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1.
Food Chem ; 334: 127508, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711265

RESUMO

Quercetin, a potential polyphenolic which possesses several biological effects. The influenza virus polymerase basic 2 (PB2) subunit of RNA polymerase responsible for replication, degree of virus conservation and active target site for designing specific antivirals. The quercetin derivatives downloaded from PubChem were screened using PyRX software configured with Vina Wizard, targeted on cap-binding site of the PB2 of influenza viral RNA polymerase. Among the PubChem library (total 97,585,747 compounds), 410 quercetin derivatives were screened using molecular docking (affinity: <-9.0 kcal) for their drug-likeness and in vitro cytopathic effect by Sulforhodamine B (SRB) assay. Among all quercetin derivatives, quercetin 3'-glucuronide (Q3G) showed strongest binding affinity towards cap-binding site of the PB2 subunit with -9.6 kcal of binding affinity and 0.00054 mM of Ki value, while quercetin 3'-glucuronide (Q7G) was presented highest anti-influenza activity with 2.10 ± 0.05 of IC50 on influenza A/PR/8/34 virus and non-cytotoxic effect as CC50 > 100 µg/mL.


Assuntos
Antivirais/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Quercetina/análogos & derivados , Animais , Antivirais/química , Antivirais/metabolismo , Sítios de Ligação , Sobrevivência Celular/efeitos dos fármacos , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/metabolismo , Cães , Humanos , Vírus da Influenza A/enzimologia , Influenzavirus B/efeitos dos fármacos , Células Madin Darby de Rim Canino , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Quercetina/química , Quercetina/metabolismo , Quercetina/farmacologia , Termodinâmica
2.
Cell Rep ; 33(5): 108345, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33147460

RESUMO

Bat cells and tissue have elevated basal expression levels of antiviral genes commonly associated with interferon alpha (IFNα) signaling. Here, we show Interferon Regulatory Factor 1 (IRF1), 3, and 7 levels are elevated in most bat tissues and that, basally, IRFs contribute to the expression of type I IFN ligands and high expression of interferon regulated genes (IRGs). CRISPR knockout (KO) of IRF 1/3/7 in cells reveals distinct subsets of genes affected by each IRF in an IFN-ligand signaling-dependent and largely independent manner. As the master regulators of innate immunity, the IRFs control the kinetics and maintenance of the IRG response and play essential roles in response to influenza A virus (IAV), herpes simplex virus 1 (HSV-1), Melaka virus/Pteropine orthoreovirus 3 Melaka (PRV3M), and Middle East respiratory syndrome-related coronavirus (MERS-CoV) infection. With its differential expression in bats compared to that in humans, this highlights a critical role for basal IRF expression in viral responses and potentially immune cell development in bats with relevance for IRF function in human biology.


Assuntos
Quirópteros/imunologia , Regulação da Expressão Gênica/imunologia , Fator Regulador 1 de Interferon/imunologia , Fator Regulador 7 de Interferon/imunologia , Viroses/imunologia , Animais , Herpesvirus Humano 1/imunologia , Vírus da Influenza A/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Orthoreovirus/imunologia
3.
Washington, D.C.; OPS; 2020-11-11.
em Espanhol | PAHO-IRIS | ID: phr-53014

RESUMO

Las vacunas salvan entre 2 y 3 millones de vidas cada año y protegen a toda la población contra más de una docena de enfermedades potencialmente mortales. Gracias a la vacunación se erradicó la viruela en el año 1980 y estamos en vías de erradicar la poliomielitis. No obstante, en los últimos años ha habido un aumento en los casos de sarampión, una de las enfermedades conocidas más contagiosas. Por esta razón es necesario alcanzar una cobertura de vacunación de 95% o más, lo que constituye un gran desafío técnico y de comunicación para el personal de salud. Los estudios demuestran que informar sobre la calidad, la seguridad, la eficacia y la oferta de las vacunas no es suficiente para lograr cambios de conducta frente a la vacunación y que, en general, no aumenta su cobertura. Por este motivo, es necesario comprender las razones que llevan a las personas a no vacunarse o a no vacunar a sus hijos, con vistas a iniciar un diálogo bidireccional basado en el respeto que redunde en mensajes mejores y más eficaces. En este contexto, las presentes orientaciones tienen como objetivo principal facilitar a los equipos de salud herramientas que sirvan de apoyo para la comunicación efectiva entre el personal de salud y la población general, con miras a lograr el objetivo de fortalecer, mantener o recuperar la confianza en las vacunas y en los programas de inmunización en la Región de las Américas.


Assuntos
Imunização , Vacinas , Vacinação , Cuidadores , Família , Infecções por Coronavirus , Coronavirus , Infecções por Coronavirus , Vacina Quadrivalente Recombinante contra HPV tipos 6, 11, 16, 18 , Papiloma , Sarampo , Vacinas contra Influenza , Vírus da Influenza A , Vírus da Influenza B , Influenzavirus C , Vacina contra Sarampo-Caxumba-Rubéola
4.
Nat Commun ; 11(1): 5511, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33139731

RESUMO

Parallel molecular evolution and adaptation are important phenomena commonly observed in viruses. Here, we exploit parallel molecular evolution to understand virulence evolution in avian influenza viruses (AIV). Highly-pathogenic AIVs evolve independently from low-pathogenic ancestors via acquisition of polybasic cleavage sites. Why some AIV lineages but not others evolve in this way is unknown. We hypothesise that the parallel emergence of highly-pathogenic AIV may be facilitated by permissive or compensatory mutations occurring across the viral genome. We combine phylogenetic, statistical and structural approaches to discover parallel mutations in AIV genomes associated with the highly-pathogenic phenotype. Parallel mutations were screened using a statistical test of mutation-phenotype association and further evaluated in the contexts of positive selection and protein structure. Our resulting mutational panel may help to reveal new links between virulence evolution and other traits, and raises the possibility of predicting aspects of AIV evolution.


Assuntos
Evolução Molecular , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Influenza Humana/virologia , Virulência/genética , Animais , Sequência de Bases/genética , Aves/virologia , Conjuntos de Dados como Assunto , Genoma Viral/genética , Humanos , Vírus da Influenza A/genética , Influenza Aviária/transmissão , Influenza Humana/transmissão , Mutação , Filogenia , Estabilidade Proteica , Seleção Genética , Alinhamento de Sequência , Proteínas Virais/genética
6.
Biomed Environ Sci ; 33(9): 670-679, 2020 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-33106212

RESUMO

Objective: In China, 24 cases of human infection with highly pathogenic avian influenza (HPAI) H5N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5N6 candidate vaccine viruses (CVVs). Methods: In accordance with the World Health Organization (WHO) recommendations, we constructed two reassortant viruses using reverse genetics (RG) technology to match the two different epidemic H5N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo. Results: The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs. Conclusion: We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics, which may aid in our preparedness for a potential H5N6 pandemic.


Assuntos
Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Pandemias/prevenção & controle , Animais , Aves , China , Humanos
7.
Front Endocrinol (Lausanne) ; 11: 556962, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33123087

RESUMO

From the beginning of 2020, the governments and the health systems around the world are tackling infections and fatalities caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) resulting in the coronavirus disease 2019 (COVID-19). This virus pandemic has turned more complicated as individuals with co-morbidities like diabetes, cardiovascular conditions and obesity are at a high risk of acquiring infection and suffering from a more severe course of disease. Prolonged viral infection and obesity are independently known to lower the immune response and a combination can thus result in a "cytokine storm" and a substantial weakening of the immune system. With the rise in obesity cases globally, the chances that obese individuals will acquire infection and need hospitalization are heightened. In this review, we discuss why obesity, a low-grade chronic inflammation, contributes toward the increased severity in COVID-19 patients. We suggest that increased inflammation, activation of renin-angiotensin-aldosterone system, elevated adipokines and higher ectopic fat may be the factors contributing to the disease severity, in particular deteriorating the cardiovascular and lung function, in obese individuals. We look at the many lessons learnt from the 2009 H1N1 influenza A pandemic and relate it to the very little but fast incoming information that is available from the SARS-CoV-2 infected individuals with overweight and obesity.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Inflamação/fisiopatologia , Vírus da Influenza A/isolamento & purificação , Influenza Humana/epidemiologia , Obesidade/fisiopatologia , Pneumonia Viral/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Humanos , Influenza Humana/imunologia , Influenza Humana/virologia , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia
8.
J Breath Res ; 15(1): 011001, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-33089824

