Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 68.243
Filtrar
1.
J Transl Med ; 18(1): 329, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32867854

RESUMO

BACKGROUND: The new Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), which was first detected in Wuhan (China) in December of 2019 is responsible for the current global pandemic. Phylogenetic analysis revealed that it is similar to other betacoronaviruses, such as SARS-CoV and Middle-Eastern Respiratory Syndrome, MERS-CoV. Its genome is ∼ 30 kb in length and contains two large overlapping polyproteins, ORF1a and ORF1ab that encode for several structural and non-structural proteins. The non-structural protein 1 (nsp1) is arguably the most important pathogenic determinant, and previous studies on SARS-CoV indicate that it is both involved in viral replication and hampering the innate immune system response. Detailed experiments of site-specific mutagenesis and in vitro reconstitution studies determined that the mechanisms of action are mediated by (a) the presence of specific amino acid residues of nsp1 and (b) the interaction between the protein and the host's small ribosomal unit. In fact, substitution of certain amino acids resulted in reduction of its negative effects. METHODS: A total of 17,928 genome sequences were obtained from the GISAID database (December 2019 to July 2020) from patients infected by SARS-CoV-2 from different areas around the world. Genomes alignment was performed using MAFFT (REFF) and the nsp1 genomic regions were identified using BioEdit and verified using BLAST. Nsp1 protein of SARS-CoV-2 with and without deletion have been subsequently modelled using I-TASSER. RESULTS: We identified SARS-CoV-2 genome sequences, from several Countries, carrying a previously unknown deletion of 9 nucleotides in position 686-694, corresponding to the AA position 241-243 (KSF). This deletion was found in different geographical areas. Structural prediction modelling suggests an effect on the C-terminal tail structure. CONCLUSIONS: Modelling analysis of a newly identified deletion of 3 amino acids (KSF) of SARS-CoV-2 nsp1 suggests that this deletion could affect the structure of the C-terminal region of the protein, important for regulation of viral replication and negative effect on host's gene expression. In addition, substitution of the two amino acids (KS) from nsp1 of SARS-CoV was previously reported to revert loss of interferon-alpha expression. The deletion that we describe indicates that SARS-CoV-2 is undergoing profound genomic changes. It is important to: (i) confirm the spreading of this particular viral strain, and potentially of strains with other deletions in the nsp1 protein, both in the population of asymptomatic and pauci-symptomatic subjects, and (ii) correlate these changes in nsp1 with potential decreased viral pathogenicity.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/virologia , Pneumonia Viral/virologia , Deleção de Sequência , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos , Sequência de Bases , Betacoronavirus/patogenicidade , Doenças Transmissíveis Emergentes/virologia , Infecções por Coronavirus/epidemiologia , Frequência do Gene , Genoma Viral , Geografia , Humanos , Lisina/genética , Modelos Moleculares , Pandemias/estatística & dados numéricos , Fenilalanina/genética , Pneumonia Viral/epidemiologia , Domínios Proteicos/genética , Serina/genética , Proteínas não Estruturais Virais/química , Virulência/genética , Replicação Viral/genética
2.
Rev Med Liege ; 75(9): 582-587, 2020 Sep.
Artigo em Francês | MEDLINE | ID: mdl-32909408

RESUMO

The antiretroviral therapy (ART) has proven its effectiveness in improving the life expectancy of people infected with human immunodeficiency virus (HIV). Based on the inhibition of HIV replication, ART ensures the reduction of plasma viral load to undetectable levels on long-term. Unfortunately, once ART is interrupted, the viral load rises up. Consequently, the therapy remains not curative. The reasons for this failure lie in the presence of latent reservoirs of the virus and/or the presence of ongoing replication, responsible for the persistence of the virus. This ongoing replication despite ongoing therapy has been demonstrated in sanctuary sites where the penetration of antiretroviral drugs is suboptimal. Moreover, some treatment intensification studies, mostly through addition of an integrase inhibitor, transiently resulted in increases in HIV replication by-products, highlighting that such strategies could reduce ongoing replication. Although the debate is still open, confirming the presence of this ongoing replication and finding strategies to eliminate it would be part of the key to a cure for HIV.


Assuntos
Infecções por HIV , Terapia Antirretroviral de Alta Atividade , Humanos , Carga Viral , Replicação Viral
3.
BMJ ; 370: m2200, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873599

RESUMO

Hepatitis B virus (HBV) infection causes chronic hepatitis and has long term complications. Individuals ever infected with HBV are at risk of viral reactivation under certain circumstances. This review summarizes studies on HBV persistence and reactivation with a focus on the definitions and mechanisms. Emphasis is placed on the interplay between HBV replication and host immunity as this interplay determines the patterns of persistence following viral acquisition. Chronic infections exhibit as overt persistence when a defective immune response fails to control the viral replication. The HBV genome persists despite an immune response in the form of covalently closed circular DNA (cccDNA) and integrated DNA, rendering an occult state of viral persistence in individuals whose infection appears to have been resolved. We have described HBV reactivation that occurs because of changes in the virus or the immune system. This review aims to raise the awareness of HBV reactivation and to understand how HBV persists, and discusses the risks of HBV reactivation in a variety of clinical settings.


Assuntos
Vírus da Hepatite B/imunologia , Hepatite B Crônica/virologia , Replicação Viral/imunologia , Animais , DNA Viral/sangue , Saúde Global , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/imunologia , Humanos , Imunossupressão , Imunossupressores/uso terapêutico , Fatores de Risco
4.
Mol Cell ; 79(5): 710-727, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32853546

RESUMO

The coronavirus disease 2019 (COVID-19) that is wreaking havoc on worldwide public health and economies has heightened awareness about the lack of effective antiviral treatments for human coronaviruses (CoVs). Many current antivirals, notably nucleoside analogs (NAs), exert their effect by incorporation into viral genomes and subsequent disruption of viral replication and fidelity. The development of anti-CoV drugs has long been hindered by the capacity of CoVs to proofread and remove mismatched nucleotides during genome replication and transcription. Here, we review the molecular basis of the CoV proofreading complex and evaluate its potential as a drug target. We also consider existing nucleoside analogs and novel genomic techniques as potential anti-CoV therapeutics that could be used individually or in combination to target the proofreading mechanism.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Genoma Viral , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/epidemiologia , RNA Viral/genética , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/química , Monofosfato de Adenosina/uso terapêutico , Alanina/análogos & derivados , Alanina/química , Alanina/uso terapêutico , Amidas/química , Amidas/uso terapêutico , Antivirais/química , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Infecções por Coronavirus/virologia , Humanos , Terapia de Alvo Molecular/métodos , Mutação , Pneumonia Viral/virologia , Pirazinas/química , Pirazinas/uso terapêutico , RNA Viral/antagonistas & inibidores , RNA Viral/metabolismo , Ribonucleosídeos/química , Ribonucleosídeos/uso terapêutico , Índice de Gravidade de Doença , Transcrição Genética , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos
5.
Nat Commun ; 11(1): 4282, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855413

RESUMO

The main protease, Mpro (or 3CLpro) in SARS-CoV-2 is a viable drug target because of its essential role in the cleavage of the virus polypeptide. Feline infectious peritonitis, a fatal coronavirus infection in cats, was successfully treated previously with a prodrug GC376, a dipeptide-based protease inhibitor. Here, we show the prodrug and its parent GC373, are effective inhibitors of the Mpro from both SARS-CoV and SARS-CoV-2 with IC50 values in the nanomolar range. Crystal structures of SARS-CoV-2 Mpro with these inhibitors have a covalent modification of the nucleophilic Cys145. NMR analysis reveals that inhibition proceeds via reversible formation of a hemithioacetal. GC373 and GC376 are potent inhibitors of SARS-CoV-2 replication in cell culture. They are strong drug candidates for the treatment of human coronavirus infections because they have already been successful in animals. The work here lays the framework for their use in human trials for the treatment of COVID-19.


Assuntos
Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Coronavirus Felino/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Células A549 , Animais , Antivirais/química , Betacoronavirus/enzimologia , Sítios de Ligação , Chlorocebus aethiops , Coronavirus Felino/enzimologia , Cristalografia por Raios X , Cisteína Endopeptidases/química , Efeito Citopatogênico Viral/efeitos dos fármacos , Reposicionamento de Medicamentos , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Pró-Fármacos , Inibidores de Proteases/química , Pirrolidinas/química , Pirrolidinas/farmacologia , Vírus da SARS/efeitos dos fármacos , Vírus da SARS/enzimologia , Células Vero , Proteínas não Estruturais Virais/química , Replicação Viral/efeitos dos fármacos
6.
J Exp Med ; 217(12)2020 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-32750141

RESUMO

Severe acute respiratory syndrome-coronavirus 2 (SARS-Cov-2) has caused over 13,000,000 cases of coronavirus disease (COVID-19) with a significant fatality rate. Laboratory mice have been the stalwart of therapeutic and vaccine development; however, they do not support infection by SARS-CoV-2 due to the virus's inability to use the mouse orthologue of its human entry receptor angiotensin-converting enzyme 2 (hACE2). While hACE2 transgenic mice support infection and pathogenesis, these mice are currently limited in availability and are restricted to a single genetic background. Here we report the development of a mouse model of SARS-CoV-2 based on adeno-associated virus (AAV)-mediated expression of hACE2. These mice support viral replication and exhibit pathological findings found in COVID-19 patients. Moreover, we show that type I interferons do not control SARS-CoV-2 replication in vivo but are significant drivers of pathological responses. Thus, the AAV-hACE2 mouse model enables rapid deployment for in-depth analysis following robust SARS-CoV-2 infection with authentic patient-derived virus in mice of diverse genetic backgrounds.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/metabolismo , Modelos Animais de Doenças , Interferon Tipo I/metabolismo , Camundongos/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Animais , Linhagem Celular Tumoral , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Dependovirus/genética , Feminino , Humanos , Inflamação/metabolismo , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pandemias , Infecções por Parvoviridae/metabolismo , Infecções por Parvoviridae/virologia , Peptidil Dipeptidase A/genética , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Transdução de Sinais/genética , Replicação Viral/genética
7.
Methods Mol Biol ; 2203: 1-29, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32833200

RESUMO

Coronaviruses (CoVs), enveloped positive-sense RNA viruses, are characterized by club-like spikes that project from their surface, an unusually large RNA genome, and a unique replication strategy. CoVs cause a variety of diseases in mammals and birds ranging from enteritis in cows and pigs, and upper respiratory tract and kidney disease in chickens to lethal human respiratory infections. Most recently, the novel coronavirus, SARS-CoV-2, which was first identified in Wuhan, China in December 2019, is the cause of a catastrophic pandemic, COVID-19, with more than 8 million infections diagnosed worldwide by mid-June 2020. Here we provide a brief introduction to CoVs discussing their replication, pathogenicity, and current prevention and treatment strategies. We will also discuss the outbreaks of the highly pathogenic Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV), which are relevant for understanding COVID-19.


Assuntos
Doenças dos Animais/virologia , Betacoronavirus/fisiologia , Galinhas/virologia , Infecções por Coronavirus/virologia , Coronavirus/fisiologia , Pneumonia Viral/virologia , Síndrome Respiratória Aguda Grave/virologia , Doenças dos Animais/diagnóstico , Doenças dos Animais/epidemiologia , Doenças dos Animais/prevenção & controle , Animais , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Bovinos , Coronavirus/genética , Coronavirus/patogenicidade , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Coronavírus da Síndrome Respiratória do Oriente Médio/patogenicidade , Coronavírus da Síndrome Respiratória do Oriente Médio/fisiologia , Pandemias/prevenção & controle , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Vírus da SARS/genética , Vírus da SARS/patogenicidade , Vírus da SARS/fisiologia , Síndrome Respiratória Aguda Grave/diagnóstico , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/prevenção & controle , Glicoproteína da Espícula de Coronavírus/genética , Suínos , Vírion , Replicação Viral
8.
Nat Commun ; 11(1): 3896, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32753727

RESUMO

The outbreak of Zika virus (ZIKV) in 2016 created worldwide health emergency which demand urgent research efforts on understanding the virus biology and developing therapeutic strategies. Here, we present a time-resolved chemical proteomic strategy to track the early-stage entry of ZIKV into host cells. ZIKV was labeled on its surface with a chemical probe, which carries a photocrosslinker to covalently link virus-interacting proteins in living cells on UV exposure at different time points, and a biotin tag for subsequent enrichment and mass spectrometric identification of the receptor or other host proteins critical for virus internalization. We identified Neural Cell Adhesion Molecule (NCAM1) as a potential ZIKV receptor and further validated it through overexpression, knockout, and inhibition of NCAM1 in Vero cells and human glioblastoma cells U-251 MG. Collectively, the strategy can serve as a universal tool to map virus entry pathways and uncover key interacting proteins.


Assuntos
Moléculas de Adesão de Célula Nervosa/metabolismo , Proteômica , Receptores Virais/metabolismo , Internalização do Vírus , Replicação Viral/fisiologia , Zika virus/fisiologia , Animais , Antígeno CD56/genética , Antígeno CD56/metabolismo , Linhagem Celular Tumoral , Chlorocebus aethiops , Técnicas de Inativação de Genes , Glioblastoma , Células HEK293 , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Moléculas de Adesão de Célula Nervosa/genética , Células Vero , Proteínas Virais/metabolismo , Ligação Viral , Infecção por Zika virus/virologia
9.
Methods Mol Biol ; 2203: 205-221, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32833214

RESUMO

We have developed a screening system using the yeast Saccharomyces cerevisiae to identify eukaryotic genes involved in the replication of mammalian viruses. Yeast come with various advantages, but in the context of coronavirus research and the system outlined here, they are simple and easy to work with and can be used at biosafety level 2. The system involves inducible expression of individual viral proteins and identification of detrimental phenotypes in the yeast. Yeast knockout and overexpression libraries can then be used for genome-wide screening of host proteins that provide a suppressor phenotype. From the yeast hits, a narrowed list of candidate genes can be produced to investigate for roles in viral replication. Since the system only requires expression of viral proteins, it can be used for any current or emerging virus, regardless of biocontainment requirements and ability to culture the virus. In this chapter, we will outline the protocols that can be used to take advantage of S. cerevisiae as a tool to advance understanding of how viruses interact with eukaryotic cells.


Assuntos
Coronavirus/fisiologia , Coronavirus/patogenicidade , Interações Hospedeiro-Patógeno/fisiologia , Saccharomyces cerevisiae/genética , Plasmídeos , Proteínas Virais/genética , Proteínas Virais/isolamento & purificação , Replicação Viral
10.
Virology ; 548: 59-72, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838947

RESUMO

Methylation of the N6 position of adenosine (m6A) is a widespread RNA modification that is critical for various physiological and pathological processes. Although this modification was also found in the RNA of several viruses almost 40 years ago, its biological functions during viral infection have been elucidated recently. Here, we investigated the effects of viral and host RNA methylation during porcine epidemic diarrhea virus (PEDV) infection. The results demonstrated that the m6A modification was abundant in the PEDV genome and the host methyltransferases METTL3 and METTL14 and demethylase FTO were involved in the regulation of viral replication. The knockdown of the methyltransferases increased PEDV replication while silencing the demethylase decreased PEDV output. Moreover, the proteins of the YTHDF family regulated the PEDV replication by affecting the stability of m6A-modified viral RNA. In particular, PEDV infection could trigger an increasement of m6A in host RNA and decrease the expression of FTO. The m6A modification sites in mRNAs and target genes were also altered during PEDV infection. Additionally, part of the host responses to PEDV infection was controlled by m6A modification, which could be reversed by the expression of FTO. Taken together, our results identified the role of m6A modification in PEDV replication and interactions with the host.


Assuntos
Adenosina/análogos & derivados , Infecções por Coronavirus/veterinária , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Vírus da Diarreia Epidêmica Suína/fisiologia , Doenças dos Suínos/genética , Doenças dos Suínos/virologia , Replicação Viral , Adenosina/metabolismo , Animais , Linhagem Celular , Chlorocebus aethiops , Genoma Viral , Metilação , Vírus da Diarreia Epidêmica Suína/ultraestrutura , Ligação Proteica , RNA Viral , Proteínas de Ligação a RNA/metabolismo , Suínos , Células Vero
11.
Nat Commun ; 11(1): 4252, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843628

RESUMO

The 2019 novel respiratory virus (SARS-CoV-2) causes COVID-19 with rapid global socioeconomic disruptions and disease burden to healthcare. The COVID-19 and previous emerging virus outbreaks highlight the urgent need for broad-spectrum antivirals. Here, we show that a defensin-like peptide P9R exhibited potent antiviral activity against pH-dependent viruses that require endosomal acidification for virus infection, including the enveloped pandemic A(H1N1)pdm09 virus, avian influenza A(H7N9) virus, coronaviruses (SARS-CoV-2, MERS-CoV and SARS-CoV), and the non-enveloped rhinovirus. P9R can significantly protect mice from lethal challenge by A(H1N1)pdm09 virus and shows low possibility to cause drug-resistant virus. Mechanistic studies indicate that the antiviral activity of P9R depends on the direct binding to viruses and the inhibition of virus-host endosomal acidification, which provides a proof of concept that virus-binding alkaline peptides can broadly inhibit pH-dependent viruses. These results suggest that the dual-functional virus- and host-targeting P9R can be a promising candidate for combating pH-dependent respiratory viruses.


Assuntos
Antivirais/farmacologia , Coronavirus/efeitos dos fármacos , Vírus da Influenza A/efeitos dos fármacos , Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Antivirais/química , Antivirais/metabolismo , Antivirais/uso terapêutico , Linhagem Celular , Endossomos/química , Endossomos/efeitos dos fármacos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Vírus da Influenza A/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Peptídeos/uso terapêutico , Ligação Proteica , Conformação Proteica , Rhinovirus/efeitos dos fármacos , Rhinovirus/metabolismo , Carga Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
12.
Int J Mol Sci ; 21(16)2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32824753

RESUMO

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 and its associated pathology, COVID-19, have been of particular concerns these last months due to the worldwide burden they represent. The number of cases requiring intensive care being the critical point in this epidemic, a better understanding of the pathophysiology leading to these severe cases is urgently needed. Tissue lesions can be caused by the pathogen or can be driven by an overwhelmed immune response. Focusing on SARS-CoV-2, we and others have observed that this virus can trigger indeed an immune response that can be dysregulated in severe patients and leading to further injury to multiple organs. The purpose of the review is to bring to light the current knowledge about SARS-CoV-2 virologic and immunologic features. Thus, we address virus biology, life cycle, tropism for many organs and how ultimately it will affect several host biological and physiological functions, notably the immune response. Given that therapeutic avenues are now highly warranted, we also discuss the immunotherapies available to manage the infection and the clinical outcomes.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Fatores Etários , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/terapia , Citocinas/sangue , Humanos , Imunoterapia/métodos , Pulmão/patologia , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Pneumonia Viral/terapia , RNA Replicase/metabolismo , Proteínas não Estruturais Virais/metabolismo , Tropismo Viral/fisiologia , Montagem de Vírus/fisiologia , Replicação Viral/fisiologia
13.
Nat Commun ; 11(1): 4070, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792502

RESUMO

Human astroviruses are small non-enveloped viruses with positive-sense single-stranded RNA genomes. Astroviruses cause acute gastroenteritis in children worldwide and have been associated with encephalitis and meningitis in immunocompromised individuals. It is still unknown how astrovirus particles exit infected cells following replication. Through comparative genomic analysis and ribosome profiling we here identify and confirm the expression of a conserved alternative-frame ORF, encoding the protein XP. XP-knockout astroviruses are attenuated and pseudo-revert on passaging. Further investigation into the function of XP revealed plasma and trans Golgi network membrane-associated roles in virus assembly and/or release through a viroporin-like activity. XP-knockout replicons have only a minor replication defect, demonstrating the role of XP at late stages of infection. The discovery of XP advances our knowledge of these important human viruses and opens an additional direction of research into their life cycle and pathogenesis.


Assuntos
Canais Iônicos/metabolismo , Mamastrovirus/metabolismo , Proteínas não Estruturais Virais/metabolismo , Animais , Linhagem Celular , Cricetinae , Eletroforese em Gel de Poliacrilamida , Genômica/métodos , Células HeLa , Humanos , Immunoblotting , Imunoprecipitação , Canais Iônicos/genética , Mamastrovirus/genética , Microscopia de Fluorescência , Plasmídeos/genética , Ribossomos , Proteínas não Estruturais Virais/genética , Replicação Viral/genética , Replicação Viral/fisiologia
14.
Biochemistry ; 59(33): 3038-3043, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32786401

RESUMO

The COVID-19 pandemic threatens to overwhelm healthcare systems around the world. The only current FDA-approved treatment, which directly targets the virus, is the ProTide prodrug remdesivir. In its activated form, remdesivir prevents viral replication by inhibiting the essential RNA-dependent RNA polymerase. Like other ProTide prodrugs, remdesivir contains a chiral phosphorus center. The initial selection of the (SP)-diastereomer for remdesivir was reportedly due to the difficulty in producing the pure (RP)-diastereomer of the required precursor. However, the two currently known enzymes responsible for the initial activation step of remdesivir are each stereoselective and show differential tissue distribution. Given the ability of the COVID-19 virus to infect a wide array of tissue types, inclusion of the (RP)-diastereomer may be of clinical significance. To help overcome the challenge of obtaining the pure (RP)-diastereomer of remdesivir, we have developed a novel chemoenzymatic strategy that utilizes a stereoselective variant of the phosphotriesterase from Pseudomonas diminuta to enable the facile isolation of the pure (RP)-diastereomer of the chiral precursor for the chemical synthesis of the (RP)-diastereomer of remdesivir.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/síntese química , Monofosfato de Adenosina/síntese química , Alanina/síntese química , Betacoronavirus , Caulobacteraceae/enzimologia , Infecções por Coronavirus , Humanos , Estrutura Molecular , Pandemias , Hidrolases de Triester Fosfórico/química , Pneumonia Viral , RNA Replicase/antagonistas & inibidores , Replicação Viral/efeitos dos fármacos
15.
Int J Antimicrob Agents ; 56(3): 106118, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32738305

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic is rapidly advancing across the globe despite drastic public and personal health measures. Antivirals and nutritional supplements have been proposed as potentially useful against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus that causes COVID-19, but few have been clinically established. Lactoferrin (Lf) is a naturally occurring, non-toxic glycoprotein that is orally available as a nutritional supplement and has established in vitro antiviral efficacy against a wide range of viruses, including SARS-CoV, a closely related coronavirus to SARS-CoV-2. Furthermore, Lf possesses unique immunomodulatory and anti-inflammatory effects that may be especially relevant to the pathophysiology of severe COVID-19 cases. Here we review the underlying biological mechanisms of Lf as an antiviral and immune regulator, and propose its unique potential as a preventative and adjunct treatment for COVID-19. We hope that further research and development of Lf nutritional supplementation would establish its role for COVID-19.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antivirais/uso terapêutico , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Fatores Imunológicos/uso terapêutico , Lactoferrina/uso terapêutico , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/epidemiologia , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Proteoglicanas de Heparan Sulfato/antagonistas & inibidores , Proteoglicanas de Heparan Sulfato/metabolismo , Humanos , Interferons/agonistas , Interferons/biossíntese , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , Índice de Gravidade de Doença , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
16.
Nat Commun ; 11(1): 3910, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764693

RESUMO

SARS-CoV-2, a ß-coronavirus, has rapidly spread across the world, highlighting its high transmissibility, but the underlying morphogenesis and pathogenesis remain poorly understood. Here, we characterize the replication dynamics, cell tropism and morphogenesis of SARS-CoV-2 in organotypic human airway epithelial (HAE) cultures. SARS-CoV-2 replicates efficiently and infects both ciliated and secretory cells in HAE cultures. In comparison, HCoV-NL63 replicates to lower titers and is only detected in ciliated cells. SARS-CoV-2 shows a similar morphogenetic process as other coronaviruses but causes plaque-like cytopathic effects in HAE cultures. Cell fusion, apoptosis, destruction of epithelium integrity, cilium shrinking and beaded changes are observed in the plaque regions. Taken together, our results provide important insights into SARS-CoV-2 cell tropism, replication and morphogenesis.


Assuntos
Betacoronavirus/fisiologia , Infecções por Coronavirus/virologia , Células Epiteliais/virologia , Morfogênese/fisiologia , Pneumonia Viral/virologia , Sistema Respiratório/virologia , Betacoronavirus/patogenicidade , Linhagem Celular , Células Cultivadas , Efeito Citopatogênico Viral , Células Epiteliais/patologia , Humanos , Pandemias , Sistema Respiratório/patologia , Tropismo , Replicação Viral
17.
Drug Des Devel Ther ; 14: 3215-3222, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32821086

RESUMO

The novel coronavirus 2019 (2019-nCoV), formally named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a novel human infectious coronavirus. The disease caused by SARS-CoV-2 is named COVID-19. Development and manufacturing of specific therapeutics and vaccines to treat COVID-19 are time-consuming processes. At this time, using available conventional therapeutics along with other treatment options may be useful to fight COVID-19. In different clinical trials, efficacy of remdesivir (GS-5734) against Ebola virus has been demonstrated. Moreover, remdesivir may be an effective therapy in vitro and in animal models infected by SARS and MERS coronaviruses. Hence, the drug may be theoretically effective against SARS-CoV-2. Remdesivir is a phosphoramidate prodrug of an adenosine C-nucleoside. By entrance into respiratory epithelial cells in human, the prodrug is metabolized to a nucleoside triphosphate as the active form. The nucleoside analog inhibits the viral RNA-dependent RNA polymerase (RdRp) by competing with the usual counterpart adenosine triphosphate (ATP). The nucleoside analog is incorporated into the generating RNA strand and causes a delayed stop in the viral replication process. Knowledge about the potential efficacy of remdesivir against coronaviruses has been restricted to in vitro studies and animal models. However, information related to COVID-19 is rapidly growing. Several clinical trials are ongoing for the management of COVID-19 using remdesivir. In this study, characteristics of remdesivir and its usage for treatment of COVID-19 are reviewed based on an electronic search using PubMed and Google Scholar.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/uso terapêutico , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Monofosfato de Adenosina/farmacocinética , Monofosfato de Adenosina/farmacologia , Monofosfato de Adenosina/uso terapêutico , Alanina/farmacocinética , Alanina/farmacologia , Alanina/uso terapêutico , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Ensaios Clínicos como Assunto , Humanos , Pandemias , Replicação Viral/efeitos dos fármacos
18.
J Transl Med ; 18(1): 319, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811513

RESUMO

In less than 20 years, three deadly coronaviruses, SARS-CoV, MERS-CoV and SARS-CoV-2, have emerged in human population causing hundreds to hundreds of thousands of deaths. Other coronaviruses are causing epizootic representing a significant threat for both domestic and wild animals. Members of this viral family have the longest genome of all RNA viruses, and express up to 29 proteins establishing complex interactions with the host proteome. Deciphering these interactions is essential to identify cellular pathways hijacked by these viruses to replicate and escape innate immunity. Virus-host interactions also provide key information to select targets for antiviral drug development. Here, we have manually curated the literature to assemble a unique dataset of 1311 coronavirus-host protein-protein interactions. Functional enrichment and network-based analyses showed coronavirus connections to RNA processing and translation, DNA damage and pathogen sensing, interferon production, and metabolic pathways. In particular, this global analysis pinpointed overlooked interactions with translation modulators (GIGYF2-EIF4E2), components of the nuclear pore, proteins involved in mitochondria homeostasis (PHB, PHB2, STOML2), and methylation pathways (MAT2A/B). Finally, interactome data provided a rational for the antiviral activity of some drugs inhibiting coronaviruses replication. Altogether, this work describing the current landscape of coronavirus-host interactions provides valuable hints for understanding the pathophysiology of coronavirus infections and developing effective antiviral therapies.


Assuntos
Infecções por Coronavirus/metabolismo , Coronavirus/metabolismo , Interações Hospedeiro-Patógeno/fisiologia , Mapas de Interação de Proteínas , Proteínas Virais/metabolismo , Animais , Betacoronavirus/fisiologia , Coronavirus/química , Infecções por Coronavirus/virologia , Bases de Dados de Proteínas , Humanos , Proteínas Mitocondriais/metabolismo , Pandemias , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Fatores de Transcrição/metabolismo , Replicação Viral/genética
19.
Front Immunol ; 11: 1623, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32733488

RESUMO

Countries worldwide have confirmed a staggering number of COVID-19 cases, and it is now clear that no country is immune to the SARS-CoV-2 infection. Resource-poor countries with weaker health systems are struggling with epidemics of their own and are now in a more uncertain situation with this rapidly spreading infection. Frontline healthcare workers are succumbing to the infection in their efforts to save lives. There is an urgency to develop treatments for COVID-19, yet there is limited clinical data on the efficacy of potential drug treatments. Countries worldwide implemented a stay-at-home order to "flatten the curve" and relieve the pressure on the health system, but it is uncertain how this will unfold after the economy reopens. Trehalose, a natural glucose disaccharide, is known to impair viral function through the autophagy system. Here, we propose trehalose as a potential preventative treatment for SARS-CoV-2 infection and transmission.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/fisiologia , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Profilaxia Pós-Exposição/métodos , Profilaxia Pré-Exposição/métodos , Trealose/uso terapêutico , Adulto , Idoso , Antivirais/farmacologia , Doenças Assintomáticas , Autofagia/efeitos dos fármacos , Criança , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Humanos , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Trealose/farmacologia , Replicação Viral/efeitos dos fármacos
20.
Med Sci (Paris) ; 36(8-9): 775-782, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32755537

RESUMO

The recent emergence of a new coronavirus, SARS-CoV-2, responsible for COVID-19, is a new warning of the risk to public health represented by viral zoonoses and in particular by coronaviruses. Mainly described as being able to infect the upper and lower respiratory tract, coronaviruses can also infect the central and peripheral nervous systems as many other respiratory viruses, such as influenza or respiratory syncytial virus. Viral infections of the nervous system are a major public health concern as they can cause devastating illnesses up to death, especially when they occur in the elderly, who are more susceptible to these infections. Knowledge concerning the pathophysiology of recently emerging coronaviruses (MERS-CoV, SARS-CoV and SARS-CoV-2) and how they reach the central nervous system are very sketchy and the work in progress aims in particular to better understand their biology and the mechanisms associated with neurological damage. In this review we will discuss the current state of knowledge on the neurotropism of human coronaviruses and the associated mechanisms by developing in particular the latest data concerning SARS-CoV-2.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/complicações , Doenças do Sistema Nervoso/etiologia , Pandemias , Pneumonia Viral/complicações , Animais , Transporte Biológico , Técnicas de Laboratório Clínico , Doenças Transmissíveis Emergentes , Coronaviridae/patogenicidade , Coronaviridae/fisiologia , Coronaviridae/ultraestrutura , Infecções por Coronaviridae/complicações , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/fisiopatologia , Humanos , Sistema Nervoso/virologia , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/terapia , Doenças do Sistema Nervoso/virologia , Especificidade de Órgãos , Pneumonia Viral/diagnóstico , Pneumonia Viral/fisiopatologia , Tropismo Viral , Virulência , Replicação Viral , Zoonoses
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA