RESUMEN
RNA vaccines elicit protective immunity against SARS-CoV-2, but the use of mRNA as an antiviral immunotherapeutic is unexplored. Here, we investigate the activity of lipidoid nanoparticle (LNP)-formulated mRNA encoding human IFNλ1 (ETH47), which is a critical driver of innate immunity at mucosal surfaces protecting from viral infections. IFNλ1 mRNA administration promotes dose-dependent protein translation, induction of interferon-stimulated genes without relevant signs of unspecific immune stimulation, and dose-dependent inhibition of SARS-CoV-2 replication in vitro. Pulmonary administration of IFNλ1 mRNA in mice results in a potent reduction of virus load, virus-induced body weight loss and significantly increased survival. These data support the development of inhaled administration of IFNλ1 mRNA as a potential prophylactic option for individuals exposed to SARS-CoV-2 or at risk suffering from COVID-19. Based on the broad antiviral activity of IFNλ1 regardless of virus or variant, this approach might also be utilized for other respiratory viral infections or pandemic preparedness.
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The brain is highly sensitive to damage caused by infection and inflammation1,2. Herpes simplex virus 1 (HSV-1) is a neurotropic virus and the cause of herpes simplex encephalitis3. It is unknown whether neuron-specific antiviral factors control virus replication to prevent infection and excessive inflammatory responses, hence protecting the brain. Here we identify TMEFF1 as an HSV-1 restriction factor using genome-wide CRISPR screening. TMEFF1 is expressed specifically in neurons of the central nervous system and is not regulated by type I interferon, the best-known innate antiviral system controlling virus infections. Depletion of TMEFF1 in stem-cell-derived human neurons led to elevated viral replication and neuronal death following HSV-1 infection. TMEFF1 blocked the HSV-1 replication cycle at the level of viral entry through interactions with nectin-1 and non-muscle myosin heavy chains IIA and IIB, which are core proteins in virus-cell binding and virus-cell fusion, respectively4-6. Notably, Tmeff1-/- mice exhibited increased susceptibility to HSV-1 infection in the brain but not in the periphery. Within the brain, elevated viral load was observed specifically in neurons. Our study identifies TMEFF1 as a neuron-specific restriction factor essential for prevention of HSV-1 replication in the central nervous system.
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Factores de Restricción Antivirales , Encéfalo , Herpes Simple , Herpesvirus Humano 1 , Proteínas de la Membrana , Neuronas , Internalización del Virus , Replicación Viral , Animales , Femenino , Humanos , Masculino , Ratones , Factores de Restricción Antivirales/metabolismo , Encéfalo/citología , Encéfalo/metabolismo , Encéfalo/patología , Encéfalo/virología , Muerte Celular , Sistemas CRISPR-Cas/genética , Herpes Simple/inmunología , Herpes Simple/metabolismo , Herpes Simple/virología , Herpesvirus Humano 1/crecimiento & desarrollo , Herpesvirus Humano 1/inmunología , Herpesvirus Humano 1/fisiología , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Neuronas/virología , Neuronas/metabolismo , Carga Viral , Nectinas/metabolismo , Miosina Tipo IIA no Muscular/metabolismo , Miosina Tipo IIB no Muscular/metabolismo , Interferón Tipo I , Enfermedades Neuroinflamatorias/inmunología , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/patología , Enfermedades Neuroinflamatorias/prevención & control , Enfermedades Neuroinflamatorias/virologíaRESUMEN
Pattern recognition receptors (PRRs) induce host defense but can also induce exacerbated inflammatory responses. This raises the question of whether other mechanisms are also involved in early host defense. Using transcriptome analysis of disrupted transcripts in herpes simplex virus (HSV)-infected cells, we find that HSV infection disrupts the hypoxia-inducible factor (HIF) transcription network in neurons and epithelial cells. Importantly, HIF activation leads to control of HSV replication. Mechanistically, HIF activation induces autophagy, which is essential for antiviral activity. HSV-2 infection in vivo leads to hypoxia in CNS neurons, and mice with neuron-specific HIF1/2α deficiency exhibit elevated viral load and augmented PRR signaling and inflammatory gene expression in the CNS after HSV-2 infection. Data from human stem cell-derived neuron and microglia cultures show that HIF also exerts antiviral and inflammation-restricting activity in human CNS cells. Collectively, the HIF transcription factor system senses virus-induced hypoxic stress to induce cell-intrinsic antiviral responses and limit inflammation.
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Encefalitis , Herpes Simple , Humanos , Animales , Ratones , Inflamación , Neuronas , Hipoxia , Antivirales/farmacologíaRESUMEN
Immunological control of viral infections in the brain exerts immediate protection and also long-term maintenance of brain integrity. Microglia are important for antiviral defense in the brain. Here, we report that herpes simplex virus type 1 (HSV1) infection of human induced pluripotent stem cell (hiPSC)-derived microglia down-regulates expression of genes in the TREM2 pathway. TREM2 was found to be important for virus-induced IFNB induction through the DNA-sensing cGAS-STING pathway in microglia and for phagocytosis of HSV1-infected neurons. Consequently, TREM2 depletion increased susceptibility to HSV1 infection in human microglia-neuron cocultures and in the mouse brain. TREM2 augmented STING signaling and activation of downstream targets TBK1 and IRF3. Thus, TREM2 is important for the antiviral immune response in microglia. Since TREM2 loss-of-function mutations and HSV1 serological status are both linked to Alzheimer's disease, this work poses the question whether genetic or virus-induced alterations of TREM2 activity predispose to post-infection neurological pathologies.
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Herpes Simple , Herpesvirus Humano 1 , Células Madre Pluripotentes Inducidas , Microglía , Animales , Humanos , Ratones , Encéfalo , Herpes Simple/inmunología , Herpes Simple/virología , Herpesvirus Humano 1/fisiología , Glicoproteínas de Membrana/metabolismo , Receptores Inmunológicos/metabolismoRESUMEN
Neurotropic viruses, including herpes simplex virus (HSV) types 1 and 2, have the capacity to infect neurons and can cause severe diseases. This is associated with neuronal cell death, which may contribute to morbidity or even mortality if the infection is not controlled. However, the mechanistic details of HSV-induced neuronal cell death remain enigmatic. Here, we report that lytic HSV-2 infection of human neuron-like SH-SY5Y cells and primary human and murine brain cells leads to cell death mediated by gasdermin E (GSDME). HSV-2-induced GSDME-mediated cell death occurs downstream of replication-induced endoplasmic reticulum stress driven by inositol-requiring kinase 1α (IRE1α), leading to activation of caspase-2, cleavage of the pro-apoptotic protein BH3-interacting domain death agonist (BID), and mitochondria-dependent activation of caspase-3. Finally, necrotic neurons released alarmins, which activated inflammatory responses in human iPSC-derived microglia. In conclusion, lytic HSV infection in neurons activates an ER stress-driven pathway to execute GSDME-mediated cell death and promote inflammation.
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Critical COVID-19 is characterized by lack of early type I interferon-mediated host defense and subsequent hyper-inflammation in the lungs. Aberrant activation of macrophages and neutrophils has been reported to lead to excessive activation of innate immunological pathways. It has recently been suggested that the DNA-sensing cGAS-STING pathway drives pathology in the SARS-CoV-2-infected lungs, but mechanistic understanding from in vivo models is needed. Here, we tested whether STING is involved in COVID-19-like disease using the K18-hACE2 mouse model. We report that disease development after SARS-CoV-2 infection is unaltered in STING-deficient K18-hACE2 mice. In agreement with this, STING deficiency did not affect control of viral replication or production of interferons and inflammatory cytokines. This was accompanied by comparable profiles of infiltrating immune cells into the lungs of infected mice. These data do not support a role for STING in COVID-19 pathology and calls for further investigation into the pathogenesis of critical COVID-19.
