by IFN during SARS-CoV infection. We have shown the similarities and differences of top funcional gene groups as well as pathways that play key roles in early immune responses in ferrets in response to IFN-a2b or SARS-CoV. Key words: ferret, gene expression, SARS, interferon. Keywords: time course In experiments with IFN-a2b, for peripheral blood, 15 ferrets were randomly allocated to 3 groups: Day 0, 5 ferrets (no IFN injection), day 1, 6 ferrets (injected), and day 2, 4 ferrets (injected). For lung necropsies of injected ferrets with IFN-a2b, we used 12 ferrets in 3 groups: 4 ferrets, day 0 (no IFN injection), 4 ferrets, day 1 (injected) and 4 ferrets, day 2 (injected). Experimental groups for SARS-CoV infection was as follows: For peripheral blood, 3 and 4 ferrets for day 0 (no infection) and day 2 (infection) respectively. For lung neceropsies, a total of 9 ferrets in 3 groups, each with 3 replicates for day 0 (no infection), day 1 (infection) and day 2 (infection).
2010-12-01 | E-GEOD-22581 | biostudies-arrayexpress
Project description:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (COVID-19) has caused a global health emergency. A key feature of COVID-19 is dysregulated Interferon-response. Type-I interferon (IFN-I) is one of the earliest antiviral innate immune responses following viral infection and plays a significant role in pathogenesis of SARS-CoV-2. In this study, using a proteomics-based approach, we identified that SARS-CoV-2 infection induces delayed and dysregulated IFN-I signaling in Huh7 cells. We demonstrate that SARS-CoV-2 is able to inhibit RIG-I mediated IFN- production. Our results also confirm the recent findings that IFN-I pretreatment is able to reduce susceptibility of Huh7 cells to SARS-CoV-2, but not post-treatment. Senescent Huh7 cells in spite of showing accentuated IFN-I response were more susceptible to SARS-CoV-2 infection and SARS-CoV-2 effectively inhibited IFIT1 in these cells. Proteomic comparison between SARS-CoV-2, SARS-CoV and MERS-CoV revealed a distinct differential regulatory signature of interferon-related proteins emphasizing that therapeutic strategies based on observations in SARS-CoV and MERS-CoV should be used with caution. Our findings provide a better understanding of SARS-CoV-2 regulation of cellular interferon response and a perspective on its use as a treatment. Characterization of the role of different interferon stimulated genes on the inhibition of SARS-CoV-2 pathogenesis may direct novel antiviral strategies.
2021-05-18 | PXD023450 | Pride
Project description:Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) infection causes an immune-mediated disease. We have recently shown that SARS-CoV-induced epithelial Calu-3 cytokines could exacerbate and dampen host inflammatory and T cell responses, respectively, through modulating the functions of macrophages and dendritic cells, thereby suggesting that not only are lung epithelial cells the primary cells of SARS-CoV infection, but they also involve in initiating and orchestrating the host innate and adaptive immunity. Comprehensive evaluation of the complex epithelial signaling to SARS-CoV is, thus, crucial for paving the way to better understand SARS pathogenesis and develop the innovative therapeutics against SARS. Here, based on the microarray-based functional genomics, we reported that 2B4 cells, a clonal derivative of Calu-3 cells, elicited a temporal and spatial activation of nuclear factor (NF)kappaB, activator protein (AP)-1 (ATF2/c-Jun), and interferon regulatory factor (IRF)-3/-7 at 12-, 24-, and 48-hrs post infection (p.i.), respectively, resulting in the activation of many antiviral genes, including interferon (IFN)-β, -λs, SARS-related inflammatory mediators, and various IFN-stimulated genes (ISGs). While elevated responses of IFN-β and IFN-λs were not detected until 48-hrs p.i., as a consequence of a delayed IRF-3/-7 activation, we showed, for the first time, that both types of IFNs exerted previously under-described non-redundant, complementary, and/or synergistic effects on the epithelial defense against SARS-CoV. Collectively, our results highlight the molecular mechanisms of the sequential activation of virus- and IFN-dependent signaling of lung epithelial cells against SARS-CoV and identify novel cellular targets for future studies, aiming at advancing strategies against SARS. DNA microarrays were performed in the Molecular Genomics (MG) Core Facilities at UTMB. The detailed information about the procedures of microarray analysis has been posted on the MG Core Facilities website (genomics@scms.utmb.edu). To characterize the dynamic, spatial, and temporal changes of the gene expression induced by SARS-CoV, confluent 2B4 cells grown in T-75 flasks were infected with SARS-CoV (MOI=0.1) or remained uninfected (as control) for 