Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 851
Filtrar
1.
Nat Commun ; 11(1): 164, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919360

RESUMO

Host dependency factors that are required for influenza A virus infection may serve as therapeutic targets as the virus is less likely to bypass them under drug-mediated selection pressure. Previous attempts to identify host factors have produced largely divergent results, with few overlapping hits across different studies. Here, we perform a genome-wide CRISPR/Cas9 screen and devise a new approach, meta-analysis by information content (MAIC) to systematically combine our results with prior evidence for influenza host factors. MAIC out-performs other meta-analysis methods when using our CRISPR screen as validation data. We validate the host factors, WDR7, CCDC115 and TMEM199, demonstrating that these genes are essential for viral entry and regulation of V-type ATPase assembly. We also find that CMTR1, a human mRNA cap methyltransferase, is required for efficient viral cap snatching and regulation of a cell autonomous immune response, and provides synergistic protection with the influenza endonuclease inhibitor Xofluza.


Assuntos
Predisposição Genética para Doença/genética , Interações Hospedeiro-Patógeno/genética , Vírus da Influenza A/patogenicidade , Influenza Humana/genética , Influenza Humana/patologia , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/genética , Antivirais/farmacologia , Sistemas CRISPR-Cas , Linhagem Celular , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Estudo de Associação Genômica Ampla , Humanos , Proteínas de Membrana/genética , Metiltransferases/metabolismo , Proteínas do Tecido Nervoso/genética , Oxazinas/farmacologia , Piridinas/farmacologia , Tiepinas/farmacologia , Triazinas/farmacologia , ATPases Vacuolares Próton-Translocadoras/metabolismo , Internalização do Vírus
2.
PLoS Pathog ; 15(10): e1008034, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31581279

RESUMO

The influenza A virus RNA-dependent RNA polymerase complex consists in three subunits, PB2, PB1 and PA, that perform transcription and replication of the viral genome through very distinct mechanisms. Biochemical and structural studies have revealed that the polymerase can adopt multiple conformations and form oligomers. However so far it remained unclear whether the available oligomeric crystal structures represent a functional state of the polymerase. Here we gained new insights into this question, by investigating the incompatibility between non-cognate subunits of influenza polymerase brought together through genetic reassortment. We observed that a 7:1 reassortant virus whose PB2 segment derives from the A/WSN/33 (WSN) virus in an otherwise A/PR/8/34 (PR8) backbone is attenuated, despite a 97% identity between the PR8-PB2 and WSN-PB2 proteins. Independent serial passages led to the selection of phenotypic revertants bearing distinct second-site mutations on PA, PB1 and/or PB2. The constellation of mutations present on one revertant virus was studied extensively using reverse genetics and cell-based reconstitution of the viral polymerase. The PA-E349K mutation appeared to play a major role in correcting the initial defect in replication (cRNA -> vRNA) of the PR8xWSN-PB2 reassortant. Strikingly the PA-E349K mutation, and also the PB2-G74R and PB1-K577G mutations present on other revertants, are located at a dimerization interface of the polymerase. All three restore wild-type-like polymerase activity in a minigenome assay while decreasing the level of polymerase dimerization. Overall, our data show that the polymerase subunits co-evolve to ensure not only optimal inter-subunit interactions within the heterotrimer, but also proper levels of dimerization of the heterotrimer which appears to be essential for efficient viral RNA replication. Our findings point to influenza polymerase dimerization as a feature that is controlled by a complex interplay of genetic determinants, can restrict genetic reassortment, and could become a target for antiviral drug development.


