SARS-CoV-2 Diverges from Other Betacoronaviruses in Only Partially Activating the IRE1α/XBP1 Endoplasmic Reticulum Stress Pathway in Human Lung-Derived Cells

mBio, Journal Year: 2022, Volume and Issue: 13(5)

Published: Sept. 20, 2022

SARS-CoV-2 is the third lethal respiratory coronavirus, after MERS-CoV and SARS-CoV, to emerge this century, causing millions of deaths worldwide. Other common coronaviruses such as HCoV-OC43 cause less severe disease.

Language: Английский

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Betacoronaviruses Differentially Activate the Integrated Stress Response to Optimize Viral Replication in Lung-Derived Cell Lines

Viruses, Journal Year: 2025, Volume and Issue: 17(1), P. 120 - 120

Published: Jan. 16, 2025

The betacoronavirus genus contains five of the seven human coronaviruses, making it a particularly critical area research to prepare for future viral emergence. We utilized three betacoronaviruses, one from each subgenus—HCoV-OC43 (embecovirus), SARS-CoV-2 (sarbecovirus), and MERS-CoV (merbecovirus)—, study interactions with PKR-like ER kinase (PERK) pathway integrated stress response (ISR)/unfolded protein (UPR). PERK becomes activated by an abundance unfolded proteins within endoplasmic reticulum (ER), leading phosphorylation eIF2α translational attenuation. demonstrate that MERS-CoV, HCoV-OC43, all activate induce responses downstream p-eIF2α, while only induces detectable p-eIF2α during infection. Using small molecule inhibitor dephosphorylation, we provide evidence HCoV-OC43 maximize replication through dephosphorylation. Interestingly, genetic ablation growth arrest DNA damage-inducible (GADD34) expression, inducible phosphatase 1 (PP1)-interacting partner targeting did not significantly alter or replication, siRNA knockdown constitutive PP1 partner, repressor (CReP), dramatically reduced replication. Combining GADD34 knockout CReP had maximum impact on was unaffected. Overall, conclude dephosphorylation is efficient production SARS-CoV-2, however, appears be insensitive and, infection, may even downregulate limit host translation.

Language: Английский

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A guanidine-based coronavirus replication inhibitor which targets the nsp15 endoribonuclease and selects for interferon-susceptible mutant viruses

PLoS Pathogens, Journal Year: 2025, Volume and Issue: 21(2), P. e1012571 - e1012571

Published: Feb. 11, 2025

The approval of COVID-19 vaccines and antiviral drugs has been crucial to end the global health crisis caused by SARS-CoV-2. However, prepare for future outbreaks from drug-resistant variants novel zoonotic coronaviruses (CoVs), additional therapeutics with a distinct mechanism are needed. Here, we report guanidine-substituted diphenylurea compound that suppresses CoV replication interfering uridine-specific endoribonuclease (EndoU) activity viral non-structural protein-15 (nsp15). This compound, designated EPB-113, exhibits strong selective cell culture against human coronavirus 229E (HCoV-229E) also Viruses, selected under EPB-113 pressure, carried resistance sites at or near catalytic His250 residue nsp15-EndoU domain. Although best-known function EndoU is avoid induction type I interferon (IFN-I) lowering levels dsRNA, was found mainly act via an IFN-independent mechanism, situated during RNA synthesis. Using combination biophysical enzymatic assays recombinant nsp15 proteins HCoV-229E SARS-CoV-2, discovered enhances cleavage hexameric nsp15, while reducing its thermal stability. explains why virus escapes acquiring site mutations which impair binding abolish activity. Since EPB-113-resistant mutant viruses induce high IFN-I effectors, they proved unable replicate in macrophages were readily outcompeted wild-type upon co-infection fibroblast cells. Our findings suggest targeting can be achieved molecule induces conformational change this protein, resulting higher impairment Based on appealing profile conclude challenging but highly relevant drug target.

