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1.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(11): 1035-1041, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31879001

RESUMO

Objective To prepare the monoclonal antibodies specifically against P protein of human respiratory syncytial virus (HRSV) and identify it. Methods HRSV P protein prepared by prokaryotic expression in the form of overlapping peptides was used as the immunogen, and monoclonal antibodies (mAbs) were screened by hybridoma technology. Western blot analysis was used to verify the binding activity of the screened mAbs and P protein, and immunofluorescence cytochemical staining was used to determine whether the obtained mAbs could be used to detect the expression of P protein in HEp-2 cells infected with HRSV. Results P181-15A3 and P211-16D8 with great reactivity and specific recognition of HRSV P protein were screened. Both mAbs could bind to P protein by Western blot analysis and could be used for immunocytochemical detection of P protein in HEp-2 cells after HRSV infection. Conclusion We have successfully prepared the mAbs against HRSV P protein.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Vírus Sincicial Respiratório Humano , Proteínas Estruturais Virais/imunologia , Animais , Western Blotting , Humanos , Hibridomas , Imuno-Histoquímica , Camundongos
2.
Internist (Berl) ; 60(11): 1146-1150, 2019 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-31486858

RESUMO

Respiratory syncytial virus (RSV) is worldwide a very important virus leading to infection of the respiratory system. In particular preterm babies, infants and elderly adults are prone to developing severe diseases such as bronchiolitis or pneumonia, which require intensive care and cause increased mortality. Although RSV is rapidly detected, preventive and therapeutic measures are limited. New antivirals are already in clinical trials.


Assuntos
Antivirais/administração & dosagem , Bronquiolite/diagnóstico , Bronquiolite/prevenção & controle , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sincicial Respiratório Humano/isolamento & purificação , Adulto , Idoso , Antivirais/uso terapêutico , Bronquiolite/tratamento farmacológico , Bronquiolite/virologia , Bronquiolite Viral/diagnóstico , Bronquiolite Viral/virologia , Humanos , Lactente , Recém-Nascido , Pneumonia/diagnóstico , Pneumonia/virologia , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/imunologia , Fatores de Risco
3.
Mol Biol (Mosk) ; 53(4): 541-560, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31397431

RESUMO

The human respiratory syncytial virus (RSV) is one of the most common viral pathogens that affects the lower respiratory tract and could be a reason of bronchiolitis and/or pneumonia. Currently, there are no available effective ways of treating the RSV infection. Attempts to develop preventive vaccine have been unsuccessful. The only therapeutic agent used for RSV treatment is virazole (ribavirin); however, it induces adverse effects. Medications based on neutralizing monoclonal antibodies, such as IGIV (Respigam), palivizumab (Synagis), and MEDI-524 (Numab), are under clinical trials; however, their use will be limited by their high cost. One of the promising approaches for antiviral therapy is the use of natural peptides (defensins and cathelicidins), or their synthetic analogs. The majority of currently described antiviral peptides are developed against the human immunodeficiency virus, the herpes simplex virus, and the influenza virus. At the same time, a body of experimental data evidencing anti-RSV activity of peptides has been accumulated. The main advantages of peptide drugs are their wide spectrum of antiviral activity and low toxicity. However, there are obstacles in implementing peptide-based drugs in clinical practice. Due to their low resistance to the action of serum proteases, most authors consider peptides promising only for local application. Given that RSV affects the epithelium of the respiratory tract, where the protease activity is lower than in the systemic circulation, it is possible to develop locally active peptide drugs, for example, as inhalation forms. Their stability could also be increased by the synthesis of dendrimer peptides and by the development of recombinant peptides as precursor proteins. Anti-RSV peptides can be divided into several groups: (1) attachment and/or fusion blockers; (2) peptides displaying direct virucidal activity, disrupting the viral envelope. Such peptides, which suppress early stages of the viral life cycle, are considered prophylactic agents. However, for several peptides, their immunoregulatory properties have been described, which opens the possibility for therapeutic use. This review summarizes the information on the antiviral properties of such peptides and mechanisms of their action and describes the prospects of the future development of antiviral peptides.


