MERS-CoV-nsp5 expression in human epithelial BEAS 2b cells attenuates type I interferon production by inhibiting IRF3 nuclear translocation DOI Creative Commons
Yamei Zhang, Shubhangi Kandwal, Darren Fayne

et al.

Cellular and Molecular Life Sciences, Journal Year: 2024, Volume and Issue: 81(1)

Published: Oct. 12, 2024

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is an enveloped, positive-sense RNA virus that emerged in 2012, causing sporadic cases and localized outbreaks of severe respiratory illness with high fatality rates. A characteristic feature the immune response to MERS-CoV infection low type I IFN induction, despite its importance viral clearance. The non-structural proteins (nsps) other coronaviruses have been shown block production. However, role nsp5 from induction human cells unclear. In this study, we elucidated MERS-CoV-nsp5, main protease, modulating host's antiviral responses bronchial epithelial BEAS 2b cells. We found overexpression MERS-CoV-nsp5 had a dose-dependent inhibitory effect on IFN-β promoter activation cytokine production induced by HMW-poly(I:C). It also suppressed triggered key components RIG-I-like receptor (RLR) pathway, including RIG-I, MAVS, IKK-ε IRF3. Moreover, did not impair expression or phosphorylation IRF3, but nuclear translocation Further investigation revealed specifically interacted Using docking molecular dynamic (MD) simulations, amino acids KPNA4 may participate protein-protein interactions. Additionally, uncovered protein conformations mask localization signal (NLS) regions IRF3 when interacting suggesting mechanism which blocks translocation. Of note, was restored after administration protease inhibitors targeting nsp5, indicating suppression dependent enzyme activity nsp5. Collectively, our findings elucidate disrupts innate immunity thus provides insights into pathogenesis.

Language: Английский

SARS-CoV-2 nsp15 endoribonuclease antagonizes dsRNA-induced antiviral signaling DOI Creative Commons
Clayton J. Otter, Nicole Bracci, Nicholas A. Parenti

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(15)

Published: April 3, 2024

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of deaths since its emergence in 2019. Innate immune antagonism by lethal CoVs such as SARS-CoV-2 is crucial for optimal replication and pathogenesis. The conserved nonstructural protein 15 (nsp15) endoribonuclease (EndoU) limits activation double-stranded (ds)RNA-induced pathways, including interferon (IFN) signaling, kinase R (PKR), oligoadenylate synthetase/ribonuclease L (OAS/RNase L) during diverse CoV infections murine Middle East (MERS)-CoV. To determine how nsp15 functions infection, we constructed a recombinant (nsp15

Language: Английский

Citations

21
Infection of primary nasal epithelial cells differentiates among lethal and seasonal human coronaviruses DOI Creative Commons
Clayton J. Otter, Alejandra Fausto, Li Tan

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(15)

Published: April 6, 2023

The nasal epithelium is the initial entry portal and primary barrier to infection by all human coronaviruses (HCoVs). We utilize epithelial cells grown at air-liquid interface, which recapitulate heterogeneous cellular population as well mucociliary clearance functions of in vivo epithelium, compare lethal [Severe acute respiratory syndrome (SARS)-CoV-2 Middle East syndrome-CoV (MERS-CoV)] seasonal (HCoV-NL63 HCoV-229E) HCoVs. All four HCoVs replicate productively cultures, though replication differentially modulated temperature. Infections conducted 33 °C vs. 37 (reflective temperatures upper lower airway, respectively) revealed that both -229E) significantly attenuated °C. In contrast, SARS-CoV-2 MERS-CoV temperatures, enhanced late infection. These also diverge terms cytotoxicity induced following infection, cause disruption, while does not. Treatment cultures with type 2 cytokine IL-13 mimic asthmatic airways impacts HCoV receptor availability replication. DPP4 expression increases treatment, whereas ACE2, used HCoV-NL63, down-regulated. treatment enhances HCoV-229E but reduces reflecting impact on availability. This study highlights diversity among during likely influence downstream outcomes such disease severity transmissibility.

Language: Английский

Citations

40
SARS-CoV-2 Mac1 is required for IFN antagonism and efficient virus replication in cell culture and in mice DOI Creative Commons
Yousef M. Alhammad,

Srivatsan Parthasarathy,

Roshan Ghimire

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(35)

Published: Aug. 22, 2023

Several coronavirus (CoV) encoded proteins are being evaluated as targets for antiviral therapies COVID-19. Included in these drug is the conserved macrodomain, or Mac1, an ADP-ribosylhydrolase and ADP-ribose binding protein a small domain at N terminus of nonstructural 3. Utilizing point mutant recombinant viruses, Mac1 was shown to be critical both murine hepatitis virus (MHV) severe acute respiratory syndrome (SARS)-CoV virulence. However, potential target, it imperative understand how complete deletion impacts replication pathogenesis different CoVs. To this end, we created bacterial artificial chromosomes (BACs) containing deletions (ΔMac1) MHV, MERS-CoV, SARS-CoV-2. While were unable recover infectious from MHV MERS-CoV ΔMac1 BACs, SARS-CoV-2 readily recovered BAC transfection, indicating stark difference requirement between Furthermore, replicated near wild-type levels multiple cell lines susceptible infection. mouse model infection, quickly cleared causing minimal pathology without any morbidity. induced increased interferon (IFN) IFN-stimulated gene expression culture mice, that blocks IFN responses which may contribute its attenuation. infection also led reduction inflammatory monocytes neutrophils. These results demonstrate only minimally replication, unlike but required unique target.

Language: Английский

Citations

39
Recurrent viral capture of cellular phosphodiesterases that antagonize OAS-RNase L DOI Creative Commons
Stephen A. Goldstein, Nels C. Elde

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(5)

Published: Jan. 26, 2024

Phosphodiesterases (PDEs) encoded by viruses are putatively acquired horizontal transfer of cellular PDE ancestor genes. Viral PDEs inhibit the OAS-RNase L antiviral pathway, a key effector component innate immune response. Although function these proteins is well-characterized, origins gene acquisitions less clear. Phylogenetic analysis revealed at least five independent acquisition events ancestral viruses. We found evidence that PDE-encoding genes were horizontally transferred between coronaviruses belonging to different genera. Three clades within Nidovirales : merbecoviruses (MERS-CoV), embecoviruses (HCoV-OC43), and toroviruses encode independently PDEs, clade rodent alphacoronaviruses an embecovirus via recent transfer. Among rotaviruses, rotavirus A was from B G which share common ancestor. Conserved motif suggests link all viral similar among mammalian AKAP7 despite low levels sequence conservation. Additionally, we used reconstruction structural modeling reveal divergence not well-correlated proteins. Specifically, merbecovirus as structurally divergent protein solved structure human they each other. In contrast, comparisons virtually unchanged structures for loss in one, suggesting impactful changes lie outside conserved catalytic sites. These findings highlight complex volatile evolutionary history provide framework facilitate future studies.

Language: Английский

Citations

9
Flipped over U: structural basis for dsRNA cleavage by the SARS-CoV-2 endoribonuclease DOI Creative Commons
Meredith N. Frazier, Isha M. Wilson, J.M. Krahn

et al.

Nucleic Acids Research, Journal Year: 2022, Volume and Issue: 50(14), P. 8290 - 8301

Published: July 8, 2022

Abstract Coronaviruses generate double-stranded (ds) RNA intermediates during viral replication that can activate host immune sensors. To evade activation of the pattern recognition receptor MDA5, coronaviruses employ Nsp15, which is a uridine-specific endoribonuclease. Nsp15 proposed to associate with coronavirus replication-transcription complex within double-membrane vesicles cleave these dsRNA intermediates. How recognizes and processes poorly understood because previous structural studies have been limited small single-stranded (ss) substrates. Here we present cryo-EM structures SARS-CoV-2 bound 52nt dsRNA. We observed hexamer forms platform for engaging across multiple protomers. The structures, along site-directed mutagenesis cleavage assays revealed critical insight into processing. process utilizes base-flipping mechanism properly orient uridine active site cleavage. Our findings show distinctive endoribonuclease both ss- effectively.

Language: Английский

Citations

34
Interferon at the crossroads of SARS-CoV-2 infection and COVID-19 disease DOI Creative Commons
Charles E. Samuel

Journal of Biological Chemistry, Journal Year: 2023, Volume and Issue: 299(8), P. 104960 - 104960

Published: June 24, 2023

A novel coronavirus now known as SARS-CoV-2 emerged in late 2019, possibly following a zoonotic crossover from present bats. This virus was identified the pathogen responsible for severe respiratory disease, disease-19 (COVID-19), which of May 2023, has killed an estimated 6.9 million people globally according to World Health Organization. The interferon (IFN) response, cornerstone antiviral innate immunity, plays key role determining outcome infection by SARS-CoV-2. review considers evidence that leads IFN production; replication is sensitive action; molecular mechanisms antagonizes and how genetic variability human host affects response at level production or action both. Taken together, current understanding suggests deficiency effective important determinant underlying some cases critical COVID-19 disease IFNλ IFNα/β have potential therapeutics treatment infection.

Language: Английский

Citations

21
Coronavirus accessory protein ORF3 biology and its contribution to viral behavior and pathogenesis DOI Creative Commons
Fusheng Si, Shuai Song,

Ruisong Yu

et al.

iScience, Journal Year: 2023, Volume and Issue: 26(4), P. 106280 - 106280

Published: Feb. 28, 2023

Coronavirus porcine epidemic diarrhea virus (PEDV) is classified in the genus Alphacoronavirus, family Coronaviridae that encodes only accessory protein, ORF3 protein. However, how contributes to viral pathogenicity, adaptability, and replication obscure. In this review, we summarize current knowledge identify gaps many aspects of protein PEDV, with emphasis on its unique biological features, including membrane topology, Golgi retention mechanism, potential intrinsic disordered property, functional motifs, glycosylation, codon usage phenotypes related genetic evolution gene expression. addition, propose intriguing questions hope stimulate further studies encourage collaboration among virologists worldwide provide constructive about characteristics functions by which their role clarifying behavior pathogenesis can be possible.

Language: Английский

Citations

18
The Main Protease of Middle East Respiratory Syndrome Coronavirus Induces Cleavage of Mitochondrial Antiviral Signaling Protein to Antagonize the Innate Immune Response DOI Creative Commons
Mariska van Huizen,

Xavier Martinez Vendrell,

Heidi L.M. De Gruyter

et al.

Viruses, Journal Year: 2024, Volume and Issue: 16(2), P. 256 - 256

Published: Feb. 5, 2024

Mitochondrial antiviral signaling protein (MAVS) is a crucial adaptor in the sensing of positive-sense RNA viruses and subsequent induction innate immune response. Coronaviruses have evolved multiple mechanisms to evade this response, amongst others, through their main protease (Mpro), which responsible for proteolytic cleavage largest part viral replicase polyproteins pp1a pp1ab. Additionally, it can cleave cellular substrates, such as factors, dampen Here, we show that MAVS cleaved cells infected with Middle East respiratory syndrome coronavirus (MERS-CoV), but not severe acute 2 (SARS-CoV-2). This was independent negative feedback regulate activation. Furthermore, MERS-CoV Mpro expression induced upon overexpression suppressed activation interferon-β (IFN-β) nuclear factor-κB (NF-κB) We conclude uncovered novel mechanism by downregulates observed among other highly pathogenic coronaviruses.

Language: Английский

Citations

5
Interferon signaling in the nasal epithelium distinguishes among lethal and common cold coronaviruses and mediates viral clearance DOI Creative Commons
Clayton J. Otter, David M. Renner, Alejandra Fausto

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(21)

Published: May 17, 2024

All respiratory viruses establish primary infections in the nasal epithelium, where efficient innate immune induction may prevent dissemination to lower airway and thus minimize pathogenesis. Human coronaviruses (HCoVs) cause a range of pathologies, but host viral determinants disease during common cold versus lethal HCoV are poorly understood. We model initial site infection using epithelial cells cultured at an air-liquid interface (ALI). HCoV-229E, HCoV-NL63, human rhinovirus-16 cold-associated that exhibit unique features this model: early antiviral interferon (IFN) signaling, IFN-mediated clearance, preferential replication temperature (33 °C) which confers muted IFN responses. In contrast, SARS-CoV-2 MERS-CoV encode antagonist proteins clearance cultures. Our study identifies shared among viruses, highlighting responses as predictive outcomes nasally directed IFNs potential therapeutics.

Language: Английский

Citations

5
The coronavirus nsp15 endoribonuclease: A puzzling protein and pertinent antiviral drug target DOI
Benjamin Van Loy, Annelies Stevaert, Lieve Naesens

et al.

Antiviral Research, Journal Year: 2024, Volume and Issue: 228, P. 105921 - 105921

Published: May 31, 2024

Language: Английский

Citations

5