Language: Английский

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Coronavirus endoribonuclease antagonizes ZBP1-mediated necroptosis and delays multiple cell death pathways

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(10)

Published: March 4, 2025

Identifying conserved mechanisms used by viruses to delay host innate responses can reveal potential targets for antiviral therapeutics. Here, we investigated coronavirus nonstructural protein 15 (nsp15), which encodes a highly endoribonuclease (EndoU). EndoU functions as an immune antagonist limiting the accumulation of viral replication intermediates that would otherwise be sensed host. Despite being promising target, it has been difficult develop small-molecule inhibitors target active site. We generated nsp15 mutants coronaviruses severe acute respiratory syndrome 2 (SARS-CoV-2) and mouse hepatitis virus (MHV)-A59 identified residues within amino-terminal domain are required activity. Loss activity caused activation sensors, limited in interferon-responsive cells attenuated disease MHV-infected mice. Using transcriptional profiling, found MHV mutant upregulate multiple including Z-form nucleic acid-binding 1 (ZBP1). induced early, robust ZBP1-mediated necroptosis. also ZBP1-independent apoptosis pyroptosis pathways, causing cell death limits pathogenesis. Overall, document importance function. highlight nsp15/EndoU evading delaying death, promoting

Language: Английский

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Variable DPP4 expression in multiciliated cells of the human nasal epithelium as a determinant for MERS-CoV tropism

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(11)

Published: March 6, 2025

Transmissibility of respiratory viruses is a complex viral trait that intricately linked to tropism. Several highly transmissible viruses, including severe acute syndrome coronavirus 2 and Influenza specifically target multiciliated cells in the upper tract facilitate efficient human-to-human transmission. In contrast, zoonotic Middle East (MERS-CoV) generally transmits poorly between humans, which largely attributed absence its receptor dipeptidyl peptidase 4 (DPP4) tract. At same time, MERS-CoV epidemiology characterized by occasional superspreading events, suggesting some individuals can disseminate this virus effectively. Here, we utilized well-differentiated human pulmonary nasal airway organoid-derived cultures further delineate tropism MERS-CoV. We find replicated high titers both cultures. Using single-cell messenger-RNA sequencing, immunofluorescence, immunohistochemistry, show preferentially targeted cells, leading loss ciliary coverage. cellular was dependent on differentiation cultures, replication efficiency varied considerably donors. Similarly, variable focal expression DPP4 revealed nose tissues. This study indicates may vary due differences expression, providing an explanation for unpredictable transmission pattern

Language: Английский

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Global surveillance and countermeasures for ACE2-using MERS-related coronaviruses with spillover risk

Cell, Journal Year: 2025, Volume and Issue: 188(6), P. 1465 - 1468

Published: March 1, 2025

Language: Английский

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Contribution to pathogenesis of accessory proteins of deadly human coronaviruses

Frontiers in Cellular and Infection Microbiology, Journal Year: 2023, Volume and Issue: 13

Published: May 1, 2023

Coronaviruses (CoVs) are enveloped and positive-stranded RNA viruses with a large genome (∼ 30kb). CoVs include essential genes, such as the replicase four genes coding for structural proteins (S, M, N E), encoding accessory proteins, which variable in number, sequence function among different CoVs. Accessory non-essential virus replication, but frequently involved virus-host interactions associated virulence. The scientific literature on CoV includes information analyzing effect of deleting or mutating context viral infection, requires engineering genomes using reverse genetics systems. However, considerable number publications analyze gene by overexpressing protein absence other proteins. This ectopic expression provides relevant information, although does not acknowledge complex interplay during infection. A critical review may be helpful to interpret apparent discrepancies conclusions obtained experimental approaches. summarizes current knowledge human an emphasis their contribution pathogenesis. help search antiviral drugs vaccine development, still needed some highly pathogenic

Language: Английский

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PARP12 is required to repress the replication of a Mac1 mutant coronavirus in a cell- and tissue-specific manner

Journal of Virology, Journal Year: 2023, Volume and Issue: 97(9)