Assuntos
Antivirais/farmacologia , Peptídeos/farmacologia , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Antivirais/uso terapêutico , Humanos , Peptídeos/uso terapêutico
4.
Rev Soc Bras Med Trop ; 52: e20180249, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365620

RESUMO

INTRODUCTION: Prevalence of influenza A virus (Flu-A), respiratory syncytial virus (RSV), and human metapneumovirus (hMPV) was assessed in children with acute respiratory infections (ARIs). METHODS: Nasopharyngeal aspirates and throat swabs were subjected to real-time polymerase chain reaction (PCR) to detect RSV and Flu-A and to conventional PCR to detect hMPV. RESULTS: Of the 156 children assessed, 93 (59.6%) carried at least one virus, with 35.9% positive for RSV, 14.1% for hMPV, and 9.6% for Flu-A. The prevalence of co-infections was 2.6%. CONCLUSIONS: The high detection rate may reflect increased sensitivity of real-time PCR compared to traditional PCR and viral culture.


Assuntos
Influenza Humana/epidemiologia , Infecções por Paramyxoviridae/epidemiologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções Respiratórias/virologia , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Vírus da Influenza A/genética , Irã (Geográfico)/epidemiologia , Masculino , Metapneumovirus/genética , Nasofaringe/virologia , Reação em Cadeia da Polimerase em Tempo Real , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/epidemiologia
5.
Comp Immunol Microbiol Infect Dis ; 65: 213-218, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31300116

RESUMO

Human respiratory syncytial virus (hRSV) is the most important respiratory pathogen in young children worldwide. Experimental modelling of hRSV disease by bovine RSV (bRSV) infection in calves provides an important tool for developing new strategies for prevention and treatment. Depending on the scientific hypothesis under investigation, this cognate host-virus model might have the disadvantage of using a highly related but not genetically identical virus. In this study, we aim to describe viral kinetics and (clinical) disease characteristics in calves inoculated with hRSV. Our results show that hRSV infects the upper and, to a lesser extent, the lower respiratory tract of calves. Infection causes upper airway clinical disease symptoms and neutrophilic infiltration of the lower airways. We conclude that a hRSV model in calves may aid future research involving distinct scientific questions related to hRSV disease in children.


Assuntos
Modelos Animais de Doenças , Interações entre Hospedeiro e Microrganismos , Infecções por Vírus Respiratório Sincicial/veterinária , Vírus Sincicial Respiratório Bovino/fisiologia , Vírus Sincicial Respiratório Humano/fisiologia , Infecções Respiratórias/veterinária , Fatores Etários , Animais , Bovinos , Feminino , Humanos , Cinética , Pulmão/imunologia , Pulmão/virologia , Masculino , Projetos Piloto , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/virologia
6.
BMC Infect Dis ; 19(1): 613, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299924

RESUMO

BACKGROUND: The Respiratory Syncytial Virus (RSV) A genotype ON1, which was first detected in Ontario (Canada) in 2010/11, appeared in Germany in 2011/12. Preliminary observations suggested a higher clinical severity in children infected with this new genotype. We investigated spread and disease severity of RSV-A ON1 in pediatric in- and outpatient settings. METHODS: During 2010/11 to 2016/17, clinical characteristics and respiratory samples from children with acute respiratory tract infections (RTI) were obtained from ongoing surveillance studies in 33 pediatric practices (PP), one pediatric hospital ward (PW) and 23 pediatric intensive care units (PICU) in Germany. RSV was detected in the respiratory samples by PCR; genotypes were identified by sequencing. Within each setting, clinical severity markers were compared between RSV-A ON1 and RSV-A non-ON1 genotypes. RESULTS: A total of 603 children with RSV-RTI were included (132 children in PP, 288 in PW, and 183 in PICU). Of these children, 341 (56.6%) were infected with RSV-A, 235 (39.0%) with RSV-B, and one child (0.2%) with both RSV-A and RSV-B; in 26 (4.3%) children, the subtype could not be identified. In the 341 RSV-A positive samples, genotype ON1 was detected in 247 (72.4%), NA1 in 92 (26.9%), and GA5 in 2 children (0.6%). RSV-A ON1, rarely observed in 2011/12, was the predominant RSV-A genotype in all settings by 2012/13 and remained predominant until 2016/17. Children in PP or PW infected with RSV-A ON1 did not show a more severe clinical course of disease compared with RSV-A non-ON1 infections. In the PICU group, hospital stay was one day longer (median 8 days, inter-quartile range (IQR) 7-12 vs. 7 days, IQR 5-9; p = 0.02) and duration of oxygen treatment two days longer (median 6 days, IQR 4-9 vs. 4 days, IQR 2-6; p = 0.03) for children infected with RSV-A ON1. CONCLUSIONS: In children, RSV-A ON1 largely replaced RSV-A non-ON1 genotypes within two seasons and remained the predominant RSV-A genotype in Germany during subsequent seasons. A higher clinical severity of RSV-A ON1 was observed within the group of children receiving PICU treatment, whereas in other settings clinical severity of RSV-A ON1 and non-ON1 genotypes was largely similar.