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COVID-19 , Interferón Tipo I , Ratones , Animales , Inmunidad Innata , Transducción de Señal , SARS-CoV-2/metabolismo , Interferón Tipo I/metabolismoRESUMEN
We established a split nanoluciferase complementation assay to rapidly screen for inhibitors that interfere with binding of the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein with its target receptor, angiotensin-converting enzyme 2 (ACE2). After a screen of 1,200 US Food and Drug Administration (FDA)-approved compounds, we identified bifonazole, an imidazole-based antifungal agent, as a competitive inhibitor of RBD-ACE2 binding. Mechanistically, bifonazole binds ACE2 around residue K353, which prevents association with the RBD, affecting entry and replication of spike-pseudotyped viruses as well as native SARS-CoV-2 and its variants of concern (VOCs). Intranasal administration of bifonazole reduces lethality in K18-hACE2 mice challenged with vesicular stomatitis virus (VSV)-spike by 40%, with a similar benefit after live SARS-CoV-2 challenge. Our screen identified an antiviral agent that is effective against SARS-CoV-2 and VOCs such as Omicron that employ the same receptor to infect cells and therefore has high potential to be repurposed to control, treat, or prevent coronavirus disease 2019 (COVID-19).
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Antivirales , Tratamiento Farmacológico de COVID-19 , Imidazoles , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2/antagonistas & inhibidores , Animales , Antivirales/farmacología , Imidazoles/farmacología , Ratones , Unión Proteica , SARS-CoV-2/efectos de los fármacos , Glicoproteína de la Espiga del Coronavirus/química , Estados Unidos , United States Food and Drug AdministrationRESUMEN
Understanding the molecular pathways driving the acute antiviral and inflammatory response to SARS-CoV-2 infection is critical for developing treatments for severe COVID-19. Here, we find decreasing number of circulating plasmacytoid dendritic cells (pDCs) in COVID-19 patients early after symptom onset, correlating with disease severity. pDC depletion is transient and coincides with decreased expression of antiviral type I IFNα and of systemic inflammatory cytokines CXCL10 and IL-6. Using an in vitro stem cell-based human pDC model, we further demonstrate that pDCs, while not supporting SARS-CoV-2 replication, directly sense the virus and in response produce multiple antiviral (interferons: IFNα and IFNλ1) and inflammatory (IL-6, IL-8, CXCL10) cytokines that protect epithelial cells from de novo SARS-CoV-2 infection. Via targeted deletion of virus-recognition innate immune pathways, we identify TLR7-MyD88 signaling as crucial for production of antiviral interferons (IFNs), whereas Toll-like receptor (TLR)2 is responsible for the inflammatory IL-6 response. We further show that SARS-CoV-2 engages the receptor neuropilin-1 on pDCs to selectively mitigate the antiviral interferon response, but not the IL-6 response, suggesting neuropilin-1 as potential therapeutic target for stimulation of TLR7-mediated antiviral protection.
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COVID-19 , Células Dendríticas , Receptor Toll-Like 2 , Receptor Toll-Like 7 , COVID-19/inmunología , COVID-19/patología , Citocinas/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/patología , Humanos , Interferón Tipo I/inmunología , Interferón-alfa/inmunología , Interleucina-6/inmunología , Neuropilina-1/inmunología , SARS-CoV-2 , Receptor Toll-Like 2/inmunología , Receptor Toll-Like 7/inmunologíaRESUMEN
Spread of herpes simplex virus 1 (HSV1) from the periphery to the central nervous system (CNS) can lead to extensive infection and pathological inflammation in the brain, causing herpes simplex encephalitis (HSE). It has been shown that microglia, the CNS-resident macrophages, are involved in early sensing of HSV1 and induction of antiviral responses. In addition, infiltration of peripheral immune cells may contribute to the control of viral infection. In this study, we tested the effect of microglia depletion in a mouse model of HSE. Increased viral titers and increased disease severity were observed in microglia-depleted mice. The effect of microglia depletion was more pronounced in wild-type than in cGas-/- mice, revealing that this immune sensor contributes to the antiviral activity of microglia. Importantly, microglia depletion led to reduced production of type I interferon (IFN), proinflammatory cytokines, and chemokines at early time points after viral entry into the CNS. In line with this, in vitro experiments on murine primary CNS cells demonstrated microglial presence to be essential for IFN RNA induction, and control of HSV1 replication. However, the effect of microglia depletion on the expression of IFNs, and inflammatory cytokines was restricted to the early time point of HSV1 entry into the CNS. There was no major alteration of infiltration of CD45-positive cells in microglia-depleted mice. Collectively, our data demonstrate a key role for microglia in controlling HSV1 replication early after viral entry into the CNS and highlight the importance of a prompt antiviral innate response to reduce the risk of HSE development. IMPORTANCE One of the most devastating and acute neurological conditions is encephalitis, i.e., inflammation of brain tissue. Herpes simplex virus 1 (HSV1) is a highly prevalent pathogen in humans, and the most frequent cause of viral sporadic encephalitis called herpes simplex encephalitis (HSE). HSV1 can infect peripheral neurons and reach the central nervous system (CNS) of humans, where it can be detected by brain resident cells and infiltrating immune cells, leading to protective and damaging immune responses. In this study, we investigated the effects of microglia depletion, the main brain-resident immune cell type. For this purpose, we used a mouse model of HSE. We found that viral levels increased, and disease symptoms worsened in microglia-depleted mice. In addition, mice lacking a major sensor of viral DNA, cGAS, manifested a more pronounced disease than wild-type mice, highlighting the importance of this immune sensor in the activity of microglia. Microglia depletion led to reduced production of many known antiviral factors, most notably type I interferon (IFN). The importance of microglia in the early control of HSV1 spread and the generation of antiviral responses is further demonstrated by experiments on murine mixed glial cell cultures. Interestingly, mice with microglia depletion exhibited an unaltered activation of antiviral responses and recruitment of immune cells from the periphery at later time points of infection, but this did not prevent the development of the disease. Overall, the data highlight the importance of rapid activation of the host defense, with microglia playing a critical role in controlling HSV1 infection, which eventually prevents damage to neurons and brain tissue.
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Encefalitis por Herpes Simple , Herpesvirus Humano 1 , Inmunidad , Interferón Tipo I , Microglía , Internalización del Virus , Animales , Encéfalo/inmunología , Encéfalo/virología , Citocinas/inmunología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Encefalitis por Herpes Simple/inmunología , Encefalitis por Herpes Simple/fisiopatología , Herpesvirus Humano 1/metabolismo , Inmunidad/inmunología , Inflamación/patología , Interferón Tipo I/metabolismo , Ratones , Ratones Endogámicos C57BL , Microglía/inmunología , Microglía/virología , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismoRESUMEN
Concerted alteration of immune and metabolic homeostasis underlies several inflammation-related pathologies, ranging from metabolic syndrome to infectious diseases. Here, we explored the coordination of nucleic acid-dependent inflammatory responses and metabolic homeostasis. We reveal that the STING (stimulator of interferon genes) protein regulates metabolic homeostasis through inhibition of the fatty acid desaturase 2 (FADS2) rate-limiting enzyme in polyunsaturated fatty acid (PUFA) desaturation. STING ablation and agonist-mediated degradation increased FADS2-associated desaturase activity and led to accumulation of PUFA derivatives that drive thermogenesis. STING agonists directly activated FADS2-dependent desaturation, promoting metabolic alterations. PUFAs in turn inhibited STING, thereby regulating antiviral responses and contributing to resolving STING-associated inflammation. Thus, we have unveiled a negative regulatory feedback loop between STING and FADS2 that fine-tunes inflammatory responses. Our results highlight the role of metabolic alterations in human pathologies associated with aberrant STING activation and STING-targeting therapies.