12, 24, and 48hrs. Because 2B4 cells were also permissive to the productive infection of Dhori virus (DHOV), a member of the Orthomyxoviridae family within the Thogotovirus genus, resulting in robust responses of IFNs and other pro-inflammatory mediators, we also established parallel cultures of DHOV-infected 2B4 cells (MOI=0.1) for the comparative analysis of global gene expression elicited by SARS-CoV- versus DHOV-infected 2B4 cells. To meet the minimal number required for application of statistical algorithms, we performed the study in triplicate at each time point for mock-, SARS-CoV-, and DHOV-infected cultures, yielding a total of 27 arrays. Briefly, supernatants were harvested from differentially treated cultures at 12-, 24-, and 48-hrs p.i. for subsequent analyses of viral yields and cytokine profiling, whereas the cells were subjected to total RNA extraction by using an RNAqueous-4PCR kit and following the protocol recommended by the manufacturer (Ambion, Austin, TX). Purified RNA samples were sent to our core facility for conversion to cDNA, biotin-labeled, and hybridized to 27 Affymetrix Human Genome U133 Plus 2.0 âGene Chipsâ each of which contained 54,675 probe set identifiers representing more than ~47,400 transcripts that identify ~38,500 well-characterized genes, and various internal controls (Affymetrix, Santa Clara, CA). Mock-infected cells were compared to cells infected with SARS-CoV or DHOV at each time point.
2010-02-24 | E-GEOD-17400 | biostudies-arrayexpress
Project description:To further identify and understand the molecular and immunological correlates of pathology for SARS-CoV infection, we infected 129/S6/SvEv or B129 mice with the TOR2 strain of SARS-CoV. SARS-CoV was detected in the lung and nasal turbinates of infected mice peaking at 1 day post infection (DPI) in both tissues before decreasing rapidly to levels below detection at 7 DPI and 3 DPI, respectively. Pulmonary lesions in virus-infected animals included bronchiolar, peribronchiolar, and perivascular foci of mild to moderate subacute inflammation. Chronic inflammation included inflammatory macrophages, lymphocytes, and plasma cells. Neutralizing antibodies appeared on 5 DPI (IgM); converting to IgG on 7 DPI. Despite the prevailing notion that SARS-CoV interferes with the induction of interferon (IFN) signaling, mice infected with SARS-CoV in vivo demonstrated significantly increased expression of innate antiviral interferon (IFN) response genes (IRGs) in the lungs during the first week of acute infection. By the end of the second week of infection, coordinated expression of MHC class I / II and antigen presentation genes occurred in correlation with declining viral titres. Collectively, the mouse data suggests that robust IFN-driven innate immune responses and a critical shift from innate to adaptive immune responses is necessary for clearance and recovery from SARS-CoV infection. Keywords: time course
2014-11-30 | GSE19137 | GEO
Project description:Background: Type I interferons (IFNs) are essential to the clearance of viral diseases, in part by initiating upregulation of IFN regulated genes (IRGs). A clear distinction between genes upregulated directly by virus and genes upregulated by secondary IFN production has not been made. Here we investigated the genes regulated by IFN-a2b compared to the genes regulated by SARS-CoV infection in ferrets. Methods: We characterized early host immune responses in peripheral blood and lung necropsies of ferrets injected with IFN-a2b or infected with SARS-CoV/Tor 2 strain, using microarray analysis on the Affymetrix platform. Results: We identified a common IRG signature that was upregulated in both SARS-CoV infected ferrets as well as in ferrets injected with IFN-a2b. We also identified unique patterns of gene expression for leukocyte activation, cell adhesion and complement pathways between IFN-a2b injection and SARS-CoV infection. Conclusions: Our results define the effects of IFN-a2b on the immune system of ferrets highlighting genes regulated by IFN during SARS-CoV infection. We have shown the similarities and differences of top funcional gene groups as well as pathways that play key roles in early immune responses in ferrets in response to IFN-a2b or SARS-CoV. Key words: ferret, gene expression, SARS, interferon. Keywords: time course
2010-12-01 | GSE22581 | GEO
Project description:A recombinant SARS-CoV lacking the envelope (E) protein is attenuated in vivo. Here we report that E protein PDZ-binding motif (PBM), a domain involved in protein-protein interactions, is a major virulence determinant in vivo. Elimination of SARS-CoV E protein PBM by using reverse genetics led to attenuated viruses (SARS-CoV-mutPBM) and to a reduction in the deleterious exacerbate immune response triggered during infection with the parental virus (SARS-CoV-wt). Cellular protein syntenin bound E protein PBM during SARS-CoV infection. Syntenin activates p38 MAPK leading to overexpression of inflammatory cytokines, and we have shown that active p38 MAPK was reduced in lungs of mice infected with SARS-CoVs lacking E protein PBM (SARS-CoV-mutPBM) as compared with the parental virus (SARS-CoV-wt), leading to a decreased expression of inflammatory cytokines and to viral attenuation. Therefore, E protein PBM is a virulence factor that activates pathogenic immune response most likely by using syntenin as a mediator of p38 MAPK induced inflammation. Three biological replicates were independently hybridized (one channel per slide) for each sample type (SARS-CoV-wt, SARS-CoV-mutPBM, Mock). Slides were Sure Print G3 Agilent 8x60K Mouse (G4852A-028005)
2014-10-31 | E-GEOD-52920 | biostudies-arrayexpress
Project description:The SARS-CoV-2 genome encodes a multitude of accessory proteins. Using comparative genomic approaches, an additional accessory protein, ORF3c, has been predicted to be encoded within the ORF3a sgmRNA. Expression of ORF3c during infection has been confirmed independently by ribosome profiling. Despite ORF3c also being present in the 2002-2003 SARS-CoV, its function has remained unexplored. Here we show that ORF3c localises only to mitochondria during infection, where it inhibits innate immunity by restricting IFN-β production, but not NF-κB activation or JAK-STAT signalling downstream of type I IFN stimulation. We find that ORF3c acts after stimulation with cytoplasmic RNA helicases RIG-I or MDA5 or adaptor protein MAVS, but not after TRIF, TBK1 or phospho-IRF3 stimulation. ORF3c co-immunoprecipitates with the antiviral proteins MAVS and PGAM5 and induces MAVS cleavage by caspase-3. Unlike early lineage SARS-CoV-2 strains, delta variant strains lack intact ORF3c and do not cleave MAVS to the same extent. Together, these data provide insight into an uncharacterised mechanism of innate immune evasion by this important human pathogen. We suggest a model whereby ORF3c inhibits PGAM5-induced mitophagy and instead induces apoptosis, accompanied by caspase-3 activation. This repository contains data associated with the SARS-CoV-2 ORF3C SILAC AP-MS portions of this work.
2023-10-08 | PXD037765 | Pride
Project description:The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has had devastating impacts on our global society. Although vaccines and monoclonal antibody countermeasures have reduced the morbidity and mortality associated with SARS-CoV-2 infection, variants with constellations of mutations in the spike gene threaten their efficacy. Therefore, antiviral interventions that are resistant to further virus evolution may be needed. Here, we show IFN-λ protects against SARS-CoV-2 B.1.351 (Beta) and B.1.1529 (Omicron) variants in three strains of conventional and human ACE2 transgenic mice. Prophylaxis or therapy with nasally-delivered IFN-λ2 limited infection of historical or variant (B.1.351 and B.1.1.529) SARS-CoV-2 strains in both the upper and lower respiratory tracts without causing excessive inflammation. In the lung, IFN-λ was produced preferentially in epithelial cells and acted on radio-resistant cells to protect against of SARS-CoV-2 infection. Thus, inhaled IFN-λ may have promise as a treatment for evolving SARS-CoV-2 variants that develop resistance to antibody-based countermeasures.
2022-02-08 | GSE193990 | GEO
Project description:To deal with the broad spectrum of coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that threatens human health, it is essential to develop not only drugs that target viral proteins but also consider drugs that target host proteins/cellular processes to protect them from being hijacked for viral infection and replication. To this end, it has been reported that autophagy is deeply involved in coronavirus infection. In this study, we used airway organoids to screen a chemical library of autophagic modulators to identify compounds that could potentially be used to fight against infections by a broad range of coronaviruses. Among the 80 autophagy-related compounds tested, cycloheximide and thapsigargin reduced SARS-CoV-2 infection efficiency in a dose-dependent manner. Cycloheximide treatment reduced the infection efficiency of not only six SARS-CoV-2 variants but also human coronavirus (HCoV)-229E and HCoV-OC43. Cycloheximide treatment also reversed viral infection-induced innate immune responses. However, even low dose (1 μM) cycloheximide treatment altered the expression profile of ribosomal RNAs, thus side effects such as inhibition of protein synthesis in host cells must be considered. These results suggest that cycloheximide has broad-spectrum anti-coronavirus activity in vitro and warrants further investigation.
2023-03-24 | GSE217099 | GEO