Assuntos
Infecções por Vírus Respiratório Sincicial/patologia , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/patologia , Pré-Escolar , Feminino , Genótipo , Alemanha/epidemiologia , Hospitais Pediátricos , Humanos , Lactente , Unidades de Terapia Intensiva Pediátrica , Tempo de Internação , Masculino , Filogenia , RNA Viral/metabolismo , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Estações do Ano , Índice de Gravidade de Doença
7.
BMC Public Health ; 19(1): 807, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31234829

RESUMO

BACKGROUND: Human metapneumovirus (HMPV) have similar symptoms to those caused by the respiratory syncytial virus (RSV). The modes of transmission and dynamics of time series data still remain poorly understood. Climatic factors have long been suspected to be implicated in impacting on the number of cases for these epidemics. Currently, only a few models satisfactorily capture the dynamics of time series data of these two viruses. Our objective was to assess the presence of influence of high incidences between the viruses and to ascertain whether higher incidences of one virus are influenced by the other. METHODS: In this study, we used a negative binomial model to investigate the relationship between RSV and HMPV while adjusting for climatic factors. We specifically aimed at establishing the heterogeneity in the autoregressive effect to account for the influence between these viruses. RESULTS: In this study, our findings showed that RSV incidence contributed to the severity of HMPV incidence. This was achieved through comparison of 12 models with different structures, including those with and without interaction between climatic factors. The models with climatic factors out-performed those without. CONCLUSIONS: The study has improved our understanding of the dynamics of RSV and HMPV in relation to climatic cofactors thereby setting a platform to devise better intervention measures to combat the epidemics. We conclude that preventing and controlling RSV infection subsequently reduces the incidence of HMPV.


Assuntos
Metapneumovirus , Modelos Estatísticos , Infecções por Paramyxoviridae/epidemiologia , Vigilância da População/métodos , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Humano , Teorema de Bayes , Clima , Epidemias , Feminino , Humanos , Incidência , Quênia/epidemiologia , Masculino , Infecções por Paramyxoviridae/virologia , Infecções por Vírus Respiratório Sincicial/virologia
8.
Infect Dis Health ; 24(3): 147-151, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31160245

RESUMO

BACKGROUND: Influenza-like illness is often caused by respiratory viral infections, and is a frequent cause of presentation to hospital. Rapid diagnostics for respiratory viruses, with turnaround times of less than sixty minutes, are increasingly available. Early physician knowledge of positive respiratory virus tests has previously been shown to impact patient care in a paediatric population but hasn't been evaluated in adults. METHODS: Rapid testing for the respiratory viruses Influenza A, Influenza B and respiratory syncytial virus (RSV) was introduced in our institution in 2018. This reduced turnaround time for tests from more than 24 h, to 1-10 h depending on time of day. A retrospective cohort study was performed on patients presenting with influenza-like illness, in whom a nasopharyngeal swab for respiratory viruses was requested. Data was collected before and after the introduction of the rapid assay. Outcomes included antibiotic use (less or more than 24 h) and length of hospital stay (less or more than 24 h). RESULTS: In all patients who tested positive for a respiratory virus, there was an association between rapid testing and less antibiotic use. This was largely driven by paediatric cases; there was no change in prescribing for adult patients. There was no impact on timing of patient discharge. CONCLUSIONS: Rapid testing for respiratory viruses has a potentially useful role in antimicrobial stewardship. It is unclear why earlier knowledge of positive viral test didn't lead to less antibiotics in adults. This study showed no impact of rapid testing on time to patient discharge.


Assuntos
Antibacterianos/uso terapêutico , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Tempo de Internação , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/diagnóstico , Adulto , Gestão de Antimicrobianos , Criança , Estudos de Coortes , Humanos , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/virologia , Estudos Retrospectivos , Centros de Atenção Terciária , Fatores de Tempo
9.
Arch Virol ; 164(9): 2231-2241, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31177351

RESUMO

Viral persistence alters cellular antiviral activities. Nitric oxide (NO), a highly reactive free radical and a potent antiviral molecule, can inhibit replication of RNA and DNA viruses, but its production and effect during viral persistence are largely unknown. NO synthesis is stimulated in epithelial cells during acute infection with respiratory syncytial virus (RSV) and interferes with viral replication. In this study, we compared the levels of production of NO and expression of its regulatory enzymes, inducible nitric oxide synthase (NOS II) and arginase 1 (Arg-1), during acute and persistent RSV infection in a macrophage cell line to investigate their role in the control and maintenance of viral infection. We observed that NO and NOS II mRNA were induced at higher levels in acutely infected macrophages than in persistently infected macrophages, while the kinetics of NOS II protein expression were similar in both types of infected cultures, except that its disappearance was delayed during acute infection. Thus, NOS II was inducible and expressed at high levels during persistent infection, but production of NO was low relative to acute infection. This was not associated with a lack of enzymatic activity but instead was due to constitutive expression of the Arg-1 enzyme at the mRNA and protein levels, suggesting that arginase restricts availability of L-arginine as a substrate for NOS II to synthesize NO. This hypothesis was supported by showing that arginase enzymatic activity was inhibited in persistently RSV-infected cells by Nω-hydroxy-nor-L-arginine, increasing L-arginine availability in conditioned medium and producing increased levels of nitrites, concurrently with a significant reduction in virus genome replication, implying that Arg-1 overexpression contributes to the maintenance of the RSV genome in the host in persistent infection.


Assuntos
Arginase/metabolismo , Óxido Nítrico/metabolismo , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/fisiologia , Arginase/genética , Arginina/metabolismo , Regulação para Baixo , Humanos , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Nitritos/metabolismo , Infecções por Vírus Respiratório Sincicial/enzimologia , Infecções por Vírus Respiratório Sincicial/genética , Vírus Sincicial Respiratório Humano/genética , Replicação Viral
10.
J Glob Health ; 9(1): 010425, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31131100

RESUMO

Background: The high disease burden of respiratory syncytial virus (RSV) infection and renewed focus on developing a vaccine has led to sustained interest in published RSV-related research. The majority of this research comes from Europe and North/Central America and this landscape review aimed to identify and characterize RSV-related research published during 2011-2015 in these geographical areas. Methods: We conducted a literature review on electronic databases Scopus and Web of Science to identify published studies investigating RSV throughout Europe and North/Central America. We stratified RSV-related publications between 2011-2015 by study type, country, research institution and funding body. Results: The annual published output of RSV-related research has increased by 29% over the period 2011-2015. Eighty seven percent (13/15) of the most highly cited papers on RSV during this period were from North America. US universities with the highest number of RSV-related publications included Emory (n = 23), Vanderbilt (n = 23), University of Michigan (n = 21) and Ohio State (n = 20). The UK (n = 125), Netherlands (n = 97) and Spain (n = 76) were major European contributors to RSV-related publications. University Medical Centre Utrecht (n = 40) and Imperial College London (n = 28) were the European universities with the largest number of RSV-related publications. The National Institutes of Health provided funding for one quarter of all RSV-related publications. However, few countries in Eastern Europe, Central America and the Caribbean published RSV-related research. Few epidemiological studies focused on adult populations over 18 years old (n = 28, 7%) with only five publications specifically investigating elderly populations over 65. Conclusions: This review identifies key regions and research institutions which contributed to RSV-related research during 2011-2015 as well as the donor agencies which supported this research. Further research investment is required in a number of countries. More research in the elderly and in high-risk adults is required given the lack of studies pertaining to these populations. Researchers and those commissioning research can use the data from this review to identify productive research institutions and geographical gaps in RSV research.


Assuntos
Pesquisa Biomédica/estatística & dados numéricos , Publicações/estatística & dados numéricos , Vírus Sincicial Respiratório Humano , América Central , Europa (Continente) , Humanos , América do Norte
11.
Nat Commun ; 10(1): 2218, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101811

RESUMO

RSV infection is typically associated with secondary bacterial infection. We hypothesise that the local airway immune response to RSV has incidental antibacterial effects. Using coordinated proteomics and metagenomics analysis we simultaneously analysed the microbiota and proteomes of the upper airway and determined direct antibacterial activity in airway secretions of RSV-infected children. Here, we report that the airway abundance of Streptococcus was higher in samples collected at the time of RSV infection compared with samples collected one month later. RSV infection is associated with neutrophil influx into the airway and degranulation and is marked by overexpression of proteins with known antibacterial activity including BPI, EPX, MPO and AZU1. Airway secretions of children infected with RSV, have significantly greater antibacterial activity compared to RSV-negative controls. This RSV-associated, neutrophil-mediated antibacterial response in the airway appears to act as a regulatory mechanism that modulates bacterial growth in the airways of RSV-infected children.


Assuntos
Infecções Bacterianas/imunologia , Neutrófilos/imunologia , Mucosa Respiratória/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Infecções Bacterianas/microbiologia , Degranulação Celular/imunologia , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Quênia , Metagenômica/métodos , Microbiota/imunologia , Proteômica/métodos , Mucosa Respiratória/citologia , Mucosa Respiratória/microbiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Streptococcus/imunologia , Streptococcus/isolamento & purificação
12.
Nat Commun ; 10(1): 2105, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-31068578

RESUMO

The respiratory syncytial virus (RSV) F glycoprotein is a class I fusion protein that mediates viral entry and is a major target of neutralizing antibodies. Structures of prefusion forms of RSV F, as well as other class I fusion proteins, have revealed compact trimeric arrangements, yet whether these trimeric forms can transiently open remains unknown. Here, we perform structural and biochemical studies on a recently isolated antibody, CR9501, and demonstrate that it enhances the opening of prefusion-stabilized RSV F trimers. The 3.3 Å crystal structure of monomeric RSV F bound to CR9501, combined with analysis of over 25 previously determined RSV F structures, reveals a breathing motion of the prefusion conformation. We also demonstrate that full-length RSV F trimers transiently open and dissociate on the cell surface. Collectively, these findings have implications for the function of class I fusion proteins, as well as antibody prophylaxis and vaccine development for RSV.


Assuntos
Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Vírus Sincicial Respiratório Humano/fisiologia , Proteínas Virais de Fusão/metabolismo , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Linfócitos B/virologia , Simulação por Computador , Cristalografia por Raios X , Desenvolvimento de Medicamentos , Células HEK293 , Células HeLa , Humanos , Modelos Moleculares , Multimerização Proteica/fisiologia , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/virologia , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Células Vero , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/imunologia
13.
Arch Virol ; 164(7): 1843-1850, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31053978

RESUMO

Human respiratory syncytial virus (RSV) is a common viral pathogen that causes lower respiratory tract infections in infants and children globally. In this study, we developed a duplex reverse transcription recombinase-aided amplification (duplex-rtRAA) assay containing an internal control in a single closed tube for the detection of human RSV. The internal control in the amplification effectively eliminated false-negative results and ensured the accuracy of the duplex-rtRAA system. We first developed and evaluated a universal singleplex-rtRAA assay for RSV. The sensitivity of this assay for RSV was determined as 4.4 copies per reaction, and the specificity was 100%. Next, a duplex-rtRAA assay with an internal control was established. The sensitivity of the duplex-rtRAA assay approached 5.0 copies per reaction, and no cross-reaction with other common respiratory viruses was observed. The two detection methods (singleplex-rtRAA and duplex-rtRAA) developed in this study were used to test 278 clinical specimens, and the results showed absolute consistency with RSV RT-qPCR analysis, demonstrating 100% diagnostic sensitivity and specificity. These data indicate that the duplex-rtRAA has great potential for the rapid detection of RSV with a high sensitivity.


Assuntos
Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA Viral/análise , Infecções por Vírus Respiratório Sincicial/diagnóstico , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/diagnóstico , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Recombinases , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/virologia , Transcrição Reversa , Sensibilidade e Especificidade
14.
Nat Commun ; 10(1): 2331, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133680

RESUMO

Artificial nanoparticles accumulate a protein corona layer in biological fluids, which significantly influences their bioactivity. As nanosized obligate intracellular parasites, viruses share many biophysical properties with artificial nanoparticles in extracellular environments and here we show that respiratory syncytial virus (RSV) and herpes simplex virus type 1 (HSV-1) accumulate a rich and distinctive protein corona in different biological fluids. Moreover, we show that corona pre-coating differentially affects viral infectivity and immune cell activation. In addition, we demonstrate that viruses bind amyloidogenic peptides in their corona and catalyze amyloid formation via surface-assisted heterogeneous nucleation. Importantly, we show that HSV-1 catalyzes the aggregation of the amyloid ß-peptide (Aß42), a major constituent of amyloid plaques in Alzheimer's disease, in vitro and in animal models. Our results highlight the viral protein corona as an acquired structural layer that is critical for viral-host interactions and illustrate a mechanistic convergence between viral and amyloid pathologies.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Herpesvirus Humano 1/patogenicidade , Interações Hospedeiro-Patógeno/imunologia , Fragmentos de Peptídeos/metabolismo , Coroa de Proteína/imunologia , Vírus Sincicial Respiratório Humano/patogenicidade , Doença de Alzheimer/imunologia , Doença de Alzheimer/patologia , Doença de Alzheimer/virologia , Animais , Líquido da Lavagem Broncoalveolar/virologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Voluntários Saudáveis , Herpes Simples/sangue , Herpes Simples/imunologia , Herpes Simples/patologia , Herpesvirus Humano 1/imunologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Agregados Proteicos/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/patologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/imunologia , Células Vero
17.
MBio ; 10(3)2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064833

RESUMO

Infectious viruses so precisely fit their hosts that the study of natural viral infection depends on host-specific mechanisms that affect viral infection. For human parainfluenza virus 3, a prevalent cause of lower respiratory tract disease in infants, circulating human viruses are genetically different from viruses grown in standard laboratory conditions; the surface glycoproteins that mediate host cell entry on circulating viruses are suited to the environment of the human lung and differ from those of viruses grown in cultured cells. Polarized human airway epithelium cultures have been used to represent the large, proximal airways of mature adult airways. Here we modeled respiratory virus infections that occur in children or infect the distal lung using lung organoids that represent the entire developing infant lung. These 3D lung organoids derived from human pluripotent stem cells contain mesoderm and pulmonary endoderm and develop into branching airway and alveolar structures. Whole-genome sequencing analysis of parainfluenza viruses replicating in the organoids showed maintenance of nucleotide identity, suggesting that no selective pressure is exerted on the virus in this tissue. Infection with parainfluenza virus led to viral shedding without morphological changes, while respiratory syncytial virus infection induced detachment and shedding of infected cells into the lung organoid lumens, reminiscent of parainfluenza and respiratory syncytial virus in human infant lungs. Measles virus infection, in contrast, induced syncytium formation. These human stem cell-derived lung organoids may serve as an authentic model for respiratory viral pathogenesis in the developing or infant lung, recapitulating respiratory viral infection in the host.IMPORTANCE Respiratory viruses are among the first pathogens encountered by young children, and the significant impact of these viral infections on the developing lung is poorly understood. Circulating viruses are suited to the environment of the human lung and are different from those of viruses grown in cultured cells. We modeled respiratory virus infections that occur in children or infect the distal lung using lung organoids that represent the entire developing infant lung. These 3D lung organoids, derived from human pluripotent stem cells, develop into branching airway and alveolar structures and provide a tissue environment that maintains the authentic viral genome. The lung organoids can be genetically engineered prior to differentiation, thereby generating tissues bearing or lacking specific features that may be relevant to viral infection, a feature that may have utility for the study of host-pathogen interaction for a range of lung pathogens.


Assuntos
Células Epiteliais Alveolares/virologia , Pulmão/virologia , Organoides/virologia , Vírus da Parainfluenza 3 Humana/patogenicidade , Células-Tronco Pluripotentes/virologia , Infecções por Respirovirus/patologia , Diferenciação Celular , Células Cultivadas , Genoma Viral , Humanos , Lactente , Pulmão/citologia , Pulmão/patologia , Vírus do Sarampo/patogenicidade , Vírus da Parainfluenza 3 Humana/genética , Vírus Sincicial Respiratório Humano/patogenicidade , Internalização do Vírus , Sequenciamento Completo do Genoma
18.
BMC Public Health ; 19(1): 499, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053069

RESUMO

BACKGROUND: Acute respiratory infection (ARI) is an important cause of mortality in children and adults. However, studies assessing risk factors for ARI-related deaths in low- and middle-income settings are limited. We describe ARI-related death and associated factors among children aged < 2 years and adults aged ≥18 years hospitalized with ARI in Guatemala. METHODS: We used respiratory illness surveillance data in Guatemala from 2007 to 2013. ARI was defined as evidence of acute infection and ≥ 1 sign/symptom of respiratory disease in hospitalized patients. Clinical, sociodemographic, and follow-up data were gathered. Nasopharyngeal/oropharyngeal swabs were collected from patients with ARI and tested for 6 respiratory viruses; urine was collected only from adults with ARI and tested for pneumococcal antigen. Blood cultures and chest radiographs were performed at the physician's discretion. Radiographs were interpreted per World Health Organization guidelines to classify endpoint pneumonia (i.e. suggestive of bacterial pneumonia). Multivariable logistic regression was used to compare characteristics of patients with fatal cases, including those who died in-hospital or were discharged in a moribund state, with those of patients with non-fatal cases. RESULTS: Among 4109 ARI cases identified in hospitalized children < 2 years old, 174 (4%) were fatal. Median age at admission was 4 and 6 months for children with fatal and non-fatal cases, respectively. Factors associated with fatality included low weight-for-age, low family income, heart disease, and endpoint pneumonia; breastfeeding and respiratory syncytial virus (RSV) detection were negatively associated with fatality. Among 1517 ARI cases identified in hospitalized adults ≥18 years, 181 (12%) episodes were fatal. Median age at admission was 57 years for adults with fatal and non-fatal cases. Low body mass index, male sex, kidney disease, and endpoint pneumonia were significantly more common among patients with fatal versus non-fatal cases. CONCLUSIONS: Our findings highlight some of the factors that must be addressed in order to reduce ARI-related mortality, including promotion of good nutrition, breastfeeding, management and prevention of chronic comorbidities, and poverty reduction. Although no specific pathogen increased risk for death, endpoint pneumonia was significantly associated with fatality, suggesting that the pneumococcal conjugate vaccine could contribute to future reductions in ARI-related mortality.


Assuntos
Hospitalização/estatística & dados numéricos , Pneumonia Bacteriana/mortalidade , Infecções Respiratórias/mortalidade , Adulto , Pré-Escolar , Feminino , Guatemala/epidemiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Vacinas Pneumocócicas , Pneumonia Bacteriana/diagnóstico , Pneumonia Bacteriana/terapia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/terapia , Adulto Jovem
19.
mSphere ; 4(2)2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31019002

RESUMO

Human respiratory syncytial virus (RSV) is a major cause of severe respiratory disease in (premature) newborns and causes respiratory illness in the elderly. Different monoclonal antibody (MAb) and vaccine candidates are in development worldwide and will hopefully become available within the near future. To implement such RSV vaccines, adequate decisions about immunization schedules and the different target group(s) need to be made, for which the assessment of antibody levels against RSV is essential. To survey RSV antigen-specific antibody levels, we developed a serological multiplex immunoassay (MIA) that determines and distinguishes antibodies against the five RSV glycoproteins postfusion F, prefusion F, Ga, Gb, and N simultaneously. The standardized RSV pentaplex MIA is sensitive, highly reproducible, and specific for the five RSV proteins. The preservation of the conformational structure of the immunodominant site Ø of prefusion F after conjugation to the beads has been confirmed. Importantly, good correlation is obtained between the microneutralization test and the MIA for all five proteins, resulting in an arbitrarily chosen cutoff value of prefusion F antibody levels for seropositivity in the microneutralization assay. The wide dynamic range requiring only two serum sample dilutions makes the RSV-MIA a high-throughput assay very suitable for (large-scale) serosurveillance and vaccine clinical studies.IMPORTANCE In view of vaccine and monoclonal development to reduce hospitalization and death due to lower respiratory tract infection caused by RSV, assessment of antibody levels against RSV is essential. This newly developed multiplex immunoassay is able to measure antibody levels against five RSV proteins simultaneously. This can provide valuable insight into the dynamics of (maternal) antibody levels and RSV infection in infants and toddlers during the first few years of life, when primary RSV infection occurs.


Assuntos
Anticorpos Antivirais/análise , Imunoensaio/métodos , Imunoensaio/normas , Infecções por Vírus Respiratório Sincicial/imunologia , Proteínas Virais/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Vírus Sincicial Respiratório Humano , Sensibilidade e Especificidade
20.
Virus Res ; 266: 58-68, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31004621

RESUMO

Respiratory syncytial virus (RSV) is a leading cause of infant hospitalization worldwide each year and there is presently no licensed vaccine to prevent severe RSV infections. Two major RSV glycoproteins, attachment (G) and fusion (F) protein, regulate viral replication and both proteins contain potential glycosylation sites which are highly variable for the G protein and conserved for the F protein among virus isolates. The RSV F sequence possesses five N-glycosylation sites located in the F2 subunit (N27 and N70), the p27 peptide (N116 and N126) and the F1 subunit (N500). The importance of RSV F N-glycosylation in virus replication and immunogenicity is not yet fully understood, and a better understanding may provide new insights for vaccine development. By using a BAC-based reverse genetics system, recombinant viruses expressing F proteins with loss of N-glycosylation sites were made. Mutant viruses with single N-glycosylation sites removed could be recovered, while this was not possible with the mutant with all N-glycosylation sites removed. Although the individual RSV F N-glycosylation sites were shown not to be essential for viral replication, they do contribute to the efficiency of in vitro and in vivo viral infection. To evaluate the role of N-glycosylation sites on RSV F antigenicity, serum antibody titers were determined after infection of BALB/c mice with RSV expressing the glycomutant F proteins. Infection with recombinant virus lacking the N-glycosylation site at position N116 (RSV F N116Q) resulted in significant higher neutralizing antibody titers compared to RSV F WT infection, which is surprising since this N-glycan is present in the p27 peptide which is assumed to be absent from the mature F protein in virions. Thus, single or combined RSV F glycomutations which affect virus replication and fusogenicity, and which may induce enhanced antibody responses upon immunization could have the potential to improve the efficacy of RSV LAV approaches.


Assuntos
Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/fisiologia , Vírus Sincicial Respiratório Humano/patogenicidade , Proteínas Virais de Fusão/metabolismo , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Linhagem Celular Tumoral , Feminino , Células Gigantes/virologia , Glicosilação , Humanos , Imunização , Imunogenicidade da Vacina , Camundongos Endogâmicos BALB C , Mutação , Infecções por Vírus Respiratório Sincicial/metabolismo , Infecções por Vírus Respiratório Sincicial/patologia , Vírus Sincicial Respiratório Humano/crescimento & desenvolvimento , Vírus Sincicial Respiratório Humano/imunologia , Células Vero , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologia , Replicação Viral
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