RESUMO

Infectious pathogens are a global issue. Global air travel offers an easy and fast opportunity not only for people but also for infectious diseases to spread around the world within a few days. Also, large public events facilitate increasing infection numbers. Therefore, rapid on-site screening for infected people is urgently needed. Due to the small size and easy handling, ion mobility spectrometry coupled with a multicapillary column (MCC-IMS) is a very promising, sensitive method for the on-site identification of infectious pathogens based on scents, representing volatile organic compounds (VOCs). The purpose of this study was to prospectively assess whether identification of Influenza-A-infection based on VOCs by MCC-IMS is possible in breath. Nasal breath was investigated in 24 consecutive persons with and without Influenza-A-infection by MCC-IMS. In 14 Influenza-A-infected patients, infection was proven by PCR of nasopharyngeal swabs. Four healthy staff members and six patients with negative PCR result served as controls. For picking up relevant VOCs in MCC-IMS spectra, software based on cluster analysis followed by multivariate statistical analysis was applied. With only four VOCs canonical discriminant analysis was able to distinguish Influenza-A-infected patients from those not infected with 100% sensitivity and 100% specificity. This present proof-of-concept-study yields encouraging results showing a rapid diagnosis of viral infections in nasal breath within 5 min by MCC-IMS. The next step is to validate the results with a greater number of patients with Influenza-A-infection as well as other viral diseases, especially COVID-19. Registration number at ClinicalTrials.gov NCT04282135.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Vírus da Influenza A/isolamento & purificação , Influenza Humana/diagnóstico , Pneumonia Viral/diagnóstico , Idoso , Testes Respiratórios , Infecções por Coronavirus/complicações , Análise Discriminante , Feminino , Humanos , Influenza Humana/complicações , Espectrometria de Mobilidade Iônica , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/complicações , Estudos Prospectivos , Sensibilidade e Especificidade
9.
Bol Med Hosp Infant Mex ; 77(5): 262-273, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33064680

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Alphainfluenzavirus are RNA viruses that cause coronavirus disease-19 and influenza, respectively. Both viruses infect the respiratory tract, show similar symptoms, and use surface proteins to infect the host. Influenza requires hemagglutinin and neuraminidase to infect, whereas SARS-CoV-2 uses protein S. Both viruses depend on a viral RNA polymerase to express their proteins, but only SARS-CoV-2 has a proofreading mechanism, which results in a low mutation rate compared to influenza. E1KC4 and camostat mesylate are potential inhibitors of SARS-CoV-2 S protein, achieving an effect similar to oseltamivir. Due to the SARS-CoV-2 low mutation rate, nucleoside analogs have been developed (such as EIDD-2801), which insert lethal mutations in the viral RNA. Furthermore, the SARS-CoV-2 low mutation rate suggests that a vaccine, as well as the immunity developed in recovered patients, could provide long-lasting protection compared to vaccines against influenza, which are rendered obsolete as the virus mutates.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Influenza Humana/virologia , Pneumonia Viral/virologia , Animais , Antivirais/administração & dosagem , Antivirais/farmacologia , Betacoronavirus/imunologia , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Humanos , Vírus da Influenza A/imunologia , Vírus da Influenza A/isolamento & purificação , Influenza Humana/imunologia , Mutação , Pandemias/prevenção & controle , Pneumonia Viral/imunologia , Pneumonia Viral/prevenção & controle , Vacinas Virais
10.
Cell Host Microbe ; 28(4): 506-508, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33031768

RESUMO

The features that permit or prevent a virus from becoming a zoonotic threat is an ongoing area of investigation. In this issue of Cell Host & Microbe, Herfst et al. and Henritzi et al. help define the molecular and host determinants of influenza virus spillover from animal to human populations.


Assuntos
Vírus da Influenza A , Infecções por Orthomyxoviridae , Orthomyxoviridae , Animais , Humanos , Sus scrofa , Suínos , Zoonoses
11.
Biosens Bioelectron ; 169: 112643, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33007615

RESUMO

Detection of antibodies to upper respiratory pathogens is critical to surveillance, assessment of the immune status of individuals, vaccine development, and basic biology. The urgent need for antibody detection tools has proven particularly acute in the COVID-19 era. We report a multiplex label-free antigen microarray on the Arrayed Imaging Reflectometry (AIR) platform for detection of antibodies to SARS-CoV-2, SARS-CoV-1, MERS, three circulating coronavirus strains (HKU1, 229E, OC43) and three strains of influenza. We find that the array is readily able to distinguish uninfected from convalescent COVID-19 subjects, and provides quantitative information about total Ig, as well as IgG- and IgM-specific responses.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/sangue , Coronavirus/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Influenza Humana/sangue , Pneumonia Viral/sangue , Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Desenho de Equipamento , Células HEK293 , Humanos , Influenza Humana/diagnóstico , Influenza Humana/virologia , Coronavírus da Síndrome Respiratória do Oriente Médio/isolamento & purificação , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Análise Serial de Proteínas/instrumentação , Análise Serial de Proteínas/métodos , Vírus da SARS/isolamento & purificação , Sensibilidade e Especificidade
12.
PLoS Pathog ; 16(9): e1008842, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32898178

RESUMO

Signaling through retinoic acid inducible gene I (RIG-I) like receptors (RLRs) is tightly regulated, with activation occurring upon sensing of viral nucleic acids, and suppression mediated by negative regulators. Under homeostatic conditions aberrant activation of melanoma differentiation-associated protein-5 (MDA5) is prevented through editing of endogenous dsRNA by RNA editing enzyme Adenosine Deaminase Acting on RNA (ADAR1). In addition, ADAR1 is postulated to play pro-viral and antiviral roles during viral infections that are dependent or independent of RNA editing activity. Here, we investigated the importance of ADAR1 isoforms in modulating influenza A virus (IAV) replication and revealed the opposing roles for ADAR1 isoforms, with the nuclear p110 isoform restricting versus the cytoplasmic p150 isoform promoting IAV replication. Importantly, we demonstrate that p150 is critical for preventing sustained RIG-I signaling, as p150 deficient cells showed increased IFN-ß expression and apoptosis during IAV infection, independent of RNA editing activity. Taken together, the p150 isoform of ADAR1 is important for preventing sustained RIG-I induced IFN-ß expression and apoptosis during viral infection.


Assuntos
Adenosina Desaminase/metabolismo , Apoptose , Proteína DEAD-box 58/metabolismo , Vírus da Influenza A/fisiologia , Influenza Humana/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Replicação Viral , Células A549 , Adenosina Desaminase/genética , Proteína DEAD-box 58/genética , Células HEK293 , Humanos , Influenza Humana/genética , Isoenzimas/genética , Isoenzimas/metabolismo , Proteínas de Ligação a RNA/genética
14.
Am J Trop Med Hyg ; 103(4): 1642-1648, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32876004

RESUMO

False-negative rapid influenza diagnostic test (RIDT) results could mislead physicians to exclude an influenza diagnosis. We sought to evaluate the association between negative RIDT and intensive care unit (ICU) admission. We reviewed data from hospitalized adults with laboratory-confirmed influenza virus infections in a tertiary referral hospital in Taiwan from July 2009 to February 2011. The diagnosis was documented by real-time PCR or virus culture. Of 134 hospitalized adults infected with influenza virus, 38 (28%) were admitted to the ICU. Compared with RIDT-positive patients, the percentage of ICU admission was significantly higher among RIDT-negative patients (46% versus 13%, P < 0.001). The RIDT-negative patients had higher percentages of lower respiratory symptoms and more chest radiograph infiltrates. The time interval between the RIDT and antiviral treatment was longer in RIDT-negative than RIDT-positive patients (1.94 days versus 0.03 days, P < 0.001). Among patients presenting with mild illness, only a negative RIDT and delayed antiviral treatment were associated with ICU admission after adjusting for potential confounding factors. To conclude, patients with a negative RIDT were more likely to have severe disease and a delay in initiating antiviral treatment. Our findings should help improve treatment outcomes of hospitalized patients with influenza infection.


Assuntos
Antivirais/uso terapêutico , Vírus da Influenza A/isolamento & purificação , Influenza Humana/diagnóstico , Adulto , Idoso , Reações Falso-Negativas , Feminino , Hospitalização , Humanos , Vírus da Influenza A/genética , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Unidades de Terapia Intensiva , Laboratórios , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Taiwan
15.
PLoS Pathog ; 16(9): e1008583, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970783

RESUMO

The prospect of universal influenza vaccines is generating much interest and research at the intersection of immunology, epidemiology, and viral evolution. While the current focus is on developing a vaccine that elicits a broadly cross-reactive immune response in clinical trials, there are important downstream questions about global deployment of a universal influenza vaccine that should be explored to minimize unintended consequences and maximize benefits. Here, we review and synthesize the questions most relevant to predicting the population benefits of universal influenza vaccines and discuss how existing information could be mined to begin to address these questions. We review three research topics where computational modeling could bring valuable evidence: immune imprinting, viral evolution, and transmission. We address the positive and negative consequences of imprinting, in which early childhood exposure to influenza shapes and limits immune responses to future infections via memory of conserved influenza antigens. However, the mechanisms at play, their effectiveness, breadth of protection, and the ability to "reprogram" already imprinted individuals, remains heavily debated. We describe instances of rapid influenza evolution that illustrate the plasticity of the influenza virus in the face of drug pressure and discuss how novel vaccines could introduce new selective pressures on the evolution of the virus. We examine the possible unintended consequences of broadly protective (but infection-permissive) vaccines on the dynamics of epidemic and pandemic influenza, compared to conventional vaccines that have been shown to provide herd immunity benefits. In conclusion, computational modeling offers a valuable tool to anticipate the benefits of ambitious universal influenza vaccine programs, while balancing the risks from endemic influenza strains and unpredictable pandemic viruses. Moving forward, it will be important to mine the vast amount of data generated in clinical studies of universal influenza vaccines to ensure that the benefits and consequences of these vaccine programs have been carefully modeled and explored.


Assuntos
Anticorpos Antivirais/imunologia , Pesquisa Biomédica/tendências , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Ensaios Clínicos como Assunto , Humanos , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Influenza Humana/virologia
16.
BMC Infect Dis ; 20(1): 648, 2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32883215

RESUMO

BACKGROUND: Due to the frequent reassortment and zoonotic potential of influenza A viruses, rapid gain of sequence information is crucial. Alongside established next-generation sequencing protocols, the MinION sequencing device (Oxford Nanopore Technologies) has become a serious competitor for routine whole-genome sequencing. Here, we established a novel, rapid and high-throughput MinION multiplexing workflow based on a universal RT-PCR. METHODS: Twelve representative influenza A virus samples of multiple subtypes were universally amplified in a one-step RT-PCR and subsequently sequenced on the MinION instrument in conjunction with a barcoding library preparation kit from the rapid family and the MinIT performing live base-calling. The identical PCR products were sequenced on an IonTorrent platform and, after final consensus assembly, all data was compared for validation. To prove the practicability of the MinION-MinIT method in human and veterinary diagnostics, we sequenced recent and historical influenza strains for further benchmarking. RESULTS: The MinION-MinIT combination generated over two million reads for twelve samples in a six-hour sequencing run, from which a total of 72% classified as quality screened, trimmed and mapped influenza reads to produce full genome sequences. Identities between the datasets of > 99.9% were achieved, with 100% coverage of all segments alongside a sufficient confidence and 4492fold mean depth. From RNA extraction to finished sequences, only 14 h were required. CONCLUSIONS: Overall, we developed and validated a novel and rapid multiplex workflow for influenza A virus sequencing. This protocol suits both clinical and academic settings, aiding in real time diagnostics and passive surveillance.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Vírus da Influenza A/genética , Sequenciamento por Nanoporos/métodos , Humanos , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Fluxo de Trabalho
17.
PLoS Pathog ; 16(8): e1008775, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866218

RESUMO

Small RNA viruses only have a very limited coding capacity, thus most viral proteins have evolved to fulfill multiple functions. The highly conserved matrix protein 1 (M1) of influenza A viruses is a prime example for such a multifunctional protein, as it acts as a master regulator of virus replication whose different functions have to be tightly regulated. The underlying mechanisms, however, are still incompletely understood. Increasing evidence points towards an involvement of posttranslational modifications in the spatio-temporal regulation of M1 functions. Here, we analyzed the role of M1 tyrosine phosphorylation in genuine infection by using recombinant viruses expressing M1 phosphomutants. Presence of M1 Y132A led to significantly decreased viral replication compared to wildtype and M1 Y10F. Characterization of phosphorylation dynamics by mass spectrometry revealed the presence of Y132 phosphorylation in M1 incorporated into virions that is most likely mediated by membrane-associated Janus kinases late upon infection. Molecular dynamics simulations unraveled a potential phosphorylation-induced exposure of the positively charged linker domain between helices 4 and 5, supposably acting as interaction platform during viral assembly. Consistently, M1 Y132A showed a defect in lipid raft localization due to reduced interaction with viral HA protein resulting in a diminished structural stability of viral progeny and the formation of filamentous particles. Importantly, reduced M1-RNA binding affinity resulted in an inefficient viral genome incorporation and the production of non-infectious virions that interferes with virus pathogenicity in mice. This study advances our understanding of the importance of dynamic phosphorylation as a so far underestimated level of regulation of multifunctional viral proteins and emphasizes the potential feasibility of targeting posttranslational modifications of M1 as a novel antiviral intervention.


Assuntos
Vírus da Influenza A/metabolismo , Mutação de Sentido Incorreto , Proteínas da Matriz Viral/metabolismo , Células A549 , Substituição de Aminoácidos , Animais , Cães , Feminino , Células HEK293 , Humanos , Vírus da Influenza A/genética , Células Madin Darby de Rim Canino , Masculino , Camundongos , Camundongos Transgênicos , Fosforilação , Proteínas da Matriz Viral/genética
18.
Proc Biol Sci ; 287(1934): 20201680, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32901574

RESUMO

In this investigation, we used a combination of field- and laboratory-based approaches to assess if influenza A viruses (IAVs) shed by ducks could remain viable for extended periods in surface water within three wetland complexes of North America. In a field experiment, replicate filtered surface water samples inoculated with duck swabs were tested for IAVs upon collection and again after an overwintering period of approximately 6-7 months. Numerous IAVs were molecularly detected and isolated from these samples, including replicates maintained at wetland field sites in Alaska and Minnesota for 181-229 days. In a parallel laboratory experiment, we attempted to culture IAVs from filtered surface water samples inoculated with duck swabs from Minnesota each month during September 2018-April 2019 and found monthly declines in viral viability. In an experimental challenge study, we found that IAVs maintained in filtered surface water within wetlands of Alaska and Minnesota for 214 and 226 days, respectively, were infectious in a mallard model. Collectively, our results support surface waters of northern wetlands as a biologically important medium in which IAVs may be both transmitted and maintained, potentially serving as an environmental reservoir for infectious IAVs during the overwintering period of migratory birds.


Assuntos
Patos/virologia , Vírus da Influenza A , Influenza Aviária/virologia , Áreas Alagadas , Animais , América do Norte
19.
BMC Pulm Med ; 20(1): 239, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32907585

RESUMO

BACKGROUND: Increasing cases of pulmonary aspergillosis (IPA) in immunocompetent patients with severe influenza have been reported. Howevere, the risk factors for occurence and death are largely unknown. METHODS: Data of hospitalised patients with influenza A-related pneumonia (FluA-p) obtained from five teaching hospitals from 2031 to 2018, were reviewed. Univariate and multivariate logistical regression analyses were performed to determine the risk factors involved in the acquisition and 60-day mortality in IPA patients. RESULTS: Of the 693 FluA-p patients included in the study, 3.0% (21/693) were IPA patients with a 60-day mortality of 42.9% (9/21). Adjusted for confounders, a Cox proportional hazard model showed that IPA was associated with increased risk for 60-day mortality [hazard ratio (HR) 4.336, 95% confidence interval (CI) 1.191-15.784, p = 0.026] in FluA-p patients. A multivariate logistic regression model confirmed that age (odd ratio (OR) 1.147, 95% CI 1.048-1.225, p = 0.003), systemic corticosteroids use before IPA diagnosis (OR 33.773, 95% CI 5.681-76.764, p <  0.001), leukocytes > 10 × 109/L (OR 1.988, 95% CI 1.028-6.454, p = 0.029) and lymphocytes < 0.8 × 109/L on admission (OR 34.813, 95% CI 1.676-73.006, p = 0.022), were related with the acquisition of IPA. Early neuraminidase inhibitor use (OR 0.290, 95% CI 0.002-0.584, p = 0.021) was associated with a decreased risk for a 60-day mortality in IPA patients. CONCLUSIONS: Our results showed that IPA worsen the clinical outcomes of FluA-p patients. The risk factors for the acquisition and death were helpful for the clinicians in preventing and treating IPA.


Assuntos
Hospitalização , Vírus da Influenza A , Influenza Humana/complicações , Aspergilose Pulmonar Invasiva/complicações , Pneumonia Viral/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imunocompetência , Influenza Humana/mortalidade , Aspergilose Pulmonar Invasiva/mortalidade , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/mortalidade , Estudos Retrospectivos , Fatores de Risco
20.
BMC Med Inform Decis Mak ; 20(1): 247, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993652

RESUMO

BACKGROUND: The recent Coronavirus Disease 2019 (COVID-19) pandemic has placed severe stress on healthcare systems worldwide, which is amplified by the critical shortage of COVID-19 tests. METHODS: In this study, we propose to generate a more accurate diagnosis model of COVID-19 based on patient symptoms and routine test results by applying machine learning to reanalyzing COVID-19 data from 151 published studies. We aim to investigate correlations between clinical variables, cluster COVID-19 patients into subtypes, and generate a computational classification model for discriminating between COVID-19 patients and influenza patients based on clinical variables alone. RESULTS: We discovered several novel associations between clinical variables, including correlations between being male and having higher levels of serum lymphocytes and neutrophils. We found that COVID-19 patients could be clustered into subtypes based on serum levels of immune cells, gender, and reported symptoms. Finally, we trained an XGBoost model to achieve a sensitivity of 92.5% and a specificity of 97.9% in discriminating COVID-19 patients from influenza patients. CONCLUSIONS: We demonstrated that computational methods trained on large clinical datasets could yield ever more accurate COVID-19 diagnostic models to mitigate the impact of lack of testing. We also presented previously unknown COVID-19 clinical variable correlations and clinical subgroups.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Influenza Humana/diagnóstico , Aprendizado de Máquina , Pneumonia Viral/diagnóstico , Betacoronavirus , Simulação por Computador , Infecções por Coronavirus/classificação , Conjuntos de Dados como Assunto , Diagnóstico Diferencial , Feminino , Humanos , Vírus da Influenza A , Masculino , Pandemias/classificação , Pneumonia Viral/classificação , Sensibilidade e Especificidade
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