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2.
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
3.
Am J Pathol ; 190(3): 543-553, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31866346

RESUMO

Chronic obstructive pulmonary disease (COPD) and asthma remain prevalent human lung diseases. Variability in epithelial and inflammatory components that results in pathologic heterogeneity complicates the development of treatments for these diseases. Early childhood infection with parainfluenza virus or respiratory syncytial virus is strongly associated with the development of asthma and COPD later in life, and exacerbations of these diseases correlate with the presence of viral RNA in the lung. Well-characterized animal models of postviral chronic lung diseases are necessary to study the underlying mechanisms of viral-related COPD and asthma and to develop appropriate therapies. In this study, we cross-analyzed chronic lung disease caused by infection with Sendai virus (SeV) or influenza A virus in mice. Differences were observed in lesion composition and inflammatory profiles between SeV- and influenza A virus-induced long-term lung disease. In addition, a primary SeV infection led to worsened pathologic findings on secondary heterologous viral challenge, whereas the reversed infection scheme protected against disease in response to a secondary viral challenge >1 month after the primary infection. These data demonstrate the differential effect of primary viral infections in the susceptibility to disease exacerbation in response to a different secondary viral infection and highlight the usefulness of these viral models as tools to understand the underlying mechanisms that mediate distinct chronic postviral lung diseases.


Assuntos
Asma/patologia , Vírus da Influenza A/fisiologia , Influenza Humana/patologia , Infecções por Paramyxoviridae/patologia , Paramyxoviridae/fisiologia , Doença Pulmonar Obstrutiva Crônica/virologia , Superinfecção/patologia , Animais , Asma/virologia , Doença Crônica , Progressão da Doença , Feminino , Humanos , Influenza Humana/virologia , Pulmão/patologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Paramyxoviridae/virologia , Superinfecção/virologia
4.
BMC Infect Dis ; 19(1): 1012, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31783806

RESUMO

BACKGROUND: Influenza is the most frequent cause of acute upper respiratory tract infections during winter season. Although rare, neurological manifestations are known to occur during influenza infection and approximatively three-quarters of cases are in children. In this study, we aimed to characterize the burden and clinical spectrum of influenza-associated encephalopathy and encephalitis in children admitted at a tertiary pediatric hospital in Italy over two influenza seasons (2017-2019). METHODS: We retrospectively analyzed clinical, laboratory, instrumental data and outcome of patients discharged with ICD9-CM 487.0 code. RESULTS: Fifteen children (13.1% of those discharged with a diagnosis of influenza infection in the study period), had influenza-associated central nervous system (CNS) manifestations. Eight patients (53.3%) were diagnosed as influenza encephalitis, 7 (46.7%) as influenza encephalopathy. Median age was 27 months. In children under 2 years of age (40% of all cases) altered consciousness was the most frequent neurological manifestation while respiratory symptoms were present at admission in all cases. Younger children also required intensive care support more frequently. Five subjects (33.3%) presented comorbidity. None of the patients had received seasonal influenza vaccination. The median time from onset of respiratory signs to onset of neurological manifestations was 24 h. Cerebrospinal fluid (CSF) analysis was normal in most patients and polymerase chain reaction for influenza virus RNA on CSF, when performed, was negative in all samples. Neuroradiological investigations, performed in 5 children, reported cortical and subcortical white matter signal alterations. Oseltamivir was administered only in 2 cases. Fourteen patients recovered without sequelae, and only a 2-year-old girl had minimal impairment in fine motor skills at discharge. CONCLUSIONS: All children presenting acute neurological features during influenza season should be evaluated for influenza-associated CNS complications even if the respiratory involvement is mild. Absence of underlying diseases or other risk factors are not protective factors against CNS influenza-associated complications. The lack of CSF pleocytosis does not exclude CNS involvement. Children under 2 years of age are at higher risk of requiring intensive care support.


Assuntos
Encefalite/diagnóstico , Influenza Humana/patologia , Criança , Pré-Escolar , Encefalite/etiologia , Feminino , Hospitais Pediátricos , Humanos , Lactente , Influenza Humana/complicações , Influenza Humana/virologia , Itália , Masculino , Orthomyxoviridae/genética , Orthomyxoviridae/isolamento & purificação , RNA Viral/líquido cefalorraquidiano , Estudos Retrospectivos , Estações do Ano , Centros de Atenção Terciária
5.
BMC Infect Dis ; 19(1): 964, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31718571

RESUMO

BACKGROUND: The aim of this study was to evaluate the correlation between clinical and imaging findings with a worse clinical outcome in patients with a confirmed diagnosis of H1N1 influenza A virus. METHODS: Patients with a positive viral test for influenza A H1N1 in 2016 and chest radiography (CR) and/or computed tomography (CT) results had clinical and imaging data reviewed. Hospitalization, admission to the intensive care unit or death were defined as worse clinical outcomes. The association between clinical and imaging features and the worse outcome was calculated in a logistical regression model. RESULTS: Eighty of 160 (50%) patients were men, with a mean age of 43 ± 19 years. The most common symptoms were as follows: flu-like symptoms 141/160 (88%), dyspnea (25/160, 17%), and thoracic pain (7/160, 5%). Abnormalities on CR were detected in 8/110 (7%) patients, and 43/59 (73%) patients had an abnormal CT. The following variables were associated with worse clinical outcomes: the presence of diabetes mellitus (DM), hypertension, dyspnea, thoracic pain, abnormal CR or CT regardless of the type of finding, CT with consolidation or ground glass opacity. CONCLUSIONS: The presence of DM, hypertension, dyspnea, thoracic pain, or an abnormal CR or CT on admission were associated with worse clinical outcomes in patients with H1N1 influenza A virus infection. Thus, the use of readily accessible clinical and imaging features on admission may have a role in the evaluation of patients with H1N1 infection.


Assuntos
Influenza Humana/diagnóstico , Adulto , Feminino , Hospitalização , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/patologia , Influenza Humana/virologia , Unidades de Terapia Intensiva , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Radiografia Torácica , Estudos Retrospectivos , Índice de Gravidade de Doença , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X
6.
PLoS Pathog ; 15(9): e1008077, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31557273

RESUMO

Influenza A virus (IAV) is a seasonal pathogen with the potential to cause devastating pandemics. IAV infects multiple epithelial cell subsets in the respiratory tract, eliciting damage to the lungs. Clearance of IAV is primarily dependent on CD8+ T cells, which must balance control of the infection with immunopathology. Using a virus expressing Cre recombinase to permanently label infected cells in a Cre-inducible reporter mouse, we previously discovered infected club cells that survive both lytic virus replication and CD8+ T cell-mediated clearance. In this study, we demonstrate that ciliated epithelial cells, type I and type II alveolar cells can also become survivor cells. Survivor cells are stable in the lung long-term and demonstrate enhanced proliferation compared to uninfected cells. When we investigated how survivor cells evade CD8+ T cell killing we observed that survivor cells upregulated the inhibitory ligand PD-L1, but survivor cells did not use PD-L1 to evade CD8+ T cell killing. Instead our data suggest that survivor cells are not inherently resistant to CD8+ T cell killing, but instead no longer present IAV antigen and cannot be detected by CD8+ T cells. Finally, we evaluate the failure of CD8+ T cells to kill these previously infected cells. This work demonstrates that additional cell types can survive IAV infection and that these cells robustly proliferate and are stable long term. By sparing previously infected cells, the adaptive immune system may be minimizing pathology associated with IAV infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Evasão da Resposta Imune , Influenza Humana/imunologia , Influenza Humana/virologia , Imunidade Adaptativa , Animais , Antígeno B7-H1/imunologia , Proliferação de Células , Sobrevivência Celular/imunologia , Citotoxicidade Imunológica , Humanos , Imunidade Celular , Vírus da Influenza A/imunologia , Vírus da Influenza A/patogenicidade , Influenza Humana/patologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptor de Morte Celular Programada 1/imunologia
7.
Cell Biochem Biophys ; 77(4): 319-333, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31559538

