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1.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34099577

RESUMO

Coronaviruses are pathogens of pandemic potential. Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of zoonotic infection. More than 70% of MERS-CoV-infected dromedaries are found in East, North, and West Africa, but zoonotic MERS disease is only reported from the Arabian Peninsula. We compared viral replication competence of clade A and B viruses from the Arabian Peninsula with genetically diverse clade C viruses found in East (Egypt, Kenya, and Ethiopia), North (Morocco), and West (Nigeria and Burkina Faso) Africa. Viruses from Africa had lower replication competence in ex vivo cultures of the human lung and in lungs of experimentally infected human-DPP4 (hDPP4) knockin mice. We used lentivirus pseudotypes expressing MERS-CoV spike from Saudi Arabian clade A prototype strain (EMC) or African clade C1.1 viruses and demonstrated that clade C1.1 spike was associated with reduced virus entry into the respiratory epithelial cell line Calu-3. Isogenic EMC viruses with spike protein from EMC or clade C1.1 generated by reverse genetics showed that the clade C1.1 spike was associated with reduced virus replication competence in Calu-3 cells in vitro, in ex vivo human bronchus, and in lungs of hDPP4 knockin mice in vivo. These findings may explain why zoonotic MERS disease has not been reported from Africa so far, despite exposure to and infection with MERS-CoV.


Assuntos
Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Zoonoses/virologia , África , Animais , Arábia , Linhagem Celular , Dipeptidil Peptidase 4/metabolismo , Técnicas de Introdução de Genes , Humanos , Cinética , Coronavírus da Síndrome Respiratória do Oriente Médio/fisiologia , Fenótipo , Filogenia , Glicoproteína da Espícula de Coronavírus/metabolismo , Replicação Viral/fisiologia
2.
Nat Commun ; 12(1): 3431, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103499

RESUMO

The current COVID-19 pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We demonstrate that despite the large size of the viral RNA genome (~30 kb), infectious full-length cDNA is readily assembled in vitro by a circular polymerase extension reaction (CPER) methodology without the need for technically demanding intermediate steps. Overlapping cDNA fragments are generated from viral RNA and assembled together with a linker fragment containing CMV promoter into a circular full-length viral cDNA in a single reaction. Transfection of the circular cDNA into mammalian cells results in the recovery of infectious SARS-CoV-2 virus that exhibits properties comparable to the parental virus in vitro and in vivo. CPER is also used to generate insect-specific Casuarina virus with ~20 kb genome and the human pathogens Ross River virus (Alphavirus) and Norovirus (Calicivirus), with the latter from a clinical sample. Additionally, reporter and mutant viruses are generated and employed to study virus replication and virus-receptor interactions.


Assuntos
Genética Reversa , SARS-CoV-2/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Chlorocebus aethiops , Culicidae/virologia , Furina/metabolismo , Genoma Viral , Células HEK293 , Humanos , Camundongos , Mutação/genética , Células NIH 3T3 , Reação em Cadeia da Polimerase , Células RAW 264.7 , Receptores Virais/metabolismo , Células Vero , Proteínas Virais/química , Replicação Viral
3.
Viruses ; 13(6)2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34064125

RESUMO

To initiate infection, a virus enters a host cell typically via receptor-dependent endocytosis. It then penetrates a subcellular membrane, reaching a destination that supports transcription, translation, and replication of the viral genome. These steps lead to assembly and morphogenesis of the new viral progeny. The mature virus finally exits the host cell to begin the next infection cycle. Strikingly, viruses hijack host molecular chaperones to accomplish these distinct entry steps. Here we highlight how DNA viruses, including polyomavirus and the human papillomavirus, exploit soluble and membrane-associated chaperones to enter a cell, penetrating and escaping an intracellular membrane en route for infection. We also describe the mechanism by which RNA viruses-including flavivirus and coronavirus-co-opt cytosolic and organelle-selective chaperones to promote viral endocytosis, protein biosynthesis, replication, and assembly. These examples underscore the importance of host chaperones during virus infection, potentially revealing novel antiviral strategies to combat virus-induced diseases.


