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1.
Front Immunol ; 13: 970325, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36059535

RESUMO

Viral cross-species transmission is recognized to be a major threat to both human and animal health, however detailed information on determinants underlying virus host tropism and susceptibility is missing. Influenza C and D viruses (ICV, IDV) are two respiratory viruses that share up to 50% genetic similarity, and both employ 9-O-acetylated sialic acids to enter a host cell. While ICV infections are mainly restricted to humans, IDV possesses a much broader host tropism and has shown to have a zoonotic potential. This suggests that additional virus-host interactions play an important role in the distinct host spectrum of ICV and IDV. In this study, we aimed to characterize the innate immune response of the respiratory epithelium of biologically relevant host species during influenza virus infection to identify possible determinants involved in viral cross-species transmission. To this end, we performed a detailed characterization of ICV and IDV infection in primary airway epithelial cell (AEC) cultures from human, porcine, and bovine origin. We monitored virus replication kinetics, cellular and host tropism, as well as the host transcriptional response over time at distinct ambient temperatures. We observed that both ICV and IDV predominantly infect ciliated cells, independently from host and temperature. Interestingly, temperature had a profound influence on ICV replication in both porcine and bovine AEC cultures, while IDV replicated efficiently irrespective of temperature and host. Detailed time-resolved transcriptome analysis revealed both species-specific and species uniform host responses and highlighted 34 innate immune-related genes with clear virus-specific and temperature-dependent profiles. These data provide the first comprehensive insights into important common and species-specific virus-host dynamics underlying the distinct host tropism of ICV and IDV, as well as possible determinants involved in viral cross-species transmission.


Assuntos
Doenças Transmissíveis , Influenza Humana , Infecções por Orthomyxoviridae , Orthomyxoviridae , Thogotovirus , Animais , Bovinos , Humanos , Imunidade Inata , Mucosa Respiratória , Suínos , Thogotovirus/genética
2.
Front Immunol ; 13: 958801, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36091002

RESUMO

Fatal influenza (flu) virus infection often activates excessive inflammatory signals, leading to multi-organ failure and death, also referred to as cytokine storm. PPARγ (Peroxisome proliferator-activated receptor gamma) agonists are well-known candidates for cytokine storm modulation. The present study identified that influenza infection reduced PPARγ expression and decreased PPARγ transcription activity in human alveolar macrophages (AMs) from different donors. Treatment with PPARγ agonist Troglitazone ameliorated virus-induced proinflammatory cytokine secretion but did not interfere with the IFN-induced antiviral pathway in human AMs. In contrast, PPARγ antagonist and knockdown of PPARγ in human AMs further enhanced virus-stimulated proinflammatory response. In a mouse model of influenza infection, flu virus dose-dependently reduced PPARγ transcriptional activity and decreased expression of PPARγ. Moreover, PPARγ agonist troglitazone significantly reduced high doses of influenza infection-induced lung pathology. In addition, flu infection reduced PPARγ expression in all mouse macrophages, including AMs, interstitial macrophages, and bone-marrow-derived macrophages but not in alveolar epithelial cells. Our results indicate that the influenza virus specifically targets the PPARγ pathway in macrophages to cause acute injury to the lung.


Assuntos
Influenza Humana , Orthomyxoviridae , Animais , Síndrome da Liberação de Citocina , Humanos , Pulmão/metabolismo , Macrófagos/metabolismo , Camundongos , PPAR gama/metabolismo , Troglitazona
3.
PLoS One ; 17(9): e0272415, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36054097

RESUMO

Influenza viruses (Inf-V) are an important cause of acute respiratory infection (ARI) in children. This study was undertaken to describe the clinical and epidemiological characteristics of Inf-V infections in a sample of hospitalized children with ARI. Nasopharyngeal aspirates (NPA) from 500 children between 1 month to 5 years old with symptoms of ARI were collected at the Teaching Hospital Kegalle Sri Lanka From May 2016 to June 2018, NPAs were tested for influenza A (Inf-A) and B (Inf-B) viruses, human respiratory syncytial virus (hRSV), human parainfluenza virus (hPIV) 1-3 using an immunofluorescence assay. The Inf-V were then subtyped using a multiplex RT-PCR. Inf-V were detected in 10.75% (54/502) of the hospitalized children with ARI and in that 5.57% (28/502) were positive for Inf-A and 5.17% (26/502) were positive for Inf-B. Of the 54 Inf-V positive children, 33 were aged between 6 and 20 months. Of the 28 children infected with Inf-A, 15 had uncharacterized lower respiratory infection, 7 had bronchopneumonia and 6 had bronchiolitis. Of the 26 children infected with Inf-B, 11 had uncharacterized lower respiratory infection, 10 had bronchiolitis, and 4 had bronchopneumonia. Inf-B circulated throughout the year with a few peaks, one in June and then in August followed by November to December in 2016 and one in April 2017 and January 2018. Inf-A circulated throughout the year with a major peak in March to April 2017 and July 2018. ARI was more common in boys compared to girls. Majority of the children infected with Inf-V were diagnosed with uncharacterized lower respiratory infection and mild to moderate bronchiolitis. Inf-V infections were prevalent throughout the year in the study area of Sri Lanka with variations in the type of the circulating virus.


Assuntos
Broncopneumonia , Doenças Transmissíveis , Influenza Humana , Orthomyxoviridae , Infecções por Vírus Respiratório Sincicial , Infecções Respiratórias , Vírus , Criança , Criança Hospitalizada , Feminino , Humanos , Lactente , Influenza Humana/epidemiologia , Masculino , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções Respiratórias/epidemiologia , Sri Lanka/epidemiologia
4.
Virology ; 574: 37-46, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35914365

RESUMO

To improve cross-protection of influenza vaccination, we tested conjugation of conserved M2e epitopes to the surface of inactivated influenza virus (iPR8-M2e*). Treatment of virus with chemical cross-linker led to diminished hemagglutination activity and failure to induce hemagglutination inhibiting antibodies. Conjugated iPR8-M2e* vaccine was less protective against homologous and heterosubtypic viruses, despite the induction of virus-specific binding IgG antibodies. In alternative approaches to enhance cross-protection, we developed a genetically linked chimeric protein (M2e-B stalk) vaccine with M2e of influenza A and hemagglutinin (HA) stalk of influenza B virus. Vaccination of mice with inactivated influenza A virus supplemented with M2e-B stalk effectively induced hemagglutination inhibiting antibodies, humoral and cellular M2e immune responses, and enhanced heterosubtypic protection. This study demonstrates the importance of HA functional integrity in influenza vaccine efficacy and that supplementation of influenza vaccines with M2e-B stalk protein could be a feasible strategy of improving cross-protection against influenza viruses.


Assuntos
Vacinas contra Influenza , Influenza Humana , Infecções por Orthomyxoviridae , Orthomyxoviridae , Animais , Anticorpos Antivirais , Proteção Cruzada , Hemaglutinação , Humanos , Influenza Humana/prevenção & controle , Camundongos , Camundongos Endogâmicos BALB C
5.
Biosystems ; 220: 104740, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35934256

RESUMO

Influenza viruses mutate rapidly and can pose a threat to public health, especially to those in vulnerable groups. Throughout history, influenza A viruses have caused pandemics between different species. It is important to identify the origin of a virus in order to prevent the spread of an outbreak. Recently, there has been increasing interest in using machine learning algorithms to provide fast and accurate predictions for viral sequences. In this study, real testing data sets and a variety of evaluation metrics were used to evaluate machine learning algorithms at different taxonomic levels. As hemagglutinin is the major protein in the immune response, only hemagglutinin sequences were used and represented by position-specific scoring matrix and word embedding. The results suggest that the 5-grams-transformer neural network is the most effective algorithm for predicting viral sequence origins, with approximately 99.54% AUCPR, 98.01% F1 score and 96.60% MCC at a higher classification level, and approximately 94.74% AUCPR, 87.41% F1 score and 80.79% MCC at a lower classification level.


Assuntos
Vírus da Influenza A , Orthomyxoviridae , Algoritmos , Hemaglutininas/genética , Vírus da Influenza A/genética , Aprendizado de Máquina
6.
Proc Natl Acad Sci U S A ; 119(33): e2208011119, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35939703

RESUMO

The subunits of the influenza hemagglutinin (HA) trimer are synthesized as single-chain precursors (HA0s) that are proteolytically cleaved into the disulfide-linked polypeptides HA1 and HA2. Cleavage is required for activation of membrane fusion at low pH, which occurs at the beginning of infection following transfer of cell-surface-bound viruses into endosomes. Activation results in extensive changes in the conformation of cleaved HA. To establish the overall contribution of cleavage to the mechanism of HA-mediated membrane fusion, we used cryogenic electron microscopy (cryo-EM) to directly image HA0 at neutral and low pH. We found extensive pH-induced structural changes, some of which were similar to those described for intermediates in the refolding of cleaved HA at low pH. They involve a partial extension of the long central coiled coil formed by melting of the preexisting secondary structure, threading it between the membrane-distal domains, and subsequent refolding as extended helices. The fusion peptide, covalently linked at its N terminus, adopts an amphipathic helical conformation over part of its length and is repositioned and packed against a complementary surface groove of conserved residues. Furthermore, and in contrast to cleaved HA, the changes in HA0 structure at low pH are reversible on reincubation at neutral pH. We discuss the implications of covalently restricted HA0 refolding for the cleaved HA conformational changes that mediate membrane fusion and for the action of antiviral drug candidates and cross-reactive anti-HA antibodies that can block influenza infectivity.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza , Fusão de Membrana , Orthomyxoviridae , Internalização do Vírus , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Humanos , Concentração de Íons de Hidrogênio , Orthomyxoviridae/fisiologia , Conformação Proteica
7.
PLoS One ; 17(8): e0265288, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35921317

RESUMO

OBJECTIVES: Acute respiratory infections (ARIs) are one of the leading causes of childhood morbidity and mortality worldwide. However, there is limited surveillance data on the epidemiological burden of respiratory pathogens in tropical countries like Malaysia. This study aims to estimate the prevalence of respiratory pathogens causing ARIs among children aged <18 years old in Malaysia and their epidemiological characteristics. METHODS: Nasopharyngeal swab specimens received at 12 laboratories located in different states of Malaysia from 2015-2019 were studied. Detection of 18 respiratory pathogens were performed using multiplex PCR. RESULTS: Data from a total of 23,306 paediatric patients who presented with ARI over a five-year period was studied. Of these, 18538 (79.5%) were tested positive. The most prevalent respiratory pathogens detected in this study were enterovirus/ rhinovirus (6837/ 23000; 29.7%), influenza virus (5176/ 23000; 22.5%) and respiratory syncytial virus (RSV) (3652/ 23000; 15.9%). Throughout the study period, RSV demonstrated the most pronounce seasonality; peak infection occurred during July to September. Whereas the influenza virus was detected year-round in Malaysia. No seasonal variation was noted in other respiratory pathogens. The risk of RSV hospitalisation was found to be significantly higher in children aged less than two years old, whereas hospitalisation rates for the influenza virus peaked at children aged between 3-6 years old. CONCLUSION: This study provides insight into the epidemiology and the seasonality of the causative pathogens of ARI among the paediatric population in Malaysia. Knowledge of seasonal respiratory pathogens epidemiological dynamics will facilitate the identification of a target window for vaccination.


Assuntos
Orthomyxoviridae , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Vírus , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Malásia/epidemiologia , Prevalência , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções Respiratórias/epidemiologia , Estações do Ano
8.
Virus Res ; 320: 198898, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35995240

RESUMO

An active surveillance study of avian influenza viruses (AIVs) in wild birds was carried out in Kazakhstan in 2018-2019. In total, 866 samples were collected from wild birds and analyzed for influenza viruses using molecular and virological tests. Genome segments of Asian, European, and Australian lineages were detected in 25 (4.6%) out of 541 waterfowl samples positive for subtype H3N8, and in two (0.6%) out of 325 H3N8 positive samples from terrestrial birds. No highly pathogenic avian influenza virus (AIV) was detected. The results indicated transmission of closely related strains or identical subtypes of AIVs by a flock-unit of migratory birds or annual cyclical pattern of subtype dominance. The simultaneous circulation of genome segments of the Asian, European and Australian genetic lineages of H3N8 AIVs in wild birds in Kazakhstan indicated the important role of Central Asia as a transmission hub of AI viruses linking the East Asian migratory flyways with European flyways and vice versa.


Assuntos
Vírus da Influenza A Subtipo H3N8 , Vírus da Influenza A , Influenza Aviária , Orthomyxoviridae , Animais , Animais Selvagens , Austrália , Aves , Vírus da Influenza A Subtipo H3N8/genética , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Cazaquistão/epidemiologia , Filogenia
9.
PLoS Comput Biol ; 18(8): e1010394, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35984845

RESUMO

When two influenza viruses co-infect the same cell, they can exchange genome segments in a process known as reassortment. Reassortment is an important source of genetic diversity and is known to have been involved in the emergence of most pandemic influenza strains. However, because of the difficulty in identifying reassortment events from viral sequence data, little is known about their role in the evolution of the seasonal influenza viruses. Here we introduce TreeKnit, a method that infers ancestral reassortment graphs (ARG) from two segment trees. It is based on topological differences between trees, and proceeds in a greedy fashion by finding regions that are compatible in the two trees. Using simulated genealogies with reassortments, we show that TreeKnit performs well in a wide range of settings and that it is as accurate as a more principled bayesian method, while being orders of magnitude faster. