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1.
Virol J ; 18(1): 182, 2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34496903

RESUMO

BACKGROUND: Traditional medicines based on herbal extracts have been proposed as affordable treatments for patients suffering from coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Teas and drinks containing extracts of Artemisia annua and Artemisia afra have been widely used in Africa in efforts to prevent SARS-CoV-2 infection and fight COVID-19. METHODS: The plant extracts and Covid-Organics drink produced in Madagascar were tested for plaque reduction using both feline coronavirus and SARS-CoV-2 in vitro. Their cytotoxicities were also investigated. RESULTS: Several extracts as well as Covid-Organics inhibited SARS-CoV-2 and FCoV infection at concentrations that did not affect cell viability. CONCLUSIONS: Some plant extracts show inhibitory activity against FCoV and SARS-CoV-2. However, it remains unclear whether peak plasma concentrations in humans can reach levels needed to inhibit viral infection following consumption of teas or Covid-Organics. Clinical studies are required to evaluate the utility of these drinks for COVID-19 prevention or treatment of patients.


Assuntos
Antivirais/farmacologia , Artemisia/química , Extratos Vegetais/farmacologia , SARS-CoV-2/efeitos dos fármacos , Animais , Antivirais/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Coronavirus Felino/efeitos dos fármacos , Coronavirus Felino/crescimento & desenvolvimento , Extratos Vegetais/química , SARS-CoV-2/crescimento & desenvolvimento , Ensaio de Placa Viral
2.
Cells ; 10(9)2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34571822

RESUMO

As viruses are obligatory intracellular parasites, any step during their life cycle strictly depends on successful interaction with their particular host cells. In particular, their interaction with cellular membranes is of crucial importance for most steps in the viral replication cycle. Such interactions are initiated by uptake of viral particles and subsequent trafficking to intracellular compartments to access their replication compartments which provide a spatially confined environment concentrating viral and cellular components, and subsequently, employ cellular membranes for assembly and exit of viral progeny. The ability of viruses to actively modulate lipid composition such as sphingolipids (SLs) is essential for successful completion of the viral life cycle. In addition to their structural and biophysical properties of cellular membranes, some sphingolipid (SL) species are bioactive and as such, take part in cellular signaling processes involved in regulating viral replication. It is especially due to the progress made in tools to study accumulation and dynamics of SLs, which visualize their compartmentalization and identify interaction partners at a cellular level, as well as the availability of genetic knockout systems, that the role of particular SL species in the viral replication process can be analyzed and, most importantly, be explored as targets for therapeutic intervention.


Assuntos
Esfingolipídeos/metabolismo , Viroses , Transporte Biológico , Membrana Celular/química , Ceramidas/metabolismo , Sistemas de Liberação de Medicamentos , HIV/crescimento & desenvolvimento , Interações entre Hospedeiro e Microrganismos , Membranas Intracelulares/química , SARS-CoV-2/crescimento & desenvolvimento , Vírion , Replicação Viral , Vírus/crescimento & desenvolvimento
3.
Biocontrol Sci ; 26(3): 177-180, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34556620

RESUMO

Ethanol is an effective disinfectant against the novel coronavirus SARS-CoV-2. However, its effective concentration has not been shown, and we therefore analyzed the effects of different concentrations of ethanol on SARS-CoV-2. When SARS-CoV-2 was treated with varying ethanol concentrations and examined for changes in infectivity, the ethanol concentration at which 99% of the infectious titers were reduced was 24.1% (w/w) [29.3% (v/v)]. For reference, ethanol susceptibility was also examined with other envelope viruses, including influenza virus, vesicular stomatitis virus in the family Rhabdoviridae, and Newcastle disease virus in the family Paramyxoviridae, and the 99% inhibitory concentrations were found to be 28.8%(w/w) [34.8% (v/v)], 24.0% (w/w) [29.2% (v/v)], and 13.3% (w/w) [16.4% (v/v)], respectively. Some differences from SARS-CoV-2 were observed, but the differences were not significant. It was concluded that ethanol at a concentration of 30%(w/w) [36.2% (v/v)] almost completely inactivates SARS-CoV-2.