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Ácido Graso Desaturasas , Síndrome Metabólico , Ácido Graso Desaturasas/genética , Ácido Graso Desaturasas/metabolismo , Ácidos Grasos Insaturados/metabolismo , Humanos , Inflamación , Metabolismo de los LípidosRESUMEN
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created an urgent need for new technologies to treat COVID-19. Here we report a 2'-fluoro protected RNA aptamer that binds with high affinity to the receptor binding domain (RBD) of SARS-CoV-2 spike protein, thereby preventing its interaction with the host receptor ACE2. A trimerized version of the RNA aptamer matching the three RBDs in each spike complex enhances binding affinity down to the low picomolar range. Binding mode and specificity for the aptamer-spike interaction is supported by biolayer interferometry, single-molecule fluorescence microscopy, and flow-induced dispersion analysis in vitro. Cell culture experiments using virus-like particles and live SARS-CoV-2 show that the aptamer and, to a larger extent, the trimeric aptamer can efficiently block viral infection at low concentration. Finally, the aptamer maintains its high binding affinity to spike from other circulating SARS-CoV-2 strains, suggesting that it could find widespread use for the detection and treatment of SARS-CoV-2 and emerging variants.
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Aptámeros de Nucleótidos/farmacología , SARS-CoV-2/efectos de los fármacos , Internalización del Virus/efectos de los fármacos , Enzima Convertidora de Angiotensina 2/metabolismo , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/metabolismo , Humanos , Mutación , Pruebas de Neutralización , Conformación de Ácido Nucleico , Unión Proteica/efectos de los fármacos , Dominios y Motivos de Interacción de Proteínas , SARS-CoV-2/fisiología , Técnica SELEX de Producción de Aptámeros , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismoRESUMEN
The alpha/B.1.1.7 SARS-CoV-2 lineage emerged in autumn 2020 in the United Kingdom and transmitted rapidly until winter 2021 when it was responsible for most new COVID-19 cases in many European countries. The incidence domination was likely due to a fitness advantage that could be driven by the receptor-binding domain (RBD) residue change (N501Y), which also emerged independently in other variants of concern such as the beta/B.1.351 and gamma/P.1 strains. Here, we present a functional characterization of the alpha/B.1.1.7 variant and show an eightfold affinity increase towards human angiotensin-converting enzyme-2 (ACE-2). In accordance with this, transgenic hACE2 mice showed a faster disease progression and severity after infection with a low dose of B.1.1.7, compared to an early 2020 SARS-CoV-2 isolate. When challenged with sera from convalescent individuals or anti-RBD monoclonal antibodies, the N501Y variant showed a minor, but significant elevated evasion potential of ACE-2/RBD antibody neutralization. The data suggest that the single asparagine to tyrosine substitution remarkable rise in affinity may be responsible for the higher transmission rate and severity of the B.1.1.7 variant.
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Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19/virología , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo , Enzima Convertidora de Angiotensina 2/inmunología , Animales , Anticuerpos Monoclonales/metabolismo , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , COVID-19/genética , COVID-19/metabolismo , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Ratones , Mutación Missense , Unión Proteica , SARS-CoV-2/genética , SARS-CoV-2/inmunología , Índice de Severidad de la Enfermedad , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Reino UnidoRESUMEN
Viral infections during pregnancy are a considerable cause of adverse outcomes and birth defects, and the underlying mechanisms are poorly understood. Among those, cytomegalovirus (CMV) infection stands out as the most common intrauterine infection in humans, putatively causing early pregnancy loss. We employed murine CMV as a model to study the consequences of viral infection on pregnancy outcome and fertility maintenance. Even though pregnant mice successfully controlled CMV infection, we observed highly selective, strong infection of corpus luteum (CL) cells in their ovaries. High infection densities indicated complete failure of immune control in CL cells, resulting in progesterone insufficiency and pregnancy loss. An abundance of gap junctions, absence of vasculature, strong type I interferon (IFN) responses, and interaction of innate immune cells fully protected the ovarian follicles from viral infection. Our work provides fundamental insights into the effect of CMV infection on pregnancy loss and mechanisms protecting fertility.
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Cuerpo Lúteo/inmunología , Infecciones por Citomegalovirus/inmunología , Fertilidad/inmunología , Inmunidad Innata/inmunología , Animales , Cuerpo Lúteo/virología , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/virología , Femenino , Uniones Comunicantes/inmunología , Interferón Tipo I/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Embarazo , Progesterona/inmunologíaRESUMEN
The rapid development of a SARS-CoV-2 vaccine is a global priority. Here, we develop two capsid-like particle (CLP)-based vaccines displaying the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. RBD antigens are displayed on AP205 CLPs through a split-protein Tag/Catcher, ensuring unidirectional and high-density display of RBD. Both soluble recombinant RBD and RBD displayed on CLPs bind the ACE2 receptor with nanomolar affinity. Mice are vaccinated with soluble RBD or CLP-displayed RBD, formulated in Squalene-Water-Emulsion. The RBD-CLP vaccines induce higher levels of serum anti-spike antibodies than the soluble RBD vaccines. Remarkably, one injection with our lead RBD-CLP vaccine in mice elicits virus neutralization antibody titers comparable to those found in patients that had recovered from COVID-19. Following booster vaccinations, the virus neutralization titers exceed those measured after natural infection, at serum dilutions above 1:10,000. Thus, the RBD-CLP vaccine is a highly promising candidate for preventing COVID-19.
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Anticuerpos Neutralizantes/inmunología , Vacunas contra la COVID-19/inmunología , Cápside/inmunología , Unión Proteica/inmunología , SARS-CoV-2/inmunología , Enzima Convertidora de Angiotensina 2 , Animales , Anticuerpos Antivirales/inmunología , COVID-19/prevención & control , Femenino , Humanos , Inmunogenicidad Vacunal , Cinética , Ratones , Ratones Endogámicos BALB C , Unión Proteica/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Pruebas Serológicas , Glicoproteína de la Espiga del Coronavirus/inmunologíaRESUMEN
Protection of the brain from viral infections involves the type I IFN (IFN-I) system, defects in which render humans susceptible to herpes simplex encephalitis (HSE). However, excessive cerebral IFN-I levels lead to pathologies, suggesting the need for tight regulation of responses. Based on data from mouse models, human HSE cases, and primary cell culture systems, we showed that microglia and other immune cells undergo apoptosis in the HSV-1-infected brain through a mechanism dependent on the cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) pathway, but independent of IFN-I. HSV-1 infection of microglia induced cGAS-dependent apoptosis at high viral doses, whereas lower viral doses led to IFN-I responses. Importantly, inhibition of caspase activity prevented microglial cell death and augmented IFN-I responses. Accordingly, HSV-1-infected organotypic brain slices or mice treated with a caspase inhibitor exhibited lower viral load and an improved infection outcome. Collectively, we identify an activation-induced apoptosis program in brain immune cells that downmodulates local immune responses.
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Encéfalo/inmunología , Herpes Simple/inmunología , Herpesvirus Humano 1/inmunología , Interferón Tipo I/inmunología , Proteínas de la Membrana/inmunología , Nucleotidiltransferasas/inmunología , Animales , Apoptosis/genética , Apoptosis/inmunología , Encéfalo/virología , Herpes Simple/genética , Humanos , Interferón Tipo I/genética , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Microglía/inmunología , Microglía/virología , Nucleotidiltransferasas/genéticaRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMEN
Antiviral strategies to inhibit Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) and the pathogenic consequences of COVID-19 are urgently required. Here, we demonstrate that the NRF2 antioxidant gene expression pathway is suppressed in biopsies obtained from COVID-19 patients. Further, we uncover that NRF2 agonists 4-octyl-itaconate (4-OI) and the clinically approved dimethyl fumarate (DMF) induce a cellular antiviral program that potently inhibits replication of SARS-CoV2 across cell lines. The inhibitory effect of 4-OI and DMF extends to the replication of several other pathogenic viruses including Herpes Simplex Virus-1 and-2, Vaccinia virus, and Zika virus through a type I interferon (IFN)-independent mechanism. In addition, 4-OI and DMF limit host inflammatory responses to SARS-CoV2 infection associated with airway COVID-19 pathology. In conclusion, NRF2 agonists 4-OI and DMF induce a distinct IFN-independent antiviral program that is broadly effective in limiting virus replication and in suppressing the pro-inflammatory responses of human pathogenic viruses, including SARS-CoV2.
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Antiinflamatorios/farmacología , Antivirales/farmacología , Betacoronavirus/efectos de los fármacos , Infecciones por Coronavirus/tratamiento farmacológico , Dimetilfumarato/agonistas , Factor 2 Relacionado con NF-E2/metabolismo , Neumonía Viral/tratamiento farmacológico , Succinatos/agonistas , Adulto , Antioxidantes/farmacología , Betacoronavirus/metabolismo , COVID-19 , Infecciones por Coronavirus/virología , Dimetilfumarato/farmacología , Femenino , Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Interferón Tipo I , Pulmón/patología , Masculino , Factor 2 Relacionado con NF-E2/genética , Pandemias , Neumonía Viral/virología , SARS-CoV-2 , Transducción de Señal/efectos de los fármacos , Succinatos/farmacología , Replicación Viral/efectos de los fármacosRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMEN
STING is essential for control of infections and for tumor immunosurveillance, but it can also drive pathological inflammation. STING resides on the endoplasmic reticulum (ER) and traffics following stimulation to the ERGIC/Golgi, where signaling occurs. Although STING ER exit is the rate-limiting step in STING signaling, the mechanism that drives this process is not understood. Here we identify STEEP as a positive regulator of STING signaling. STEEP was associated with STING and promoted trafficking from the ER. This was mediated through stimulation of phosphatidylinositol-3-phosphate (PtdIns(3)P) production and ER membrane curvature formation, thus inducing COPII-mediated ER-to-Golgi trafficking of STING. Depletion of STEEP impaired STING-driven gene expression in response to virus infection in brain tissue and in cells from patients with STING-associated diseases. Interestingly, STING gain-of-function mutants from patients interacted strongly with STEEP, leading to increased ER PtdIns(3)P levels and membrane curvature. Thus, STEEP enables STING signaling by promoting ER exit.
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Retículo Endoplásmico/metabolismo , Regulación de la Expresión Génica/fisiología , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Transducción de Señal/fisiología , Animales , Retículo Endoplásmico/inmunología , Humanos , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/metabolismo , Proteínas de la Membrana/inmunología , Ratones , Proteínas del Tejido Nervioso/inmunología , Proteínas Nucleares , Transporte de Proteínas/fisiologíaRESUMEN
Herpes simplex virus (HSV) is the main cause of viral encephalitis in the Western world, and the type I interferon (IFN) system is important for antiviral control in the brain. Here, we have compared Ifnb induction in mixed murine brain cell cultures by a panel of HSV1 mutants, each devoid of one mechanism to counteract the IFN-stimulating cGAS-STING pathway. We found that a mutant lacking the deubiquitinase (DUB) activity of the VP1-2 protein induced particularly strong expression of Ifnb and IFN-stimulated genes. HSV1 ΔDUB also induced elevated IFN expression in murine and human microglia and exhibited reduced viral replication in the brain. This was associated with increased ubiquitination of STING and elevated phosphorylation of STING, TBK1, and IRF3. VP1-2 associated directly with STING, leading to its deubiquitination. Recruitment of VP1-2 to STING was dependent on K150 of STING, which was ubiquitinated by TRIM32. Thus, the DUB activity of HSV1 VP1-2 is a major viral immune-evasion mechanism in the brain.