Published: Sept. 11, 2023

ABSTRACT ADP-ribosyltransferases (ARTs) mediate the transfer of ADP-ribose from NAD + to protein or nucleic acid substrates. This modification can be removed by several different types proteins, including macrodomains. Several ARTs, also known as PARPs, are stimulated interferon indicating ADP-ribosylation is an important aspect innate immune response. All coronaviruses (CoVs) encode for a highly conserved macrodomain (Mac1) that critical CoVs replicate and cause disease, effectively control coronavirus infection. Our siRNA screen indicated PARP12 might inhibit replication murine hepatitis virus (MHV) Mac1 mutant in bone-marrow-derived macrophages (BMDMs). To conclusively demonstrate key mediator antiviral response both cell culture vivo , we produced −/− mice tested ability MHV A59 (hepatotropic/neurotropic) JHM (neurotropic) viruses disease these mice. Notably, absence PARP12, was increased BMDMs In addition, liver pathology A59-infected However, knockout did not restore WT levels all tissue significantly increase lethality viruses. These results while inhibits infection, additional PARPs factors must contribute extreme attenuation this IMPORTANCE Over last decade, importance (ARTs), has gained significance were shown either restrict impact responses. there few studies showing ART-mediated inhibition pathogenesis animal models. We found CoV required prevent culture. Using mice, interferon-stimulated ART, repress demonstrating represses replication. deletion fully rescue pathogenesis, multiple function counter

Language: Английский

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SARS-CoV-2 nsp15 endoribonuclease antagonizes dsRNA-induced antiviral signaling

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Nov. 15, 2023

ABSTRACT Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of deaths since emerging 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 mutant recombinant (nsp15 mut ) expressing catalytically inactive nsp15. Infection with led to increased the IFN signaling PKR pathways lung-derived epithelial cell lines primary nasal air-liquid interface (ALI) cultures well significant attenuation ALI compared wild-type (WT) virus. This defect was rescued when inhibited Janus activated (JAK) inhibitor ruxolitinib. Finally, assess function context minimal (MERS-CoV) or moderate (SARS-CoV-2) innate induction, previously described MERS-CoV mutants. Inactivation had more dramatic impact on than both Calu3 cells suggesting that can better tolerate responses. Taken together, potent dsRNA-induced response its necessary viral culture. SIGNIFICANCE causes spectrum disease ranging from asymptomatic severe pneumonia death. responses infection have been associated clinical severity, robust early epithelium reported be protective. Thus, elucidating mechanisms through which induces antagonizes host understanding encode various antagonists, contains an domain. We demonstrate EndoU antagonist, providing further evidence role antagonizing activation, thereby optimizing replication.

Language: Английский

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Bile acids and bile acid activated receptors in the treatment of Covid-19

Biochemical Pharmacology, Journal Year: 2023, Volume and Issue: 228, P. 115983 - 115983

Published: Dec. 9, 2023

Since its first outbreak in 2020, the pandemic caused by Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) has death of almost 7 million people worldwide. Vaccines have been fundamental disease prevention and to reduce severity especially patients with comorbidities. Nevertheless, treatment COVID-19 proven difficult several approaches failed prevent onset or progression, particularly Interrogation drug data bases widely used since beginning repurpose existing drugs/natural substances for prevention/treatment COVID-19. Steroids, including bile acids such as ursodeoxycholic acid (UDCA) chenodeoxycholic (CDCA) shown be promising their potential modulating SARS-CoV-2/host interaction. Bile effective preventing binding spike protein Angiotensin Converting Enzyme II (ACE2), thus virus uptake host cells inhibiting replication, well indirectly immune response. Additionally, two main activated receptors, GPBAR1 FXR, expression ACE2, suggesting an indirect role these receptors regulating SARS-CoV-2 infectiveness In this review we examined how anti-COVID-19 therapies biochemical mechanisms translate into clinical efficacy.

Language: Английский

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