Assuntos
Desinfetantes/farmacologia , Etanol/farmacologia , SARS-CoV-2/efeitos dos fármacos , COVID-19/virologia , Desinfetantes/análise , Etanol/análise , Humanos , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/fisiologia , Inativação de Vírus/efeitos dos fármacos , Vírus/efeitos dos fármacos , Vírus/crescimento & desenvolvimento
4.
J Toxicol Sci ; 46(9): 425-435, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34470994

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). SARS-CoV-2 enters host cells by binding with the receptor angiotensin-converting enzyme 2 (ACE2). While ACE2 is expressed in multiple cell types, it has been implicated in the clinical progression of COVID-19 as an entry point for SARS-CoV-2 into respiratory cells. Human respiratory cells, such as airway and alveolar epithelial type II (ATII) cells, are considered essential for COVID-19 research; however, primary human respiratory cells are difficult to obtain. In the present study, we generated ATII and club cells from human induced pluripotent stem cells (hiPSCs) for SARS-CoV-2 infection and drug testing. The differentiated cells expressed ATII markers (SFTPB, SFTPC, ABCA3, SLC34A2) or club cell markers (SCGB1A1 and SCGB3A2). Differentiated cells, which express ACE2 and TMPRSS2, were infected with SARS-CoV-2. Remdesivir treatment decreased intracellular SARS-CoV-2 viral replication and, furthermore, treatment with bleomycin showed cytotoxicity in a concentration-dependent manner. These data suggest that hiPSC-derived AT2 and club cells provide a useful in vitro model for drug development.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Células Epiteliais Alveolares/efeitos dos fármacos , Antivirais/farmacologia , Bleomicina/toxicidade , Diferenciação Celular , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Testes de Toxicidade , Monofosfato de Adenosina/farmacologia , Alanina/farmacologia , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/patologia , Células Epiteliais Alveolares/virologia , COVID-19/tratamento farmacológico , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Células-Tronco Pluripotentes Induzidas/virologia , Fenótipo , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/patogenicidade , Replicação Viral/efeitos dos fármacos
5.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34413211

RESUMO

The global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the associated disease COVID-19, requires therapeutic interventions that can be rapidly identified and translated to clinical care. Traditional drug discovery methods have a >90% failure rate and can take 10 to 15 y from target identification to clinical use. In contrast, drug repurposing can significantly accelerate translation. We developed a quantitative high-throughput screen to identify efficacious agents against SARS-CoV-2. From a library of 1,425 US Food and Drug Administration (FDA)-approved compounds and clinical candidates, we identified 17 hits that inhibited SARS-CoV-2 infection and analyzed their antiviral activity across multiple cell lines, including lymph node carcinoma of the prostate (LNCaP) cells and a physiologically relevant model of alveolar epithelial type 2 cells (iAEC2s). Additionally, we found that inhibitors of the Ras/Raf/MEK/ERK signaling pathway exacerbate SARS-CoV-2 infection in vitro. Notably, we discovered that lactoferrin, a glycoprotein found in secretory fluids including mammalian milk, inhibits SARS-CoV-2 infection in the nanomolar range in all cell models with multiple modes of action, including blockage of virus attachment to cellular heparan sulfate and enhancement of interferon responses. Given its safety profile, lactoferrin is a readily translatable therapeutic option for the management of COVID-19.


Assuntos
Antivirais/farmacologia , Fatores Imunológicos/farmacologia , Lactoferrina/farmacologia , SARS-CoV-2/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , COVID-19/tratamento farmacológico , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Células CACO-2 , Linhagem Celular Tumoral , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Descoberta de Drogas , Reposicionamento de Medicamentos/métodos , Células Epiteliais , Heparitina Sulfato/antagonistas & inibidores , Heparitina Sulfato/imunologia , Heparitina Sulfato/metabolismo , Hepatócitos , Ensaios de Triagem em Larga Escala , Humanos , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/patogenicidade , Células Vero
7.
Biochem Biophys Res Commun ; 575: 36-41, 2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34455219