RESUMO

Influenza virus is known for its intermittent outbreaks affecting billions of people worldwide. Several neuraminidase inhibitors have been used in practice to overcome this situation. However, advent of new resistant mutants has limited its clinical utilization. In the recent years drug repurposing technique has attained the limelight as it is cost effective and reduces the time consumed for drug discovery. Here, we present multi-dimensional repurposing strategy that integrates the results of ligand-, energy-, receptor cavity, and shape-based pharmacophore algorithm to effectively identify novel drug candidate for influenza. The pharmacophore hypotheses were generated by utilizing the PHASE module of Schrödinger. The generated hypotheses such as AADP, AADDD, and DDRRNH, respectively, for ligand-, e-pharmacophore and receptor cavity based approach alongside shape of oseltamivir were successfully utilized to screen the DrugBank database. Subsequently, these models were evaluated for their differentiating ability using Enrichment calculation. Receiver operating curve and enrichment factors from the analysis indicate that the models possess better capability to screen actives from decoy set of molecules. Eventually, the hits retrieved from different hypotheses were subjected to molecular docking using Glide module of Schrödinger Suite. The results of different algorithms were then combined to eliminate false positive hits and to demonstrate reliable prediction performance than existing approaches. Of note, Pearson's correlation coefficients were calculated to examine the extent of correlation between the glide score and IC50 values. Further, the interaction profile, pharmacokinetic, and pharmacodynamics properties were analyzed for the hit compounds. The results from our analysis showed that alprostadil (DB00770) exhibits better binding affinity toward NA protein than the existing drug molecules. The biological activity of the hit was also predicted using PASS algorithm that renders the antiviral activity of the compound. Further, the results were validated using mutation analysis and molecular dynamic simulation studies. Indeed, this integrative filtering is able to exceed accuracy of other state-of-the-art methods for the drug discovery.


Assuntos
Descoberta de Drogas , Reposicionamento de Medicamentos , Algoritmos , Alprostadil/química , Alprostadil/metabolismo , Alprostadil/uso terapêutico , Antivirais/química , Antivirais/metabolismo , Antivirais/uso terapêutico , Sítios de Ligação , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/patologia , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Neuraminidase/química , Neuraminidase/genética , Neuraminidase/metabolismo , Oseltamivir/química , Oseltamivir/metabolismo , Ligação Proteica
8.
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
9.
Nat Commun ; 10(1): 3422, 2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31366921

RESUMO

Severe influenza infection has no effective treatment available. One of the key barriers to developing host-directed therapy is a lack of reliable prognostic factors needed to guide such therapy. Here, we use a network analysis approach to identify host factors associated with severe influenza and fatal outcome. In influenza patients with moderate-to-severe diseases, we uncover a complex landscape of immunological pathways, with the main changes occurring in pathways related to circulating neutrophils. Patients with severe disease display excessive neutrophil extracellular traps formation, neutrophil-inflammation and delayed apoptosis, all of which have been associated with fatal outcome in animal models. Excessive neutrophil activation correlates with worsening oxygenation impairment and predicted fatal outcome (AUROC 0.817-0.898). These findings provide new evidence that neutrophil-dominated host response is associated with poor outcomes. Measuring neutrophil-related changes may improve risk stratification and patient selection, a critical first step in developing host-directed immune therapy.


Assuntos
Armadilhas Extracelulares/imunologia , Influenza Humana/imunologia , Influenza Humana/patologia , Ativação de Neutrófilo/imunologia , Neutrófilos/imunologia , Ciclo Celular/imunologia , Feminino , Expressão Gênica/genética , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/imunologia , Vírus da Influenza B/isolamento & purificação , Influenza Humana/mortalidade , Pulmão/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Respiração Artificial , Insuficiência Respiratória/mortalidade , Insuficiência Respiratória/patologia , Insuficiência Respiratória/virologia
10.
Respir Res ; 20(1): 184, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416461

RESUMO

BACKGROUND: Influenza attacks the epithelium of the lung, causing cell death and disruption of the epithelial barrier leading to fluid buildup in the lung and impairment of gas exchange. Limited treatment options for severe influenza pneumonia prioritize the need for the discovery of effective therapies. IL-22 is a cytokine that promotes tissue integrity and has strong promise as a treatment option. While research has been focused on the cytokine itself, there is limited understanding of the regulation of the IL-22 receptor (IL-22Ra1) at the epithelial surface during infection. METHODS: IL-22Ra1 levels were measured by qRT-PCR, western blot and immunofluorescence following H1N1 influenza infection (A/PR/8/34 H1N1) or synthetic TLR3 mimetic, Poly (I:C). Regulation of the receptor was determined using STAT inhibitors (STAT1, STAT3 and PanSTAT inhibitors), TLR3 inhibition, and neutralization of interferon alpha receptor 2 (IFNAR2). Significance was determined by a p-value of greater than 0.05. Significance between two groups was measured using unpaired t-test and significance between more than two groups was measured using one-way ANOVA with Tukey Multiple Comparison Test. RESULTS: Here we show both in vivo and in vitro that IL-22Ra1 was induced as early as 24 h after influenza (H1N1 PR8) infection. This induction was triggered by toll-like receptor 3 (TLR3) as a TLR3 mimetic [Poly (I:C)] also induced IL-22Ra1 and inhibition of endosomal formation required for TLR3 function inhibited this process. This upregulation was dependent upon IFNß signaling through STAT1. Importantly, induction of IL-22Ra1 significantly increased IL-22 signaling as evidenced by pSTAT3 levels following IL-22 treatment. CONCLUSION: Collectively, these data suggest epithelial cells may optimize the beneficial effects of IL-22 through the induction of the IL-22 receptor during viral infection in the lung.


Assuntos
Influenza Humana/metabolismo , Receptores de Interleucina/biossíntese , Fator de Transcrição STAT1/biossíntese , Receptor 3 Toll-Like/biossíntese , Células A549 , Animais , Cloroquina/farmacologia , Humanos , Influenza Humana/patologia , Interferons/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Poli I-C/farmacologia
11.
BMC Infect Dis ; 19(1): 622, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307416

RESUMO

BACKGROUND: Cell-surface mucins are expressed in apical epithelial cells of the respiratory tract, and contribute a crucial part of the innate immune system. Despite anti-inflammatory or antiviral functions being revealed for certain cell-surface mucins such as MUC1, the roles of other mucins are still poorly understood, especially in viral infections. METHODS: To further identify mucins significant in influenza infection, we screened the expression of mucins in human nasal epithelial cells infected by H3N2 influenza A virus. RESULTS: We found that the expression of MUC15 was significantly upregulated upon infection, and specific only to active infection. While MUC15 did not interact with virus particles or reduce viral replication directly, positive correlations were observed between MUC15 and inflammatory factors in response to viral infection. Given that the upregulation of MUC15 was only triggered late into infection when immune factors (including cytokines, chemokines, EGFR and phosphorylated ERK) started to peak and plateau, MUC15 may potentially serve an immunomodulatory function later during influenza viral infection. CONCLUSIONS: Our study revealed that MUC15 was one of the few cell-surface mucins induced during influenza infection. While MUC15 did not interact directly with influenza virus, we showed that its increase coincides with the peak of immune activation and thus MUC15 may serve an immunomodulatory role during influenza infection.


Assuntos
Vírus da Influenza A Subtipo H3N2/fisiologia , Influenza Humana/patologia , Mucinas/metabolismo , Animais , Células Cultivadas , Quimiocinas/metabolismo , Citocinas/metabolismo , Cães , Células Epiteliais/classificação , Células Epiteliais/metabolismo , Receptores ErbB/metabolismo , Humanos , Influenza Humana/metabolismo , Células Madin Darby de Rim Canino , Mucinas/antagonistas & inibidores , Mucinas/genética , Cavidade Nasal/citologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Regulação para Cima , Replicação Viral/efeitos dos fármacos
12.
BMJ Case Rep ; 12(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31266755

RESUMO

Influenza myocarditis is an underappreciated and severe complication of influenza infection, estimated to be present in about 10% of all influenza cases. We present a case of a woman who precipitously died of fulminant influenza myocarditis and then review the historical data, literature and expert recommendations for suspecting and managing influenza myocarditis.


Assuntos
Influenza Humana/complicações , Influenza Humana/patologia , Miocardite/etiologia , Miocardite/patologia , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/patologia , Evolução Fatal , Feminino , Humanos , Pessoa de Meia-Idade
13.
Virus Genes ; 55(5): 592-599, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302878

RESUMO

Since February 2013, human infections with the novel influenza A H7N9 virus have occurred in eastern China. It is important to detect mutations in viral genes and analyze the clinical features of patients and viral shedding duration related to neuraminidase inhibitor (NAI) resistance. We collected clinical specimens from 31 hospitalized H7N9 patients and sequenced NA, PB2, HA, and M gene fragments. Of the 31 identified patients, 7 (22.6%) carried the R292K substitution in NA, 30 (96.8%), 3 (9.7%), and 5 (16.1%) carried E627K, Q591K, and D701N mutations in PB2, respectively, and 2 (6.5%) carried both E627K and D701N mutations in PB2. All 26 identified patients harbored Q226L mutations and possessed only a single arginine (R) at cleavage sites in the HA and a S31N mutation in M2. Among 7 NA-R292K mutated patients, 3 died and 4 were discharged. There was no significant difference in the days that patients started oseltamivir treatment after symptom onset between NA-R292K mutant and NA-R292 wild-type patients (median days, 7 vs 6, P = 0.374). NA-R292K mutant patients had a significantly longer duration of viral shedding than NA-R292 wild-type patients after oseltamivir treatment (median days, 10 vs 5, P = 0.022). The mutation of R292K in NA conferring the potential ability of oseltamivir resistance resulted in prolonged viral duration and poor outcome and should be taken into consideration in the clinical management of infected patients.


Assuntos
Antivirais/farmacologia , Farmacorresistência Viral , Subtipo H7N9 do Vírus da Influenza A/genética , Influenza Humana/virologia , Mutação de Sentido Incorreto , Oseltamivir/farmacologia , Eliminação de Partículas Virais , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Feminino , Genoma Viral , Humanos , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Influenza Humana/patologia , Masculino , Pessoa de Meia-Idade , RNA Viral/genética , Análise de Sequência de DNA
14.
Nat Microbiol ; 4(8): 1389-1400, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31110361

RESUMO

Host defence against influenza A virus (IAV) infection depends not only on host resistance to eliminate the virus, but also disease tolerance to limit lung tissue damage and maintain pulmonary function. Fatal IAV infections are frequently the result of a maladaptive immune response that compromises disease tolerance rather than host resistance to infection. Here, we show that the leukotriene B4 (LTB4)-type I interferon (IFN) axis promotes a distinct mechanism of disease tolerance to pulmonary IAV infection. We demonstrate that mice genetically deficient in LTB4 signalling (Blt1R-/-) are more susceptible to IAV infection compared to control mice, despite similar pulmonary viral loads. The increased susceptibility of Blt1R-/- mice is associated with an accumulation of inflammatory monocyte-derived macrophages (IMMs) causing increased lung immunopathology. We mechanistically define that LTB4 signalling via the BLT1 receptor enhances the activation of the type I IFN-α/ß receptor (IFNAR)/ and signal transducer and activator of transcription 1 (STAT1), which leads to IFN-α production by interstitial macrophages to suppresse in situ IMM proliferation. Importantly, the delivery of a single dose of LTB4 at the peak viral load reduces IMM proliferation, controls tissue damage and increases survival without affecting host resistance to IAV. These results reveal an unexpected anti-inflammatory role of LTB4 in disease tolerance to IAV infection.


Assuntos
Tolerância Imunológica , Imunidade Inata/imunologia , Influenza Humana/imunologia , Interferon Tipo I/metabolismo , Leucotrieno B4/metabolismo , Macrófagos/metabolismo , Animais , Morte Celular , Linhagem Celular , Proliferação de Células , Humanos , Vírus da Influenza A/imunologia , Influenza Humana/patologia , Pulmão/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/imunologia , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/metabolismo , Receptores CCR2/genética , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais
15.
Emerg Microbes Infect ; 8(1): 662-674, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31084471

RESUMO

Influenza defective interfering (DI) particles are replication-incompetent viruses carrying large internal deletion in the genome. The loss of essential genetic information causes abortive viral replication, which can be rescued by co-infection with a helper virus that possesses an intact genome. Despite reports of DI particles present in seasonal influenza A H1N1 infections, their existence in human infections by the avian influenza A viruses, such as H7N9, has not been studied. Here we report the ubiquitous presence of DI-RNAs in nasopharyngeal aspirates of H7N9-infected patients. Single Molecule Real Time (SMRT) sequencing was first applied and long-read sequencing analysis showed that a variety of H7N9 DI-RNA species were present in the patient samples and human bronchial epithelial cells. In several abundantly expressed DI-RNA species, long overlapping sequences have been identified around at the breakpoint region and the other side of deleted region. Influenza DI-RNA is known as a defective viral RNA with single large internal deletion. Beneficial to the long-read property of SMRT sequencing, double and triple internal deletions were identified in half of the DI-RNA species. In addition, we examined the expression of DI-RNAs in mice infected with sublethal dose of H7N9 virus at different time points. Interestingly, DI-RNAs were abundantly expressed as early as day 2 post-infection. Taken together, we reveal the diversity and characteristics of DI-RNAs found in H7N9-infected patients, cells and animals. Further investigations on this overwhelming generation of DI-RNA may provide important insights into the understanding of H7N9 viral replication and pathogenesis.


Assuntos
Vírus Defeituosos/genética , Subtipo H7N9 do Vírus da Influenza A/crescimento & desenvolvimento , Influenza Humana/patologia , Influenza Humana/virologia , RNA Viral/genética , Análise de Sequência de DNA , Animais , Brônquios/virologia , Vírus Defeituosos/isolamento & purificação , Modelos Animais de Doenças , Células Epiteliais/virologia , Genoma Viral , Humanos , Camundongos , Nasofaringe/patologia , Nasofaringe/virologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , RNA Viral/isolamento & purificação , Deleção de Sequência
16.
Artigo em Inglês | MEDLINE | ID: mdl-31065546

RESUMO

Objectives: Novel approaches to advance the field of vaccinology must be investigated, and are particularly of importance for influenza in order to produce a more effective vaccine. A systematic review of human challenge studies for influenza was performed, with the goal of assessing safety and ethics and determining how these studies have led to therapeutic and vaccine development. A systematic review of systems biology approaches for the study of influenza was also performed, with a focus on how this technology has been utilized for influenza vaccine development. Methods: The PubMed database was searched for influenza human challenge studies, and for systems biology studies that have addressed both influenza infection and immunological effects of vaccination. Results: Influenza human challenge studies have led to important advancements in therapeutics and influenza immunization, and can be performed safely and ethically if certain criteria are met. Many studies have investigated the use of systems biology for evaluating immune response to influenza vaccine, and several promising molecular signatures may help advance our understanding of pathogenesis and be used as targets for influenza interventions. Combining these methodologies has the potential to lead to significant advances in the field of influenza vaccinology and therapeutics. Conclusions: Human challenge studies and systems biology approaches are important tools that should be used in concert to advance our understanding of influenza infection and provide targets for novel therapeutics and immunizations.


Assuntos
Interações Hospedeiro-Patógeno , Experimentação Humana , Influenza Humana/imunologia , Orthomyxoviridae/imunologia , Orthomyxoviridae/patogenicidade , Biologia de Sistemas/métodos , Vacinologia/métodos , Descoberta de Drogas/métodos , Humanos , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/isolamento & purificação , Influenza Humana/patologia
17.
Semin Diagn Pathol ; 36(3): 152-159, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31054790

RESUMO

Lower respiratory infections remain one of the top global causes of death and the emergence of new diseases continues to be a concern. In the first two decades of the 21st century, we have born witness to the emergence of newly recognized coronaviruses that have rapidly spread around the globe, including severe acute respiratory syndrome virus (SARS) and Middle Eastern respiratory syndrome virus (MERS). We have also experienced the emergence of a novel H1N1 pandemic influenza strain in 2009 that caused substantial morbidity and mortality around the world and has transitioned into a seasonal strain. Although we perhaps most frequently think of viruses when discussing emerging respiratory infections, bacteria have not been left out of the mix, as we have witnessed an increase in the number of infections from Legionella spp. since the organisms' initial discovery in 1976. Here, we explore the basic epidemiology, clinical presentation, histopathology, and clinical laboratory diagnosis of these four pathogens and emphasize themes in humans' evolving relationship with our natural environment that have contributed to the infectious burden. Histology alone is rarely diagnostic for these infections, but has been crucial to bettering our understanding of these diseases. Together, we rely on the diagnostic acumen of pathologists to identify the clinicopathologic features that raise the suspicion of these diseases and lead to the early control of the spread in our populations.


Assuntos
Infecções por Coronavirus/patologia , Influenza Humana/patologia , Legionelose/patologia , Infecções Respiratórias/patologia , Síndrome Respiratória Aguda Grave/patologia , Infecções por Coronavirus/diagnóstico , Humanos , Influenza Humana/diagnóstico , Legionelose/diagnóstico , Infecções Respiratórias/diagnóstico , Síndrome Respiratória Aguda Grave/diagnóstico
18.
BMC Infect Dis ; 19(1): 308, 2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30947693

RESUMO

BACKGROUND: Despite World Health Organization recommendations, in many countries young children are not targeted for influenza vaccination. To help inform influenza vaccination policy, we examined the occurrence and burden of influenza in healthy children aged 6 to 35 months using data from a recent phase III placebo-controlled influenza vaccine trial conducted in countries in the Northern and Southern Hemispheres. METHODS: This was an analysis of data from participants included in the placebo arm of a phase III clinical trial in healthy children aged 6 to 35 months (EudraCT no. 2013-001231-51). Included children had never been vaccinated for influenza and were observed for one influenza season. Outcome measures included the occurrence of influenza-like illness (ILI), laboratory-confirmed influenza, virus types/subtypes, severe symptoms and complications of confirmed influenza, and healthcare use associated with confirmed influenza. RESULTS: Data from 2210 participants were analysed. ILI was reported for 811 participants (36.7%). Of these, 255 participants (31.4%) had 263 virologically confirmed episodes of influenza. The overall influenza attack rate was 11.5%. The most common influenza virus detected was A(H3N2) (40.7%), followed by B/Yamagata (23.6%), A(H1N1) (18.6%), and B/Victoria (8.0%). Grade 3 fever was reported in 24.3% of confirmed episodes, acute lower respiratory infection in 8.7%, acute otitis media in 6.1%, and pneumonia in 1.9%. In most influenza episodes (93.2%), antipyretics, analgesics, or non-steroidal anti-inflammatory drugs were taken. Antibiotics were prescribed for 41.4% of influenza episodes. More than half of the influenza episodes (57.0%) resulted in outpatient visits. Influenza resulted in overnight hospitalisation in 1.1% of episodes. CONCLUSIONS: Influenza is associated with a significant burden of disease in healthy children. This analysis also revealed that antibiotics continue to be frequently used for young children with influenza. TRIAL REGISTRATION: EudraCT no. 2013-001231-51 .


Assuntos
Influenza Humana/epidemiologia , Antibacterianos/uso terapêutico , Antipiréticos/uso terapêutico , Pré-Escolar , Efeitos Psicossociais da Doença , Feminino , Humanos , Lactente , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vacinas contra Influenza/imunologia , Influenza Humana/economia , Influenza Humana/patologia , Influenza Humana/virologia , Masculino , Efeito Placebo , RNA Viral/genética , RNA Viral/metabolismo , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/epidemiologia , Índice de Gravidade de Doença
19.
Nat Commun ; 10(1): 1629, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30967547

RESUMO

Influenza A virus has an eight-partite RNA genome that during viral assembly forms a complex containing one copy of each RNA. Genome assembly is a selective process driven by RNA-RNA interactions and is hypothesized to lead to discrete punctate structures scattered through the cytosol. Here, we show that contrary to the accepted view, formation of these structures precedes RNA-RNA interactions among distinct viral ribonucleoproteins (vRNPs), as they assemble in cells expressing only one vRNP type. We demonstrate that these viral inclusions display characteristics of liquid organelles, segregating from the cytosol without a delimitating membrane, dynamically exchanging material and adapting fast to environmental changes. We provide evidence that viral inclusions develop close to endoplasmic reticulum (ER) exit sites, depend on continuous ER-Golgi vesicular cycling and do not promote escape to interferon response. We propose that viral inclusions segregate vRNPs from the cytosol and facilitate selected RNA-RNA interactions in a liquid environment.


Assuntos
Retículo Endoplasmático/virologia , Vírus da Influenza A/fisiologia , Influenza Humana/patologia , Ribonucleoproteínas/metabolismo , Proteínas Virais/metabolismo , Montagem de Vírus , Células A549 , Animais , Citosol/metabolismo , Citosol/virologia , Cães , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Complexo de Golgi/virologia , Células HEK293 , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A/patogenicidade , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Ligação Proteica , RNA Viral/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo
20.
PLoS One ; 14(4): e0214207, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30951544

RESUMO

Respiratory diseases are a major contributor to morbidity and mortality in many tropical countries, including Lao PDR. However, little has been published regarding viral or bacterial pathogens that can contribute to influenza-like illness (ILI) in a community setting. We report on the results of a community-based surveillance that prospectively monitored the incidence of ILI and its causative pathogens in Vientiane capital in Lao PDR. A cohort of 995 households, including 4885 study participants, were followed-up between May 2015 and May 2016. Nasopharyngeal swabs, throat swabs, and sputum specimens were collected from ILI cases identified through active case-finding. Real-Time PCR was used to test nasopharyngeal swabs for 21 respiratory pathogens, while throat and sputum samples were subjected to bacterial culture. Generalized linear mixed models were used to assess potential risk factors for associations with ILI. In total, 548 episodes of ILI were reported among 476 (9.7%) of the study participants and 330 (33.2%) of the study households. The adjusted estimated incidence of ILI within the study area was 10.7 (95%CI: 9.4-11.9) episodes per 100 person-years. ILI was significantly associated with age group (p<0.001), sex (p<0.001), and number of bedrooms (p = 0.04) in multivariate analysis. In 548 nasopharyngeal swabs, the most commonly detected potential pathogens were Streptococcus pneumoniae (17.0%), Staphylococcus aureus (11.3%), influenza A (11.1%; mostly subtype H3N2), rhinovirus (7.5%), and influenza B (8.0%). Streptococci were isolated from 42 (8.6%) of 536 throat swabs, most (27) of which were Lancefield Group G. Co-infections were observed in 132 (24.1%) of the 548 ILI episodes. Our study generated valuable data on respiratory disease burden and patterns of etiologies associated with community-acquired acute respiratory illness Laos. Establishment of a surveillance strategy in Laos to monitor trends in the epidemiology and burden of acute respiratory infections is required to minimize their impact on human health.


Assuntos
Vírus da Influenza A Subtipo H3N2/patogenicidade , Influenza Humana/epidemiologia , Infecções Respiratórias/epidemiologia , Rhinovirus/patogenicidade , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Características da Família , Feminino , Humanos , Lactente , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/diagnóstico , Influenza Humana/patologia , Influenza Humana/virologia , Laos/epidemiologia , Masculino , Pessoa de Meia-Idade , Faringe/patologia , Faringe/virologia , Reação em Cadeia da Polimerase em Tempo Real , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/patologia , Infecções Respiratórias/virologia
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