Assuntos
Vírus de DNA/fisiologia , Chaperonas Moleculares/metabolismo , Vírus de RNA/fisiologia , Citosol/metabolismo , Vírus de DNA/metabolismo , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/virologia , Endossomos/metabolismo , Endossomos/virologia , Interações Hospedeiro-Patógeno , Membranas Intracelulares/metabolismo , Vírus de RNA/metabolismo , Internalização do Vírus , Replicação Viral
4.
Viruses ; 13(6)2021 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067381

RESUMO

After more than one year of the COVID-19 pandemic, antiviral treatment options against SARS-CoV-2 are still severely limited. High hopes that had initially been placed on antiviral drugs like remdesivir have so far not been fulfilled. While individual case reports provide striking evidence for the clinical efficacy of remdesivir in the right clinical settings, major trials failed to demonstrate this. Here, we highlight and discuss the key findings of these studies and underlying reasons for their failure. We elaborate on how such shortcomings should be prevented in future clinical trials and pandemics. We suggest in conclusion that any novel antiviral agent that enters human trials should first be tested in a post-exposure setting to provide rapid and solid evidence for its clinical efficacy before initiating further time-consuming and costly clinical trials for more advanced disease. In the COVID-19 pandemic this might have established remdesivir early on as an efficient antiviral agent at a more suitable disease stage which would have saved many lives, in particular in large outbreaks within residential care homes.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , Monofosfato de Adenosina/uso terapêutico , Alanina/uso terapêutico , COVID-19/epidemiologia , Humanos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia , Resultado do Tratamento , Replicação Viral/efeitos dos fármacos
5.
Viruses ; 13(6)2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070524

RESUMO

SARS-CoV-2 emerged in 2019 as a devastating viral pathogen with no available preventative or treatment to control what led to the current global pandemic. The continued spread of the virus and increasing death toll necessitate the development of effective antiviral treatments to combat this virus. To this end, we evaluated a new class of organometallic complexes as potential antivirals. Our findings demonstrate that two pentamethylcyclopentadienyl (Cp*) rhodium piano stool complexes, Cp*Rh(1,3-dicyclohexylimidazol-2-ylidene)Cl2 (complex 2) and Cp*Rh(dipivaloylmethanato)Cl (complex 4), have direct virucidal activity against SARS-CoV-2. Subsequent in vitro testing suggests that complex 4 is the more stable and effective complex and demonstrates that both 2 and 4 have low toxicity in Vero E6 and Calu-3 cells. The results presented here highlight the potential application of organometallic complexes as antivirals and support further investigation into their activity.


Assuntos
Antivirais/farmacologia , Compostos Organometálicos/farmacologia , SARS-CoV-2/efeitos dos fármacos , Animais , Antivirais/química , COVID-19/virologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Compostos Organometálicos/química , SARS-CoV-2/fisiologia , Células Vero , Replicação Viral/efeitos dos fármacos
6.
Nat Commun ; 12(1): 3309, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083527

RESUMO

The ongoing pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), necessitates strategies to identify prophylactic and therapeutic drug candidates for rapid clinical deployment. Here, we describe a screening pipeline for the discovery of efficacious SARS-CoV-2 inhibitors. We screen a best-in-class drug repurposing library, ReFRAME, against two high-throughput, high-content imaging infection assays: one using HeLa cells expressing SARS-CoV-2 receptor ACE2 and the other using lung epithelial Calu-3 cells. From nearly 12,000 compounds, we identify 49 (in HeLa-ACE2) and 41 (in Calu-3) compounds capable of selectively inhibiting SARS-CoV-2 replication. Notably, most screen hits are cell-line specific, likely due to different virus entry mechanisms or host cell-specific sensitivities to modulators. Among these promising hits, the antivirals nelfinavir and the parent of prodrug MK-4482 possess desirable in vitro activity, pharmacokinetic and human safety profiles, and both reduce SARS-CoV-2 replication in an orthogonal human differentiated primary cell model. Furthermore, MK-4482 effectively blocks SARS-CoV-2 infection in a hamster model. Overall, we identify direct-acting antivirals as the most promising compounds for drug repurposing, additional compounds that may have value in combination therapies, and tool compounds for identification of viral host cell targets.


Assuntos
Antivirais/farmacologia , COVID-19/tratamento farmacológico , Reposicionamento de Medicamentos/métodos , Pandemias , SARS-CoV-2 , Animais , COVID-19/prevenção & controle , COVID-19/virologia , Linhagem Celular , Citidina/administração & dosagem , Citidina/análogos & derivados , Citidina/farmacologia , Bases de Dados de Produtos Farmacêuticos , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Células HeLa , Ensaios de Triagem em Larga Escala/métodos , Humanos , Hidroxilaminas/administração & dosagem , Hidroxilaminas/farmacologia , Mesocricetus , Nelfinavir/farmacologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia , Replicação Viral/efeitos dos fármacos
7.
Int J Mol Sci ; 22(11)2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34063964

RESUMO

COVID-19 is a respiratory disease caused by newly discovered severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease at first was identified in the city of Wuhan, China in December 2019. Being a human infectious disease, it causes high fever, cough, breathing problems. In some cases it can be fatal, especially in people with comorbidities like heart or kidney problems and diabetes. The current COVID-19 treatment is based on symptomatic therapy, so finding an appropriate drug against COVID-19 remains an immediate and crucial target for the global scientific community. Two main processes are thought to be responsible for the COVID-19 pathogenesis. In the early stages of infection, disease is determined mainly by virus replication. In the later stages of infection, by an excessive immune/inflammatory response, leading to tissue damage. Therefore, the main treatment options are antiviral and immunomodulatory/anti-inflammatory agents. Many clinical trials have been conducted concerning the use of various drugs in COVID-19 therapy, and many are still ongoing. The majority of trials examine drug reposition (repurposing), which seems to be a good and effective option. Many drugs have been repurposed in COVID-19 therapy including remdesivir, favipiravir, tocilizumab and baricitinib. The aim of this review is to highlight (based on existing and accessible clinical evidence on ongoing trials) the current and available promising drugs for COVID-19 and outline their characteristics.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , Reposicionamento de Medicamentos/métodos , SARS-CoV-2/efeitos dos fármacos , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antivirais/química , Antivirais/farmacologia , COVID-19/fisiopatologia , Humanos , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/química , Replicação Viral/efeitos dos fármacos
8.
Cells ; 10(5)2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-34066434

RESUMO

Viral pathogens often exploit host cell regulatory and signaling pathways to ensure an optimal environment for growth and survival. Several studies have suggested that 5'-adenosine monophosphate-activated protein kinase (AMPK), an intracellular serine/threonine kinase, plays a significant role in the modulation of infection. Traditionally, AMPK is a key energy regulator of cell growth and proliferation, host autophagy, stress responses, metabolic reprogramming, mitochondrial homeostasis, fatty acid ß-oxidation and host immune function. In this review, we highlight the modulation of host AMPK by various viruses under physiological conditions. These intracellular pathogens trigger metabolic changes altering AMPK signaling activity that then facilitates or inhibits viral replication. Considering the COVID-19 pandemic, understanding the regulation of AMPK signaling following infection can shed light on the development of more effective therapeutic strategies against viral infectious diseases.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antivirais/farmacologia , Transdução de Sinais/imunologia , Viroses/imunologia , Antivirais/uso terapêutico , Autofagia/efeitos dos fármacos , Autofagia/imunologia , COVID-19/tratamento farmacológico , COVID-19/epidemiologia , COVID-19/imunologia , Proliferação de Células/efeitos dos fármacos , Desenvolvimento de Medicamentos , Humanos , Pandemias/prevenção & controle , SARS-CoV-2/imunologia , Transdução de Sinais/efeitos dos fármacos , Viroses/tratamento farmacológico , Replicação Viral/efeitos dos fármacos , Replicação Viral/imunologia
9.
Int J Mol Sci ; 22(10)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067854

RESUMO

Numerous viruses hijack cellular protein trafficking pathways to mediate cell entry or to rearrange membrane structures thereby promoting viral replication and antagonizing the immune response. Adaptor protein complexes (AP), which mediate protein sorting in endocytic and secretory transport pathways, are one of the conserved viral targets with many viruses possessing AP-interacting motifs. We present here different mechanisms of viral interference with AP complexes and the functional consequences that allow for efficient viral propagation and evasion of host immune defense. The ubiquity of this phenomenon is evidenced by the fact that there are representatives for AP interference in all major viral families, covered in this review. The best described examples are interactions of human immunodeficiency virus and human herpesviruses with AP complexes. Several other viruses, like Ebola, Nipah, and SARS-CoV-2, are pointed out as high priority disease-causative agents supporting the need for deeper understanding of virus-AP interplay which can be exploited in the design of novel antiviral therapies.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , HIV-1/metabolismo , Herpesviridae/metabolismo , SARS-CoV-2/metabolismo , Ebolavirus/metabolismo , Endocitose , Humanos , Vírus Nipah/metabolismo , Transporte Proteico , Liberação de Vírus , Replicação Viral
10.
Biomolecules ; 11(5)2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069869

RESUMO

Several RNA viruses, including SARS-CoV-2, can infect or use the eye as an entry portal to cause ocular or systemic diseases. Povidone-Iodine (PVP-I) is routinely used during ocular surgeries and eye banking as a cost-effective disinfectant due to its broad-spectrum antimicrobial activity, including against viruses. However, whether PVP-I can exert antiviral activities in virus-infected cells remains elusive. In this study, using Zika (ZIKV) and Chikungunya (CHIKV) virus infection of human corneal and retinal pigment epithelial cells, we report antiviral mechanisms of PVP-I. Our data showed that PVP-I, even at the lowest concentration (0.01%), drastically reduced viral replication in corneal and retinal cells without causing cellular toxicity. Antiviral effects of PVP-I against ZIKV and CHIKV were mediated by direct viral inactivation, thus attenuating the ability of the virus to infect host cells. Moreover, one-minute PVP-I exposure of infected ocular cells drastically reduced viral replication and the production of infectious progeny virions. Furthermore, viral-induced (CHIKV) expression of inflammatory genes (TNF-α, IL-6, IL-8, and IL1ß) were markedly reduced in PVP-I treated corneal epithelial cells. Together, our results demonstrate potent antiviral effects of PVP-I against ZIKV and CHIKV infection of ocular cells. Thus, a low dose of PVP-I can be used during tissue harvesting for corneal transplants to prevent potential transmission of RNA viruses via infected cells.


Assuntos
Antivirais/farmacologia , Povidona-Iodo/farmacologia , Vírus de RNA/fisiologia , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular , Vírus Chikungunya/fisiologia , Chlorocebus aethiops , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/virologia , SARS-CoV-2/fisiologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Células Vero , Zika virus/fisiologia
11.
Int J Mol Sci ; 22(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073578

RESUMO

Ceramide is a lipid messenger at the heart of sphingolipid metabolism. In concert with its metabolizing enzymes, particularly sphingomyelinases, it has key roles in regulating the physical properties of biological membranes, including the formation of membrane microdomains. Thus, ceramide and its related molecules have been attributed significant roles in nearly all steps of the viral life cycle: they may serve directly as receptors or co-receptors for viral entry, form microdomains that cluster entry receptors and/or enable them to adopt the required conformation or regulate their cell surface expression. Sphingolipids can regulate all forms of viral uptake, often through sphingomyelinase activation, and mediate endosomal escape and intracellular trafficking. Ceramide can be key for the formation of viral replication sites. Sphingomyelinases often mediate the release of new virions from infected cells. Moreover, sphingolipids can contribute to viral-induced apoptosis and morbidity in viral diseases, as well as virus immune evasion. Alpha-galactosylceramide, in particular, also plays a significant role in immune modulation in response to viral infections. This review will discuss the roles of ceramide and its related molecules in the different steps of the viral life cycle. We will also discuss how novel strategies could exploit these for therapeutic benefit.


Assuntos
Ceramidas/metabolismo , HIV-1/metabolismo , Vírus da Influenza A/metabolismo , SARS-CoV-2/metabolismo , Viroses/metabolismo , Viroses/virologia , Apoptose/efeitos dos fármacos , Apoptose/imunologia , Ceramidas/química , Regulação Viral da Expressão Gênica , HIV-1/patogenicidade , Humanos , Imunomodulação , Vírus da Influenza A/patogenicidade , SARS-CoV-2/patogenicidade , Vírion/crescimento & desenvolvimento , Viroses/imunologia , Internalização do Vírus , Replicação Viral/efeitos dos fármacos , Replicação Viral/imunologia
12.
Cells ; 10(6)2021 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-34070971

RESUMO

The recent SARS-CoV-2 pandemic has refocused attention to the betacoronaviruses, only eight years after the emergence of another zoonotic betacoronavirus, the Middle East respiratory syndrome coronavirus (MERS-CoV). While the wild source of SARS-CoV-2 may be disputed, for MERS-CoV, dromedaries are considered as source of zoonotic human infections. Testing 100 immune-response genes in 121 dromedaries from United Arab Emirates (UAE) for potential association with present MERS-CoV infection, we identified candidate genes with important functions in the adaptive, MHC-class I (HLA-A-24-like) and II (HLA-DPB1-like), and innate immune response (PTPN4, MAGOHB), and in cilia coating the respiratory tract (DNAH7). Some of these genes previously have been associated with viral replication in SARS-CoV-1/-2 in humans, others have an important role in the movement of bronchial cilia. These results suggest similar host genetic pathways associated with these betacoronaviruses, although further work is required to better understand the MERS-CoV disease dynamics in both dromedaries and humans.


Assuntos
Imunidade Adaptativa/genética , Camelus/virologia , Doenças Transmissíveis Emergentes/imunologia , Infecções por Coronavirus/imunologia , Imunidade Inata/genética , Zoonoses/imunologia , Animais , Anticorpos Antivirais , Brônquios/citologia , Brônquios/fisiologia , COVID-19/genética , COVID-19/imunologia , COVID-19/virologia , Camelus/genética , Camelus/imunologia , Cílios/fisiologia , Doenças Transmissíveis Emergentes/genética , Doenças Transmissíveis Emergentes/transmissão , Doenças Transmissíveis Emergentes/virologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Reservatórios de Doenças/virologia , Feminino , Predisposição Genética para Doença , Interações entre Hospedeiro e Microrganismos/genética , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Masculino , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/isolamento & purificação , Coronavírus da Síndrome Respiratória do Oriente Médio/patogenicidade , Mucosa Respiratória/citologia , Mucosa Respiratória/fisiologia , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Emirados Árabes Unidos , Replicação Viral/genética , Replicação Viral/imunologia , Zoonoses/genética , Zoonoses/transmissão , Zoonoses/virologia
13.
Genes (Basel) ; 12(6)2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073716

RESUMO

The current SARS-CoV-2 pandemic is still threatening humankind. Despite first successes in vaccine development and approval, no antiviral treatment is available for COVID-19 patients. The success is further tarnished by the emergence and spreading of mutation variants of SARS-CoV-2, for which some vaccines have lower efficacy. This highlights the urgent need for antiviral therapies even more. This article describes how the genome-scale metabolic model (GEM) of the host-virus interaction of human alveolar macrophages and SARS-CoV-2 was refined by incorporating the latest information about the virus's structural proteins and the mutant variants B.1.1.7, B.1.351, B.1.28, B.1.427/B.1.429, and B.1.617. We confirmed the initially identified guanylate kinase as a potential antiviral target with this refined model and identified further potential targets from the purine and pyrimidine metabolism. The model was further extended by incorporating the virus' lipid requirements. This opened new perspectives for potential antiviral targets in the altered lipid metabolism. Especially the phosphatidylcholine biosynthesis seems to play a pivotal role in viral replication. The guanylate kinase is even a robust target in all investigated mutation variants currently spreading worldwide. These new insights can guide laboratory experiments for the validation of identified potential antiviral targets. Only the combination of vaccines and antiviral therapies will effectively defeat this ongoing pandemic.


Assuntos
COVID-19/metabolismo , COVID-19/virologia , Metabolismo Energético , Genoma Viral , Guanilato Quinases/metabolismo , Interações Hospedeiro-Patógeno , Mutação , SARS-CoV-2/genética , Antivirais/farmacologia , Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , COVID-19/genética , Técnicas de Silenciamento de Genes , Humanos , Metabolismo dos Lipídeos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/virologia , SARS-CoV-2/efeitos dos fármacos , Carga Viral , Replicação Viral
14.
Commun Biol ; 4(1): 590, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34002013

RESUMO

The novel betacoronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a worldwide pandemic (COVID-19) after emerging in Wuhan, China. Here we analyzed public host and viral RNA sequencing data to better understand how SARS-CoV-2 interacts with human respiratory cells. We identified genes, isoforms and transposable element families that are specifically altered in SARS-CoV-2-infected respiratory cells. Well-known immunoregulatory genes including CSF2, IL32, IL-6 and SERPINA3 were differentially expressed, while immunoregulatory transposable element families were upregulated. We predicted conserved interactions between the SARS-CoV-2 genome and human RNA-binding proteins such as the heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) and eukaryotic initiation factor 4 (eIF4b). We also identified a viral sequence variant with a statistically significant skew associated with age of infection, that may contribute to intracellular host-pathogen interactions. These findings can help identify host mechanisms that can be targeted by prophylactics and/or therapeutics to reduce the severity of COVID-19.


Assuntos
/genética , Biologia Computacional/métodos , Interações Hospedeiro-Patógeno/genética , Pandemias , /genética , Sítios de Ligação , Citocinas/genética , Bases de Dados Genéticas , Regulação da Expressão Gênica , Genoma Viral , Humanos , RNA Viral/genética , RNA Viral/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , RNA-Seq , Serpinas/genética , Transdução de Sinais/genética , Transcriptoma , Replicação Viral/genética
16.
Braz J Med Biol Res ; 54(7): e10240, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34008751

RESUMO

Dengue is the most important arthropod-borne viral disease worldwide. Infection with any of the four dengue virus (DENV) serotypes can be asymptomatic or lead to disease with clinical symptoms ranging from undifferentiated and self-limiting fever to severe dengue disease, which can be fatal in some cases. Currently, no specific antiviral compound is available for treating DENV. The aim of this study was to identify compounds in plants from Paraguayan folk medicine with inhibitory effects against DENV. We found high virucidal activity (50% maximal effective concentration (EC50) value of 24.97 µg/mL) against DENV-2 in the ethanolic extract of the roots of Solanum sisymbriifolium Lam. (Solanaceae) without an evident cytotoxic effect on Vero E6 cells. Three saponins isolated from the root extract showed virucidal effects (EC50 values ranging from 24.9 to 35.1 µg/mL) against DENV-2. Additionally, the saponins showed inhibitory activity against yellow fever virus (EC50 values ranging from 126 to 302.6 µg/mL), the prototype virus of the Flavivirus genus, suggesting that they may also be effective against other members of this genus. Consequently, these saponins may be lead compounds for the development of antiviral agents.


Assuntos
Vírus da Dengue , Saponinas , Solanum , Antivirais/farmacologia , Saponinas/farmacologia , Replicação Viral , Vírus da Febre Amarela
17.
Nat Commun ; 12(1): 3040, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34031403

RESUMO

All herpesviruses encode a conserved DNA polymerase that is required for viral genome replication and serves as an important therapeutic target. Currently available herpesvirus therapies include nucleoside and non-nucleoside inhibitors (NNI) that target the DNA-bound state of herpesvirus polymerase and block replication. Here we report the ternary complex crystal structure of Herpes Simplex Virus 1 DNA polymerase bound to DNA and a 4-oxo-dihydroquinoline NNI, PNU-183792 (PNU), at 3.5 Å resolution. PNU bound at the polymerase active site, displacing the template strand and inducing a conformational shift of the fingers domain into an open state. These results demonstrate that PNU inhibits replication by blocking association of dNTP and stalling the enzyme in a catalytically incompetent conformation, ultimately acting as a nucleotide competing inhibitor (NCI). Sequence conservation of the NCI binding pocket further explains broad-spectrum activity while a direct interaction between PNU and residue V823 rationalizes why mutations at this position result in loss of inhibition.


Assuntos
DNA Polimerase Dirigida por DNA/química , DNA Polimerase Dirigida por DNA/efeitos dos fármacos , DNA Polimerase Dirigida por DNA/genética , Herpesviridae/efeitos dos fármacos , Herpesviridae/enzimologia , Antivirais/farmacologia , Sítios de Ligação , DNA Polimerase Dirigida por DNA/metabolismo , Farmacorresistência Viral/efeitos dos fármacos , Exodesoxirribonucleases , Nucleotídeos , Quinolinas/farmacologia , Proteínas Virais , Replicação Viral
18.
Virologie (Montrouge) ; 25(2): 63-92, 2021 04 01.
Artigo em Francês | MEDLINE | ID: mdl-33973852

RESUMO

Epigenetics play an important role in viral replication and in viral associated pathogenesis. In fact, viruses interact with epigenetic factors to promote the viral replication by stimulating the entry into the lytic cycle, but also by promoting viral latency. Furthermore, epigenetics control the immune response implemented by the host to counteract viral infections. Thus, epigenetic modifications are identified as potential therapeutic targets to control viral infections. Several studies have already shown the efficiency of inhibitors of histone deacetylases, demethylases, acetyltransferases and methyltransferases, as well as inhibitors of DNA methyltransferases in viral infections repression or in latency reactivation. In this review, we will examine the epigenetic regulation of viral infections by several DNA viruses, e.g. HSV, EBV, HCMV, KSHV, HBV, HPV and HAdV, and RNA viruses, e.g. HCV, HIV, IAV and CoV. Also, we will discuss the potential use of therapeutic approaches targeting epigenetics for the control of viral infections.


Assuntos
Herpesvirus Humano 8 , Viroses , Epigênese Genética , Humanos , Viroses/tratamento farmacológico , Viroses/genética , Latência Viral , Replicação Viral/genética
19.
C R Biol ; 343(4): 79-89, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33988325

RESUMO

Chikungunya is an infectious disease caused by the chikungunya virus (CHIKV), an alphavirus transmitted to humans by Aedes mosquitoes, and for which there is no licensed vaccine nor antiviral treatments. By using a loss-of-function genetic screen, we have recently identified the FHL1 protein as an essential host factor for CHIKV tropism and pathogenesis. FHL1 is highly expressed in muscles cells and fibroblasts, the main CHIKV-target cells. FHL1 interacts with the viral protein nsP3 and plays a critical role in CHIKV genome amplification. Experiments in vivo performed in FHL1-deficient mice have shown that these animals are resistant to infection and do not develop muscular lesions. Altogether these observations, published in the journal Nature [1], show that FHL1 is a key host factor for CHIKV pathogenesis and identify the interaction between FHL1 and nsP3 as a promising target for the development of new antiviral strategies.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Animais , Vírus Chikungunya/genética , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas com Domínio LIM , Camundongos , Proteínas Musculares , Tropismo , Proteínas não Estruturais Virais , Replicação Viral
20.
Nat Commun ; 12(1): 2475, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33931637

RESUMO

An innovative approach to eliminate HIV-1-infected cells emerging out of latency, the major hurdle to HIV-1 cure, is to pharmacologically reactivate viral expression and concomitantly trigger intracellular pro-apoptotic pathways in order to selectively induce cell death (ICD) of infected cells, without reliance on the extracellular immune system. In this work, we demonstrate the effect of DDX3 inhibitors on selectively inducing cell death in latent HIV-1-infected cell lines, primary CD4+ T cells and in CD4+ T cells from cART-suppressed people living with HIV-1 (PLWHIV). We used single-cell FISH-Flow technology to characterise the contribution of viral RNA to inducing cell death. The pharmacological targeting of DDX3 induced HIV-1 RNA expression, resulting in phosphorylation of IRF3 and upregulation of IFNß. DDX3 inhibition also resulted in the downregulation of BIRC5, critical to cell survival during HIV-1 infection, and selectively induced apoptosis in viral RNA-expressing CD4+ T cells but not bystander cells. DDX3 inhibitor treatment of CD4+ T cells from PLWHIV resulted in an approximately 50% reduction of the inducible latent HIV-1 reservoir by quantitation of HIV-1 RNA, by FISH-Flow, RT-qPCR and TILDA. This study provides proof of concept for pharmacological reversal of latency coupled to induction of apoptosis towards the elimination of the inducible reservoir.


Assuntos
Apoptose/efeitos dos fármacos , Azepinas/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , RNA Helicases DEAD-box/metabolismo , Infecções por HIV/imunologia , HIV-1/metabolismo , Imidazóis/farmacologia , Latência Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Antirretrovirais/farmacologia , Apoptose/genética , Azepinas/química , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/virologia , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , RNA Helicases DEAD-box/antagonistas & inibidores , RNA Helicases DEAD-box/química , Inibidores Enzimáticos/farmacologia , Infecções por HIV/genética , Infecções por HIV/metabolismo , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Imidazóis/química , Hibridização in Situ Fluorescente , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/metabolismo , Células Jurkat , Simulação de Acoplamento Molecular , RNA Viral/metabolismo , Análise de Célula Única , Survivina/metabolismo , Ativação Viral/efeitos dos fármacos , Replicação Viral/genética
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