Assuntos
Vírus da Influenza A/enzimologia , Influenza Humana/virologia , Mutação , Multimerização Proteica , RNA Replicase/química , RNA Replicase/genética , Vírus Reordenados/genética , Células A549 , Células HEK293 , Humanos , Influenza Humana/genética , Conformação Proteica , Subunidades Proteicas , RNA Replicase/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo , Replicação Viral
3.
Int J Mol Sci ; 20(20)2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623059

RESUMO

Long noncoding RNAs (lncRNAs) are involved in a diversity of biological processes. It is known that differential expression of thousands of lncRNAs occurs in host during influenza A virus (IAV) infection. However, only few of them have been well characterized. Here, we identified a lncRNA, named as interferon (IFN)-stimulated lncRNA (ISR), which can be significantly upregulated in response to IAV infection in a mouse model. A sequence alignment revealed that lncRNA ISR is present in mice and human beings, and indeed, we found that it was expressed in several human and mouse cell lines and tissues. Silencing lncRNA ISR in A549 cells resulted in a significant increase in IAV replication, whereas ectopic expression of lncRNA ISR reduced the viral replication. Interestingly, interferon-ß (IFN-ß) treatment was able to induce lncRNA ISR expression, and induction of lncRNA ISR by viral infection was nearly abolished in host deficient of IFNAR1, a type I IFN receptor. Furthermore, the level of IAV-induced lncRNA ISR expression was decreased either in retinoic acid-inducible gene I (RIG-I) knockout A549 cells and mice or by nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) inhibitor treatment. Together, these data elucidate that lncRNA ISR is regulated by RIG-I-dependent signaling that governs IFN-ß production during IAV infection, and has an inhibitory capacity in viral replication.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Vírus da Influenza A/fisiologia , Influenza Humana/genética , Influenza Humana/virologia , Interferons/farmacologia , RNA Longo não Codificante/genética , Replicação Viral , Animais , Linhagem Celular , Feminino , Humanos , Camundongos , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/virologia
4.
Emerg Microbes Infect ; 8(1): 1465-1478, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31608791

RESUMO

The ANP32A is responsible for mammalian-restricted influenza virus polymerase activity. However, the mechanism of ANP32A modulation of polymerase activity remains poorly understood. Here, we report that chicken ANP32A (chANP32A) -X1 and -X2 stimulated mammalian-restricted PB2 627E polymerase activity in a dose-dependent manner. Distinct effects of ANP32A constructs suggested that the 180VK181 residues within chANP32A-X1 are necessary but not sufficient to stimulate PB2 627E polymerase activity. The PB2 N567D, T598V, A613V or F636L mutations promoted PB2 627E polymerase activity and chANP32A-X1 showed additive effects, providing further support that species-specific regulation of ANP32A might be only relevant with the PB2 E627K mutation. Rescue of cycloheximide-mediated inhibition showed that ANP32A is species-specific for modulation of vRNA but not mRNA and cRNA, demonstrating chANP32A-X1 compensated for defective cRNPs produced by PB2 627E virus in mammalian cells. The promoter mutations of cRNA enhanced the restriction of PB2 627E polymerase in mammalian cells, which could be restored by chANP32A-X1, indicating that ANP32A is likely to regulate the interaction of viral polymerase with RNA promoter. Coimmunoprecipitation showed that ANP32A did not affect the primary cRNPs assembly. We propose a model that chANP32A-X1 regulates PB2 627E polymerase for suitable interaction with cRNA promoter for vRNA replication.


Assuntos
Vírus da Influenza A Subtipo H1N1/enzimologia , Subtipo H7N9 do Vírus da Influenza A/enzimologia , Vírus da Influenza A Subtipo H9N2/enzimologia , Influenza Aviária/metabolismo , Influenza Humana/metabolismo , Doenças das Aves Domésticas/metabolismo , RNA Replicase/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Animais , Galinhas , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/fisiologia , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/fisiologia , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/fisiologia , Influenza Aviária/genética , Influenza Aviária/virologia , Influenza Humana/genética , Influenza Humana/virologia , Mutação , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/virologia , Ligação Proteica , RNA Replicase/genética , RNA Viral/genética , RNA Viral/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Alinhamento de Sequência , Especificidade da Espécie , Proteínas Virais/genética , Replicação Viral
5.
Indian J Med Res ; 149(6): 783-789, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31496532

RESUMO

Background & objectives: Influenza virological surveillance is an essential tool for the early detection of novel genetic variants of epidemiologic and clinical significance. This study was aimed to genetically characterize A(H1N1)pdm09 virus circulating in 2017 and to compare it with the global data. Methods: The regional/State Viral Research and Diagnostic Laboratories (VRDLs) provided influenza diagnosis for referred clinical samples and shared influenza A(H1N1)pdm09 positives with the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV), Pune, India, for hemagglutinin (HA) gene phylogenetic analysis. Sites at Manipal, Jaipur and Dibrugarh performed the sequencing and shared the sequence data for analysis. The antiviral susceptibility of influenza viruses was assessed for known molecular marker H275Y at the ICMR-NIV, Pune. Results: All the eight VRDLs had well-established influenza diagnostic facilities and showed increased activity of influenza A(H1N1)pdm09 during 2017. Phylogenetic analysis showed that the viruses from the different regions of the country were similar to A/Michigan/45/2015 strain which was the 2017-2018 recommended vaccine strain and were clustered with the globally circulating clade 6B.1 with signature mutations S84N, S162N and I216T. The clade 6B.1 showed further subgrouping with additional mutations S74R, S164T and I295V; however, there was no significant association between the presence of these mutations and severity of disease due to influenza. All the study viruses were sensitive to oseltamivir. Interpretation & conclusions: During the study period, all the study sites reported globally circulating A/Michigan/45/2015 vaccine strain of influenza A(H1N1)pdm09 viruses and remained sensitive to oseltamivir. Further genetic and antigenic characterization of influenza viruses is recommended to address public health concerns.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/genética , Oseltamivir/uso terapêutico , Filogenia , Antivirais/uso terapêutico , Farmacorresistência Viral/genética , Humanos , Índia/epidemiologia , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vacinas contra Influenza/uso terapêutico , Influenza Humana/tratamento farmacológico , Influenza Humana/patologia , Influenza Humana/virologia , Mutação de Sentido Incorreto/genética , RNA Viral/genética , Análise de Sequência de DNA
6.
Nat Commun ; 10(1): 3396, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363119

RESUMO

Species' differences in cellular factors limit avian influenza A virus (IAV) zoonoses and human pandemics. The IAV polymerase, vPol, harbors evolutionary sites to overcome restriction and determines virulence. Here, we establish host ANP32A as a critical driver of selection, and identify host-specific ANP32A splicing landscapes that predict viral evolution. We find that avian species differentially express three ANP32A isoforms diverging in a vPol-promoting insert. ANP32As with shorter inserts interact poorly with vPol, are compromised in supporting avian-like IAV replication, and drive selection of mammalian-adaptive vPol sequences with distinct kinetics. By integrating selection data with multi-species ANP32A splice variant profiling, we develop a mathematical model to predict avian species potentially driving (swallow, magpie) or maintaining (goose, swan) mammalian-adaptive vPol signatures. Supporting these predictions, surveillance data confirm enrichment of several mammalian-adaptive vPol substitutions in magpie IAVs. Profiling host ANP32A splicing could enhance surveillance and eradication efforts against IAVs with pandemic potential.


Assuntos
Vírus da Influenza A/enzimologia , Influenza Aviária/genética , Processamento de RNA , Proteínas de Ligação a RNA/genética , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Animais , Aves , Galinhas , Humanos , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A/química , Vírus da Influenza A/genética , Vírus da Influenza A/fisiologia , Influenza Aviária/metabolismo , Influenza Aviária/virologia , Influenza Humana/genética , Influenza Humana/metabolismo , Influenza Humana/virologia , Ligação Proteica , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Replicação Viral
7.
Virus Genes ; 55(6): 739-768, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31428925

RESUMO

Avian influenza viruses (AIVs) circulate globally, spilling over into domestic poultry and causing zoonotic infections in humans. Fortunately, AIVs are not yet capable of causing sustained human-to-human infection; however, AIVs are still a high risk as future pandemic strains, especially if they acquire further mutations that facilitate human infection and/or increase pathogenesis. Molecular characterization of sequencing data for known genetic markers associated with AIV adaptation, transmission, and antiviral resistance allows for fast, efficient assessment of AIV risk. Here we summarize and update the current knowledge on experimentally verified molecular markers involved in AIV pathogenicity, receptor binding, replicative capacity, and transmission in both poultry and mammals with a broad focus to include data available on other AIV subtypes outside of A/H5N1 and A/H7N9.


Assuntos
Marcadores Genéticos/genética , Influenza Aviária/genética , Influenza Humana/genética , Zoonoses/genética , Animais , Aves/genética , Aves/virologia , Farmacorresistência Viral/genética , Humanos , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/patogenicidade , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Influenza Humana/virologia , Pandemias , Aves Domésticas/genética , Aves Domésticas/virologia , Zoonoses/virologia
8.
PLoS Pathog ; 15(8): e1007892, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31415678

RESUMO

The M segment of the 2009 pandemic influenza A virus (IAV) has been implicated in its emergence into human populations. To elucidate the genetic contributions of the M segment to host adaptation, and the underlying mechanisms, we examined a panel of isogenic viruses that carry avian- or human-derived M segments. Avian, but not human, M segments restricted viral growth and transmission in mammalian model systems, and the restricted growth correlated with increased expression of M2 relative to M1. M2 overexpression was associated with intracellular accumulation of autophagosomes, which was alleviated by interference of the viral proton channel activity by amantadine treatment. As M1 and M2 are expressed from the M mRNA through alternative splicing, we separated synonymous and non-synonymous changes that differentiate human and avian M segments and found that dysregulation of gene expression leading to M2 overexpression diminished replication, irrespective of amino acid composition of M1 or M2. Moreover, in spite of efficient replication, virus possessing a human M segment that expressed avian M2 protein at low level did not transmit efficiently. We conclude that (i) determinants of transmission reside in the IAV M2 protein, and that (ii) control of M segment gene expression is a critical aspect of IAV host adaptation needed to prevent M2-mediated dysregulation of vesicular homeostasis.


Assuntos
Aves/virologia , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Humana/virologia , Infecções por Orthomyxoviridae/virologia , Proteínas da Matriz Viral/metabolismo , Replicação Viral , Células A549 , Animais , Cães , Feminino , Cobaias , Humanos , Influenza Humana/genética , Influenza Humana/metabolismo , Células Madin Darby de Rim Canino , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/metabolismo , Especificidade da Espécie , Proteínas da Matriz Viral/genética
9.
Nat Microbiol ; 4(11): 1964-1977, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31358986

RESUMO

Despite the cytopathic nature of influenza A virus (IAV) replication, we recently reported that a subset of lung epithelial club cells is able to intrinsically clear the virus and survive infection. However, the mechanisms that drive cell survival during a normally lytic infection remained unclear. Using a loss-of-function screening approach, we discovered that the DNA mismatch repair (MMR) pathway is essential for club cell survival of IAV infection. Repair of virally induced oxidative damage by the DNA MMR pathway not only allowed cell survival of infection, but also facilitated host gene transcription, including the expression of antiviral and stress response genes. Enhanced viral suppression of the DNA MMR pathway prevented club cell survival and increased the severity of viral disease in vivo. Altogether, these results identify previously unappreciated roles for DNA MMR as a central modulator of cellular fate and a contributor to the innate antiviral response, which together control influenza viral disease severity.


Assuntos
Reparo de Erro de Pareamento de DNA , Redes Reguladoras de Genes , Imunidade Inata , Vírus da Influenza A/patogenicidade , Influenza Humana/genética , Células A549 , Animais , Linhagem Celular , Modelos Animais de Doenças , Cães , Regulação da Expressão Gênica , Humanos , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Células Madin Darby de Rim Canino , Camundongos , Estresse Oxidativo , Replicação Viral
10.
Virology ; 534: 80-86, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31220651

RESUMO

The immunopathological mechanisms as well as the role played by influenza A virus infection of human leukocytes and induction of apoptosis have not been fully elucidated. We confirm here that the percentage of cells that are infected is less than the percent of apoptotic cells. Depletion of monocytes/macrophages and depletion of cells expressing influenza neuraminidase from the cultures after exposure to virus decreased lymphocyte apoptosis. Treatment of virus-exposed leukocyte cultures with anti-neuraminidase antibodies but not with anti-hemagglutinin antibodies, reduced lymphocyte production of active caspase-3 and induction of apoptosis. Different strains of virus induced different levels of apoptosis. Variations in induction of apoptosis correlated with production and expression of viral neuraminidase by infected leukocytes. The data suggest that cell surface expression of neuraminidase plays an important role in the induction of apoptosis in human lymphocytes. The benefit, or cost, to the host of lymphocyte apoptosis warrants continued investigation.


