Influenza A virus NS1 effector domain is required for PA-X-mediated host shutoff in infected cells

Journal of Virology, Год журнала: 2024, Номер 98(5)

Опубликована: Апрель 17, 2024

ABSTRACT Many viruses inhibit general host gene expression to limit innate immune responses and gain preferential access the cellular translational apparatus for their protein synthesis. This process is known as shutoff. Influenza A (IAVs) encode two shutoff proteins: nonstructural 1 (NS1) polymerase acidic X (PA-X). NS1 inhibits nuclear pre-messenger RNA maturation export, PA-X an endoribonuclease that preferentially cleaves spliced cytoplasmic messenger RNAs. Emerging evidence suggests in circulating human IAVs co-evolve ensure optimal magnitude of without compromising viral replication relies on cell metabolism. However, functional interplay between remains unexplored. In this study, we sought determine whether function has a direct effect activity by analyzing A549 cells infected with wild-type or mutant effector domain deletion. was done using conventional quantitative reverse transcription chain reaction techniques sequencing nanopore technology. Our previous research molecular mechanisms identified prominent features IAV-infected cells: accumulation poly(A) binding (PABPC1) increase abundance relative cytoplasm. Here demonstrate augments necessary PABPC1 accumulation. By contrast, not dependent either PA-X-mediated accompanied retention transcripts. study demonstrates first time may functionally interact mediating IMPORTANCE Respiratory including influenza virus continue cause annual epidemics high morbidity mortality due limited effectiveness vaccines antiviral drugs. Among strategies evolved evade shutoff—a blockade Disabling being explored live attenuated vaccine development attractive strategy increasing boosting responses. encodes proteins shutoff: We others have characterized some action additive effects these ensuring expression. work, examined discovered required effectively. work significantly advances our understanding identifies new potential targets therapeutic interventions against further informs improved vaccines.

Язык: Английский

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

Viruses, Год журнала: 2025, Номер 17(1), С. 120 - 120

Опубликована: Янв. 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.

Язык: Английский

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Indomethacin inhibits human seasonal coronaviruses at late stages of viral replication in lung cells: effect on virus-induced COX-2 expression

Journal of Virus Eradication, Год журнала: 2024, Номер 10(3), С. 100387 - 100387

Опубликована: Сен. 1, 2024

Coronaviruses (CoV), zoonotic viruses periodically emerging worldwide, represent a constant potential threat to humans. To date, seven human coronaviruses (HCoV) have been identified: HCoV-229E, HCoV-NL63, HCoV-OC43 and HCoV-HKU1, globally circulating in the population (seasonal coronaviruses, sHCoV), three highly-pathogenic SARS-CoV, MERS-CoV SARS-CoV-2. Although sHCoV generally cause only mild respiratory diseases, severe complications may occur specific populations, highlighting need for broad-spectrum anti-coronavirus drugs. Herein we show that indomethacin (INDO), non-steroidal anti-inflammatory drug widely used clinic its potent analgesic properties, effectively inhibits replication of Alpha-coronavirus HCoV-229E Beta-coronavirus lung-derived cells. Indomethacin does not interfere with HCoV binding or entry into target cells, but acts at late stages virus life cycle, inhibiting viral RNA synthesis infectious particles production. INDO action is mediated by blocking cyclooxygenase-1 -2 (COX-1/2) enzymatic activity, antiviral effect appears be cyclooxygenase-independent mimicked COX-1/2 inhibitor aspirin. Interestingly found both seasonal HCoVs markedly (>100 fold) induce expression pro-inflammatory mediator COX-2 lung cells; notably, INDO-treatment was inhibit virus-induced transcriptional level, revealing an additional mechanism prevent COX-2-mediated inflammatory reactions HCoV-infected besides COX activity inhibition. Altogether results indicate indomethacin, possessing properties direct against HCoV, could effective treatment Alpha- infections.

Язык: Английский

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

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Сен. 26, 2024

The betacoronavirus genus contains five of the seven human viruses, 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 interaction 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 in lung derived cell lines. 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 GADD34 expression, inducible phosphatase 1 (PP1)-interacting partner targeting did not significantly alter or replication, siRNA knockdown constitutive PP1 partner, CReP, dramatically reduced replication. Combining growth arrest DNA damage-inducible (GADD34) knockout peripheral membrane-targeted (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.

Язык: Английский

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