RESUMO

Air spaces and material surfaces in a pathogen-contaminated environment can often be a source of infection to humans, and disinfection has become a common intervention focused on reducing the contamination levels. In this study, we examined the efficacy of SAIW, a unique electrolyzed water with chlorine-free, high pH, high concentration of dissolved hydrogen, and low oxygen reduction potential, for the inactivation of several viruses and bacteria. Infectivity assays revealed that initial viral titers of enveloped and non-enveloped viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, herpes simplex virus type 1, human coronavirus, feline calicivirus, and canine parvovirus, were reduced by 2.9- to 5.5-log10 within 30 s of SAIW exposure. Similarly, the culturability of three Gram-negative bacteria (Escherichia coli, Salmonella, and Legionella) dropped down by 1.9- to 4.9-log10 within 30 s of SAIW treatment. Mechanistically, treatment with SAIW was found to significantly decrease the binding and subsequent entry efficiencies of SARS-CoV-2 on Vero cells. Finally, we showed that this chlorine-free electrolytic ion water had no acute inhalation toxicity in mice, demonstrating that SAIW holds promise for a safer antiviral and antibacterial disinfectant.


Assuntos
Anti-Infecciosos/farmacologia , Desinfetantes/farmacologia , Desinfecção/métodos , SARS-CoV-2/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacos , Água/farmacologia , Animais , Calicivirus Felino/efeitos dos fármacos , Calicivirus Felino/crescimento & desenvolvimento , Chlorocebus aethiops , Contagem de Colônia Microbiana , Eletrólise , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/crescimento & desenvolvimento , Humanos , Concentração de Íons de Hidrogênio , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/crescimento & desenvolvimento , Legionella/efeitos dos fármacos , Legionella/crescimento & desenvolvimento , Camundongos , Parvovirus Canino/efeitos dos fármacos , Parvovirus Canino/crescimento & desenvolvimento , SARS-CoV-2/crescimento & desenvolvimento , Salmonella/efeitos dos fármacos , Salmonella/crescimento & desenvolvimento , Pele/efeitos dos fármacos , Células Vero , Carga Viral
8.
Nature ; 597(7878): 703-708, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34428777

RESUMO

SARS-CoV-2 infections have surged across the globe in recent months, concomitant with considerable viral evolution1-3. Extensive mutations in the spike protein may threaten the efficacy of vaccines and therapeutic monoclonal antibodies4. Two signature spike mutations of concern are E484K, which has a crucial role in the loss of neutralizing activity of antibodies, and N501Y, a driver of rapid worldwide transmission of the B.1.1.7 lineage. Here we report the emergence of the variant lineage B.1.526 (also known as the Iota variant5), which contains E484K, and its rise to dominance in New York City in early 2021. This variant is partially or completely resistant to two therapeutic monoclonal antibodies that are in clinical use and is less susceptible to neutralization by plasma from individuals who had recovered from SARS-CoV-2 infection or serum from vaccinated individuals, posing a modest antigenic challenge. The presence of the B.1.526 lineage has now been reported in all 50 states in the United States and in many other countries. B.1.526 rapidly replaced earlier lineages in New York, with an estimated transmission advantage of 35%. These transmission dynamics, together with the relative antibody resistance of its E484K sub-lineage, are likely to have contributed to the sharp rise and rapid spread of B.1.526. Although SARS-CoV-2 B.1.526 initially outpaced B.1.1.7 in the region, its growth subsequently slowed concurrently with the rise of B.1.1.7 and ensuing variants.


Assuntos
COVID-19/virologia , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Humanos , Mutação , New York/epidemiologia , Filogenia , Filogeografia , Prevalência , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Estados Unidos/epidemiologia
9.
Viruses ; 13(8)2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34452302

RESUMO

Transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs through respiratory droplets passed directly from person to person or indirectly through fomites, such as common use surfaces or objects. The aim of this study was to determine the virucidal efficacy of blue LED (405 nm) and far-UVC (222 nm) light in comparison to standard UVC (254 nm) irradiation for the inactivation of feline infectious peritonitis virus (FIPV) on different matrices as a model for SARS-CoV-2. Wet or dried FIPV on stainless steel, plastic, or paper discs, in the presence or absence of artificial saliva, were exposed to various wavelengths of light for different time periods (1-90 min). Dual activity of blue LED and far-UVC lights were virucidal for most wet and dried FIPV within 4 to 16 min on all matrices. Individual action of blue LED and far-UVC lights were virucidal for wet FIPV but required longer irradiation times (8-90 min) to reach a 4-log reduction. In comparison, LED (265 nm) and germicidal UVC (254 nm) were virucidal on almost all matrices for both wet and dried FIPV within 1 min exposure. UVC was more effective for the disinfection of surfaces as compared to blue LED and far-UVC individually or together. However, dual action of blue LED and far-UVC was virucidal. This combination of lights could be used as a safer alternative to traditional UVC.


Assuntos
COVID-19/virologia , Coronavirus Felino/efeitos da radiação , Desinfecção/métodos , SARS-CoV-2/efeitos da radiação , Animais , COVID-19/prevenção & controle , Gatos , Infecções por Coronavirus/virologia , Coronavirus Felino/crescimento & desenvolvimento , Coronavirus Felino/fisiologia , Desinfecção/instrumentação , Humanos , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/fisiologia , Raios Ultravioleta , Inativação de Vírus/efeitos da radiação
11.
Front Immunol ; 12: 697329, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34386007

RESUMO

Various neurological symptoms have been associated to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection including headache, fever, anosmia, ageusia, but also, encephalitis, Guillain-Barre syndrome and ischemic stroke. Responsible for the current coronavirus disease (COVID-19) pandemic, SARS-CoV-2 may access and affect the central nervous system (CNS) by several pathways such as axonal retrograde transport or through interaction with the blood-brain barrier (BBB) or blood-cerebrospinal fluid (CSF) barrier. Here, we explored the molecular and cellular effects of direct SARS-CoV-2 infection of human BBB cells. We observed low replication of SARS-CoV-2 that was accompanied by very moderate inflammatory response. Using a human in vitro BBB model, we also described low replication levels without strong inflammatory response or modulation of endothelium integrity. Finally, using serum samples from COVID-19 patients, we highlighted strong concentrations of pro-inflammatory factors that did not perturb BBB integrity after short term exposure. Altogether, our results show that the main mechanism of brain access following SARS-CoV-2 infection does not seem to be directed by brain infection through endothelial cells.


Assuntos
Barreira Hematoencefálica/virologia , Encéfalo/virologia , Células Endoteliais/virologia , SARS-CoV-2/crescimento & desenvolvimento , Replicação Viral/fisiologia , Animais , COVID-19/patologia , Linhagem Celular Tumoral , Chlorocebus aethiops , Humanos , Células Vero
12.
Signal Transduct Target Ther ; 6(1): 300, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381015

RESUMO

Elderly people and patients with comorbidities are at higher risk of COVID-19 infection, resulting in severe complications and high mortality. However, the underlying mechanisms are unclear. In this study, we investigate whether miRNAs in serum exosomes can exert antiviral functions and affect the response to COVID-19 in the elderly and people with diabetes. First, we identified four miRNAs (miR-7-5p, miR-24-3p, miR-145-5p and miR-223-3p) through high-throughput sequencing and quantitative real-time PCR analysis, that are remarkably decreased in the elderly and diabetic groups. We further demonstrated that these miRNAs, either in the exosome or in the free form, can directly inhibit S protein expression and SARS-CoV-2 replication. Serum exosomes from young people can inhibit SARS-CoV-2 replication and S protein expression, while the inhibitory effect is markedly decreased in the elderly and diabetic patients. Moreover, three out of the four circulating miRNAs are significantly increased in the serum of healthy volunteers after 8-weeks' continuous physical exercise. Serum exosomes isolated from these volunteers also showed stronger inhibitory effects on S protein expression and SARS-CoV-2 replication. Our study demonstrates for the first time that circulating exosomal miRNAs can directly inhibit SARS-CoV-2 replication and may provide a possible explanation for the difference in response to COVID-19 between young people and the elderly or people with comorbidities.


Assuntos
COVID-19/genética , Diabetes Mellitus/genética , MicroRNAs/genética , Glicoproteína da Espícula de Coronavírus/genética , Adulto , Fatores Etários , Idoso , COVID-19/sangue , COVID-19/patologia , COVID-19/virologia , China , MicroRNA Circulante/sangue , MicroRNA Circulante/genética , Estudos de Coortes , Diabetes Mellitus/sangue , Diabetes Mellitus/patologia , Diabetes Mellitus/virologia , Exercício Físico , Exossomos/genética , Exossomos/metabolismo , Exossomos/virologia , Feminino , Regulação da Expressão Gênica , Células HEK293 , Interações Hospedeiro-Patógeno/genética , Humanos , Masculino , MicroRNAs/sangue , Pessoa de Meia-Idade , SARS-CoV-2/genética , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/sangue , Replicação Viral
13.
Biotechnol Bioeng ; 118(10): 3996-4013, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34219217

RESUMO

Seasonal influenza epidemics occur both in northern and southern hemispheres every year. Despite the differences in influenza virus surface antigens and virulence of seasonal subtypes, manufacturers are well-adapted to respond to this periodical vaccine demand. Due to decades of influenza virus research, the development of new influenza vaccines is relatively straight forward. In similarity with the ongoing coronavirus disease 2019 pandemic, vaccine manufacturing is a major bottleneck for a rapid supply of the billions of doses required worldwide. In particular, egg-based vaccine production would be difficult to schedule and shortages of other egg-based vaccines with high demands also have to be anticipated. Cell culture-based production systems enable the manufacturing of large amounts of vaccines within a short time frame and expand significantly our options to respond to pandemics and emerging viral diseases. In this study, we present an integrated process for the production of inactivated influenza A virus vaccines based on a Madin-Darby Canine Kidney (MDCK) suspension cell line cultivated in a chemically defined medium. Very high titers of 3.6 log10 (HAU/100 µl) were achieved using fast-growing MDCK cells at concentrations up to 9.5 × 106 cells/ml infected with influenza A/PR/8/34 H1N1 virus in 1 L stirred tank bioreactors. A combination of membrane-based steric-exclusion chromatography followed by pseudo-affinity chromatography with a sulfated cellulose membrane adsorber enabled full recovery for the virus capture step and up to 80% recovery for the virus polishing step. Purified virus particles showed a homogenous size distribution with a mean diameter of 80 nm. Based on a monovalent dose of 15 µg hemagglutinin (single-radial immunodiffusion assay), the level of total protein and host cell DNA was 58 µg and 10 ng, respectively. Furthermore, all process steps can be fully scaled up to industrial quantities for commercial manufacturing of either seasonal or pandemic influenza virus vaccines. Fast production of up to 300 vaccine doses per liter within 4-5 days makes this process competitive not only to other cell-based processes but to egg-based processes as well.


Assuntos
COVID-19 , Técnicas de Cultura de Células , Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Vacinas contra Influenza/metabolismo , SARS-CoV-2/crescimento & desenvolvimento , Animais , Cães , Células Madin Darby de Rim Canino
15.
mBio ; 12(4): e0106721, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34225491

RESUMO

The coronavirus disease 2019 pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an ongoing global public crisis. Although viral RNA modification has been reported based on the transcriptome architecture, the types and functions of RNA modification are still unknown. In this study, we evaluated the roles of RNA N6-methyladenosine (m6A) modification in SARS-CoV-2. Our methylated RNA immunoprecipitation sequencing (MeRIP-Seq) and Nanopore direct RNA sequencing (DRS) analysis showed that SARS-CoV-2 RNA contained m6A modification. Moreover, SARS-CoV-2 infection not only increased the expression of methyltransferase-like 3 (METTL3) but also altered its distribution. Modification of METTL3 expression by short hairpin RNA or plasmid transfection for knockdown or overexpression, respectively, affected viral replication. Furthermore, the viral key protein RdRp interacted with METTL3, and METTL3 was distributed in both the nucleus and cytoplasm in the presence of RdRp. RdRp appeared to modulate the sumoylation and ubiquitination of METTL3 via an unknown mechanism. Taken together, our findings demonstrated that the host m6A modification complex interacted with viral proteins to modulate SARS-CoV-2 replication. IMPORTANCE Internal chemical modifications of viral RNA play key roles in the regulation of viral replication and gene expression. Although potential internal modifications have been reported in SARS-CoV-2 RNA, the function of the SARS-CoV-2 N6-methyladenosine (m6A) modification in the viral life cycle is unclear. In the current study, we demonstrated that SARS-CoV-2 RNA underwent m6A modification by host m6A machinery. SARS-CoV-2 infection altered the expression pattern of methyltransferases and demethylases, while the expression level of methyltransferase-like 3 (METTL3) and fat mass and obesity-associated protein (FTO) was linked to the viral replication. Further study showed that METTL3 interacted with viral RNA polymerase RNA-dependent RNA polymerase (RdRp), which influenced not only the distribution but also the posttranslational modification of METTL3. Our study provided evidence that host m6A components interacted with viral proteins to modulate viral replication.


Assuntos
Adenosina/análogos & derivados , Metiltransferases/genética , Metiltransferases/metabolismo , SARS-CoV-2/crescimento & desenvolvimento , Replicação Viral/genética , Adenosina/química , Adenosina/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , COVID-19/patologia , Regulação da Expressão Gênica/genética , Humanos , Metilação , Processamento de Proteína Pós-Traducional/fisiologia , RNA Viral/química , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , SARS-CoV-2/genética
16.
Microbiol Spectr ; 9(1): e0033321, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34287031

RESUMO

We studied the stability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) under different simulated outdoor conditions by changing the temperature (20°C and 35°C), the illuminance (darkness, 10 klx, and 56 klx), and/or the cleanness of the surfaces at 50% relative humidity (RH). In darkness, the loss of viability of the virus on stainless steel is temperature dependent, but this is hidden by the effect of the sunlight from the first minutes of exposure. The virus shows a sensitivity to sunlight proportional to the illuminance intensity of the sunlight. The presence of interfering substances has a moderate effect on virus viability even with an elevated illuminance. Thus, SARS-CoV-2 is rapidly inactivated by simulated sunlight in the presence or absence of high levels of interfering substances at 20°C or 35°C and 50% relative humidity. IMPORTANCE Clinical matrix contains high levels of interfering substances. This study is the first to reveal that the presence of high levels of interfering substances had little impact on the persistence of SARS-CoV-2 on stainless steel following exposure to simulated sunlight. Thus, SARS-CoV-2 should be rapidly inactivated in outdoor environments in the presence or absence of interfering substances. Our results indicate that transmission of SARS-CoV-2 is unlikely to occur through outdoor surfaces, dependent on illuminance intensity. Moreover, most studies are interested in lineage S of SARS-CoV-2. In our experiments, we studied the stability of L-type strains, which comprise the majority of strains isolated from worldwide patients. Nevertheless, the effect of sunlight seems to be similar regardless of the strain studied, suggesting that the greater spread of certain variants is not correlated with better survival in outdoor conditions.


Assuntos
Viabilidade Microbiana/efeitos da radiação , SARS-CoV-2/efeitos da radiação , Luz Solar , Inativação de Vírus/efeitos da radiação , COVID-19/prevenção & controle , COVID-19/transmissão , Descontaminação , Humanos , Cinética , SARS-CoV-2/crescimento & desenvolvimento , Propriedades de Superfície , Temperatura
17.
Emerg Microbes Infect ; 10(1): 1519-1529, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34278967

RESUMO

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutated continuously and newly emerging variants escape from antibody-mediated neutralization raised great concern. S protein is heavily glycosylated and the glycosylation sites are relatively conserved, thus glycans on S protein surface could be a target for the development of anti-SARS-CoV-2 strategies against variants. Here, we collected 12 plant-derived lectins with different carbohydrate specificity and evaluated their anti-SARS-CoV-2 activity against mutant strains and epidemic variants using a pseudovirus-based neutralization assay. The Lens culinaris-derived lentil lectin which specifically bind to oligomannose-type glycans and GlcNAc at the non-reducing end terminus showed most potent and broad antiviral activity against a panel of mutant strains and variants, including the artificial mutants at N-/O-linked glycosylation site, natural existed amino acid mutants, as well as the epidemic variants B.1.1.7, B.1.351, and P.1. Lentil lectin also showed antiviral activity against SARS-CoV and MERS-CoV. We found lentil lectin could block the binding of ACE2 to S trimer and inhibit SARS-CoV-2 at the early steps of infection. Using structural information and determined N-glycan profile of S trimer, taking together with the carbohydrate specificity of lentil lectin, we provide a basis for the observed broad spectrum anti-SARS-CoV-2 activity. Lentil lectin showed weak haemagglutination activity at 1 mg/mL and no cytotoxicity activity, and no weight loss was found in single injection mouse experiment. This report provides the first evidence that lentil lectin strongly inhibit infection of SARS-COV-2 variants, which should provide valuable insights for developing future anti-SARS-CoV-2 strategies.


Assuntos
Antivirais/farmacologia , Lens (Planta)/química , Extratos Vegetais/farmacologia , Lectinas de Plantas/farmacologia , SARS-CoV-2/efeitos dos fármacos , Animais , Antivirais/química , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/química , Lectinas de Plantas/química , SARS-CoV-2/crescimento & desenvolvimento , Sementes/química
18.
JAMA Netw Open ; 4(7): e2116543, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34287634

RESUMO

Importance: Detailed analysis of infection rates paired with behavioral and employee-reported risk factors is vital to understanding how transmission of SARS-CoV-2 infection may be exacerbated or mitigated in the workplace. Institutions of higher education are heterogeneous work units that supported continued in-person employment during the COVID-19 pandemic, providing a test site for occupational health evaluation. Objective: To evaluate the association between self-reported protective behaviors and prevalence of SARS-CoV-2 infection among essential in-person employees during the first 6 months of the COVID-19 pandemic in the US. Design, Setting, and Participants: This cross-sectional study was conducted from July 13 to September 2, 2020, at an institution of higher education in Fort Collins, Colorado. Employees 18 years or older without symptoms of COVID-19 who identified as essential in-person workers during the first 6 months of the pandemic were included. Participants completed a survey, and blood and nasal swab samples were collected to assess active SARS-CoV-2 infection via quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and past infection by serologic testing. Exposure: Self-reported practice of protective behaviors against COVID-19 according to public health guidelines provided to employees. Main Outcomes and Measures: Prevalence of current SARS-CoV-2 infection detected by qRT-PCR or previous SARS-CoV-2 infection detected by an IgG SARS-CoV-2 testing platform. The frequency of protective behavior practices and essential workers' concerns regarding contracting COVID-19 and exposing others were measured based on survey responses. Results: Among 508 participants (305 [60.0%] women, 451 [88.8%] non-Hispanic White individuals; mean [SD] age, 41.1 [12.5] years), there were no qRT-PCR positive test results, and only 2 participants (0.4%) had seroreactive IgG antibodies. Handwashing and mask wearing were reported frequently both at work (480 [94.7%] and 496 [97.8%] participants, respectively) and outside work (465 [91.5%] and 481 [94.7%] participants, respectively). Social distancing was reported less frequently at work (403 [79.5%]) than outside work (465 [91.5%]) (P < .001). Participants were more highly motivated to avoid exposures because of concern about spreading the infection to others (419 [83.0%]) than for personal protection (319 [63.2%]) (P < .001). Conclusions and Relevance: In this cross-sectional study of essential workers at an institution of higher education, when employees reported compliance with public health practices both at and outside work, they were able to operate safely in their work environment during the COVID-19 pandemic.


Assuntos
COVID-19 , Pandemias , Saúde Pública , SARS-CoV-2 , Comportamento Social , Universidades , Local de Trabalho , Adulto , COVID-19/sangue , COVID-19/prevenção & controle , COVID-19/transmissão , COVID-19/virologia , Teste para COVID-19 , Colorado , Controle de Doenças Transmissíveis , Estudos Transversais , Feminino , Guias como Assunto , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Saúde do Trabalhador , Reação em Cadeia da Polimerase , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/imunologia , Autorrelato
19.
PLoS Biol ; 19(7): e3001333, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34252080

RESUMO

SARS-CoV-2 infections are characterized by viral proliferation and clearance phases and can be followed by low-level persistent viral RNA shedding. The dynamics of viral RNA concentration, particularly in the early stages of infection, can inform clinical measures and interventions such as test-based screening. We used prospective longitudinal quantitative reverse transcription PCR testing to measure the viral RNA trajectories for 68 individuals during the resumption of the 2019-2020 National Basketball Association season. For 46 individuals with acute infections, we inferred the peak viral concentration and the duration of the viral proliferation and clearance phases. According to our mathematical model, we found that viral RNA concentrations peaked an average of 3.3 days (95% credible interval [CI] 2.5, 4.2) after first possible detectability at a cycle threshold value of 22.3 (95% CI 20.5, 23.9). The viral clearance phase lasted longer for symptomatic individuals (10.9 days [95% CI 7.9, 14.4]) than for asymptomatic individuals (7.8 days [95% CI 6.1, 9.7]). A second test within 2 days after an initial positive PCR test substantially improves certainty about a patient's infection stage. The effective sensitivity of a test intended to identify infectious individuals declines substantially with test turnaround time. These findings indicate that SARS-CoV-2 viral concentrations peak rapidly regardless of symptoms. Sequential tests can help reveal a patient's progress through infection stages. Frequent, rapid-turnaround testing is needed to effectively screen individuals before they become infectious.


Assuntos
Teste de Ácido Nucleico para COVID-19/estatística & dados numéricos , COVID-19/diagnóstico , RNA Viral/genética , SARS-CoV-2/genética , Replicação Viral/genética , Eliminação de Partículas Virais/genética , Adulto , Atletas , Basquetebol , COVID-19/epidemiologia , COVID-19/patologia , COVID-19/virologia , Convalescença , Humanos , Masculino , Estudos Prospectivos , Saúde Pública/métodos , SARS-CoV-2/crescimento & desenvolvimento , Índice de Gravidade de Doença , Estados Unidos/epidemiologia
20.
Biochem J ; 478(13): 2465-2479, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34198324

RESUMO

SARS-CoV-2 is responsible for COVID-19, a human disease that has caused over 2 million deaths, stretched health systems to near-breaking point and endangered economies of countries and families around the world. Antiviral treatments to combat COVID-19 are currently lacking. Remdesivir, the only antiviral drug approved for the treatment of COVID-19, can affect disease severity, but better treatments are needed. SARS-CoV-2 encodes 16 non-structural proteins (nsp) that possess different enzymatic activities with important roles in viral genome replication, transcription and host immune evasion. One key aspect of host immune evasion is performed by the uridine-directed endoribonuclease activity of nsp15. Here we describe the expression and purification of nsp15 recombinant protein. We have developed biochemical assays to follow its activity, and we have found evidence for allosteric behaviour. We screened a custom chemical library of over 5000 compounds to identify nsp15 endoribonuclease inhibitors, and we identified and validated NSC95397 as an inhibitor of nsp15 endoribonuclease in vitro. Although NSC95397 did not inhibit SARS-CoV-2 growth in VERO E6 cells, further studies will be required to determine the effect of nsp15 inhibition on host immune evasion.


Assuntos
Antivirais/química , Antivirais/farmacologia , Avaliação Pré-Clínica de Medicamentos , Endorribonucleases/antagonistas & inibidores , SARS-CoV-2/enzimologia , Bibliotecas de Moléculas Pequenas/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Regulação Alostérica , Animais , Chlorocebus aethiops , Endorribonucleases/isolamento & purificação , Endorribonucleases/metabolismo , Ensaios Enzimáticos , Fluorescência , Ensaios de Triagem em Larga Escala , Técnicas In Vitro , Cinética , Naftoquinonas/farmacologia , Reprodutibilidade dos Testes , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/crescimento & desenvolvimento , Bibliotecas de Moléculas Pequenas/química , Soluções , Células Vero , Proteínas não Estruturais Virais/isolamento & purificação , Proteínas não Estruturais Virais/metabolismo
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