Assuntos
Apoptose , Membrana Celular/virologia , Vírus da Influenza A/enzimologia , Influenza Humana/virologia , Linfócitos/citologia , Neuraminidase/metabolismo , Proteínas Virais/metabolismo , Animais , Caspase 3/genética , Caspase 3/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A/genética , Influenza Humana/enzimologia , Influenza Humana/genética , Influenza Humana/fisiopatologia , Linfócitos/virologia , Neuraminidase/genética , Proteínas Virais/genética
11.
Virology ; 534: 54-63, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31176924

RESUMO

Influenza A virus (IAV) infections result in ∼500,000 global deaths annually. Host kinases link multiple signaling pathways at various stages of infection and are attractive therapeutic target. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, regulates several cellular processes including NFkB and antiviral responses. We investigated how FAK kinase activity regulates IAV pathogenesis. Using a severe infection model, we infected IAV-susceptible DBA/2 J mice with a lethal dose of H1N1 IAV. We observed reduced viral load and pro-inflammatory cytokines, delayed mortality, and increased survival in FAK inhibitor (Y15) treated mice. In vitro IAV-induced NFkB-promoter activity was reduced by Y15 or a dominant negative kinase-dead FAK mutant (FAK-KD) independently of the viral immune modulator, NS1. Finally, we observed reduced IAV-induced nuclear localization of NFkB in FAK-KD expressing cells. Our data suggest a novel mechanism where IAV hijacks FAK to promote viral replication and limit its ability to contribute to innate immune responses.


Assuntos
Proteína-Tirosina Quinases de Adesão Focal/imunologia , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/enzimologia , NF-kappa B/imunologia , Provírus/patogenicidade , Animais , Feminino , Proteína-Tirosina Quinases de Adesão Focal/genética , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/genética , Influenza Humana/imunologia , Influenza Humana/virologia , Camundongos , Camundongos Endogâmicos DBA , NF-kappa B/genética , Regiões Promotoras Genéticas , Provírus/genética , Provírus/fisiologia , Carga Viral , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Virulência , Replicação Viral
12.
PLoS One ; 14(5): e0217691, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31150476

RESUMO

By comparing and measuring covariations of viral protein sequences from isolates of the 2009 pH1N1 influenza A virus (IAV), specific substitutions that co-occur in the NP-NA pair were identified. To investigate the effect of these co-occurring substitution pairs, the V100I substitution in NP and the D248N substitution in NA were introduced into laboratory-adapted WSN IAVs. The recombinant WSN with the covarying NPV100I-NAD248N pair exhibited enhanced pathogenicity, as characterized by increased viral production, increased death and inflammation of host cells, and high mortality in infected mice. Although direct interactions between the NPV100I and NAD248N proteins were not detected, the RNA-binding ability of NPV100I was increased, which was further strengthened by NAD248N, in expression-plasmid-transfected cells. Additionally, the NAD248N protein was frequently recruited within lipid rafts, indirectly affecting the RNA-binding ability of NP as well as viral release. Altogether, our data indicate that the covarying NPV100I-NAD248N pair obtained from 2009 pH1N1 IAV sequence information function together to synergistically augment viral assembly and release, which may explain the observed enhanced viral pathogenicity.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/genética , Proteínas do Core Viral/genética , Proteínas Virais/genética , Animais , Células HEK293 , Interações Hospedeiro-Patógeno/genética , Humanos , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/virologia , Camundongos , Replicação Viral/genética
13.
Sci Total Environ ; 682: 208-212, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31121347

RESUMO

Few studies have examined the relationship between exposure to germanium (Ge) and the risk of influenza-like illness (ILI). Therefore, we investigated the association of Ge exposure and its interaction with single nucleotide polymorphisms (SNPs) related to Phase II metabolism on ILI risk among housewives in Shanxi Province, northern China. This cross-sectional study enrolled 373 housewives. Information on the housewives' characteristics and the frequency of ILI was collected by questionnaire. We analyzed the Ge concentrations in hair samples taken from near the scalp at the back of the head. Blood samples were used to identify SNPs related to Phase II metabolism. The results suggested that the hair Ge concentration was associated with ILI risk with an adjusted odds ratio and 95% confidence interval of 2.59 (1.61-4.19). A significant dose-response relationship was observed without or with adjusting for confounders. We did not observe any interaction effect between the hair Ge concentration and the SNPs on ILI risk. We found that high dietary consumption of meat and fried foods was positively correlated with the hair Ge concentration. Therefore, chronic Ge exposure may be a risk factor for an increased frequency of ILI in housewives.


Assuntos
Exposição Ambiental , Germânio/efeitos adversos , Influenza Humana/epidemiologia , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , China/epidemiologia , Estudos Transversais , Relação Dose-Resposta a Droga , Feminino , Cabelo/química , Humanos , Influenza Humana/induzido quimicamente , Influenza Humana/genética , Desintoxicação Metabólica Fase II , Pessoa de Meia-Idade , Fatores de Risco
14.
PLoS One ; 14(5): e0216308, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31063477

RESUMO

STUDY OBJECTIVE: To investigate the performance of a rapid RT-PCR assay to detect influenza A/B at emergency department admission. METHODS: This single-center prospective study recruited adult patients attending the emergency department for influenza-like illness. Triage nurses performed nasopharyngeal swab samples and ran rapid RT-PCR assays using a dedicated device (cobas Liat, Roche Diagnostics, Meylan, France) located at triage. The same swab sample was also analyzed in the department of virology using conventional RT-PCR techniques. Patients were included 24 hours-a-day, 7 days-a-week. The primary outcome was the diagnostic accuracy of the rapid RT-PCR assay performed at triage. RESULTS: A total of 187 patients were included over 11 days in January 2018. Median age was 70 years (interquartile range 44 to 84) and 95 (51%) were male. Nine (5%) assays had to be repeated due to failure of the first assay. The sensitivity of the rapid RT-PCR assay performed at triage was 0.98 (95% confidence interval (CI): 0.91-1.00) and the specificity was 0.99 (95% CI: 0.94-1.00). A total of 92 (49%) assays were performed at night-time or during the weekend. The median time from patient entry to rapid RT-PCR assay results was 46 [interquartile range 36-55] minutes. CONCLUSION: Rapid RT-PCR assay performed by nurses at triage to detect influenza A/B is feasible and highly accurate.


Assuntos
Vírus da Influenza A/genética , Vírus da Influenza B/genética , Influenza Humana , Técnicas de Diagnóstico Molecular , Sistemas Automatizados de Assistência Junto ao Leito , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto , Idoso , Idoso de 80 Anos ou mais , Serviço Hospitalar de Emergência , Feminino , França/epidemiologia , Humanos , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Influenza Humana/genética , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estações do Ano , Manejo de Espécimes
15.
Emerg Microbes Infect ; 8(1): 556-563, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30945621

RESUMO

The human innate immune factor MxA represents an effective interspecies barrier for zoonotic influenza A viruses (IAVs) of animal origin. Accordingly, human but not avian IAVs efficiently escape the antiviral activity of MxA due to adaptive mutations in their viral nucleoprotein. Partial MxA resistance can be acquired in intermediate hosts such as swine, which possess an antivirally active Mx1 protein. Intriguingly, Mx1 of the bat Carollia perspicillata, a host of the recently discovered bat influenza A-like virus H18N11, is antivirally active against avian IAVs, thus raising the question whether H18N11 has undergone a preadaptation to human MxA. Here, by utilizing a chimeric bat influenza virus, PR8-H18N11, we demonstrate that MxA efficiently blocks viral replication in vitro as well as in MxA transgenic mice. Nevertheless, the H18N11 nucleoprotein exhibits partial MxA resistance in a polymerase reconstitution assay, suggesting that a certain degree of MxA preadaptation occurred. Together, our data indicate a currently reduced risk for H18N11 to overcome the human restriction factor MxA. Further adaptive mutations in NP are required to facilitate full MxA escape.


Assuntos
Quirópteros/virologia , Vírus da Influenza A/fisiologia , Influenza Humana/imunologia , Proteínas de Resistência a Myxovirus/imunologia , Infecções por Orthomyxoviridae/veterinária , Animais , Linhagem Celular , Humanos , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Influenza Humana/genética , Influenza Humana/virologia , Camundongos Endogâmicos C57BL , Proteínas de Resistência a Myxovirus/genética , Nucleoproteínas/genética , Nucleoproteínas/metabolismo , Infecções por Orthomyxoviridae/virologia , Replicação Viral
16.
PLoS Comput Biol ; 15(4): e1006899, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30939133

RESUMO

Small sample sizes combined with high person-to-person variability can make it difficult to detect significant gene expression changes from transcriptional profiling studies. Subtle, but coordinated, gene expression changes may be detected using gene set analysis approaches. Meta-analysis is another approach to increase the power to detect biologically relevant changes by integrating information from multiple studies. Here, we present a framework that combines both approaches and allows for meta-analysis of gene sets. QuSAGE meta-analysis extends our previously published QuSAGE framework, which offers several advantages for gene set analysis, including fully accounting for gene-gene correlations and quantifying gene set activity as a full probability density function. Application of QuSAGE meta-analysis to influenza vaccination response shows it can detect significant activity that is not apparent in individual studies.


Assuntos
Perfilação da Expressão Gênica/estatística & dados numéricos , Expressão Gênica , Software , Biologia Computacional , Humanos , Influenza Humana/genética , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Probabilidade , Vacinação
17.
Biomed J ; 42(1): 19-26, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30987701

RESUMO

The role of host genetics in influenza infection is unclear despite decades of interest. Confounding factors such as age, sex, ethnicity and environmental factors have made it difficult to assess the role of genetics without influence. In recent years a single nucleotide polymorphism, interferon-induced transmembrane protein 3 (IFITM3) rs12252, has been shown to alter the severity of influenza infection in Asian populations. In this review we investigate this polymorphism as well as several others suggested to alter the host's defence against influenza infection. In addition, we highlight the open questions surrounding the viral restriction protein IFITM3 with the hope that by answering some of these questions we can elucidate the mechanism of IFITM3 viral restriction and therefore how this restriction is altered due to the rs12252 polymorphism.


Assuntos
Predisposição Genética para Doença/genética , Influenza Humana/genética , Interferons/genética , Proteínas de Membrana/genética , Proteínas de Ligação a RNA/genética , Genótipo , Humanos , Influenza Humana/imunologia , Interferons/imunologia , Proteínas de Membrana/imunologia , Proteínas de Ligação a RNA/imunologia
18.
Front Immunol ; 10: 180, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30873150

RESUMO

Background: Sex differences in immune responses to influenza vaccine may impact efficacy across populations. Methods: In a cohort of 138 older adults (50-74 years old), we measured influenza A/H1N1 antibody titers, B-cell ELISPOT response, PBMC transcriptomics, and PBMC cell compositions at 0, 3, and 28 days post-immunization with the 2010/11 seasonal inactivated influenza vaccine. Results: We identified higher B-cell ELISPOT responses in females than males. Potential mechanisms for sex effects were identified in four gene clusters related to T, NK, and B cells. Mediation analysis indicated that sex-dependent expression in T and NK cell genes can be partially attributed to higher CD4+ T cell and lower NK cell fractions in females. We identified strong sex effects in 135 B cell genes whose expression correlates with ELISPOT measures, and found that cell subset differences did not explain the effect of sex on these genes' expression. Post-vaccination expression of these genes, however, mediated 41% of the sex effect on ELISPOT responses. Conclusions: These results improve our understanding of sexual dimorphism in immunity and influenza vaccine response.


Assuntos
Imunidade , Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Fatores Etários , Idoso , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Biomarcadores , ELISPOT , Feminino , Avaliação Geriátrica , Humanos , Imunidade Celular , Imunidade Humoral , Influenza Humana/genética , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Linfócitos T/imunologia , Linfócitos T/metabolismo , Vacinação
19.
PLoS One ; 14(3): e0212757, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30822349

RESUMO

Influenza A virus (IAV) infection poses a serious health threat and novel antiviral strategies are needed. Defective interfering particles (DIPs) can be generated in IAV infected cells due to errors of the viral polymerase and may suppress spread of wild type (wt) virus. The antiviral activity of DIPs is exerted by a DI genomic RNA segment that usually contains a large deletion and suppresses amplification of wt segments, potentially by competing for cellular and viral resources. DI-244 is a naturally occurring prototypic segment 1-derived DI RNA in which most of the PB2 open reading frame has been deleted and which is currently developed for antiviral therapy. At present, coinfection with wt virus is required for production of DI-244 particles which raises concerns regarding biosafety and may complicate interpretation of research results. Here, we show that cocultures of 293T and MDCK cell lines stably expressing codon optimized PB2 allow production of DI-244 particles solely from plasmids and in the absence of helper virus. Moreover, we demonstrate that infectivity of these particles can be quantified using MDCK-PB2 cells. Finally, we report that the DI-244 particles produced in this novel system exert potent antiviral activity against H1N1 and H3N2 IAV but not against the unrelated vesicular stomatitis virus. This is the first report of DIP production in the absence of infectious IAV and may spur efforts to develop DIPs for antiviral therapy.


Assuntos
Vírus Defeituosos , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A Subtipo H3N2 , Influenza Humana , Animais , Vírus Defeituosos/genética , Vírus Defeituosos/imunologia , Cães , Células HEK293 , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Influenza Humana/genética , Influenza Humana/imunologia , Células Madin Darby de Rim Canino , Células Vero
20.
Nano Lett ; 19(3): 1875-1882, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30719917

RESUMO

Viruses, such as influenza A, typically bind to the plasma membrane of their host by engaging multiple membrane receptors in parallel, thereby forming so-called multivalent interactions that are created by the collective action of multiple weak ligand-receptor bonds. The overall interaction strength can be modulated by changing the number of engaged receptors. This feature is used by viruses to achieve a sufficiently firm attachment to the host's plasma membrane but also allows progeny viruses to leave the plasma membrane after completing the virus replication cycle. Design of strategies to prevent infection, for example, by disturbing these attachment and detachment processes upon application of antivirals, requires quantification of the underlying multivalent interaction in absence and presence of antivirals. This is still an unresolved problem, as there is currently no approach available that allows for determining the valency (i.e., of the number of receptors bound to a particular virus) on the level of single viruses under equilibrium conditions. Herein, we track the motion of single influenza A/X31 viruses (IAVs; interacting with the ganglioside GD1a incorporated in a supported lipid bilayer) using total internal reflection fluorescence microscopy and show that IAV residence time distributions can be deconvoluted from valency effects by taking the IAV mobility into account. The so-derived off-rate distributions, expressed in dependence of an average, apparent valency, show the expected decrease in off-rate with increasing valency but also show an unexpected peak structure, which can be linked to a competition in the opposing functionalities of the two influenza A virus spike proteins, hemagglutinin (HA), and neuraminidase (NA). By application of the antiviral zanamivir that inhibits the activity of NA, we provide direct evidence, how the HA/NA balance modulates this virus-receptor interaction, allowing us to assess the inhibition concentration of zanamivir based on its effect on the multivalent interaction.


Assuntos
Hemaglutininas/química , Influenza Humana/virologia , Neuraminidase/química , Receptores Virais/química , Membrana Celular/química , Gangliosídeo G(M1)/análogos & derivados , Gangliosídeo G(M1)/química , Hemaglutininas/genética , Humanos , Vírus da Influenza A/química , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Humana/genética , Bicamadas Lipídicas/química , Neuraminidase/antagonistas & inibidores , Neuraminidase/genética , Receptores Virais/genética , Zanamivir
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA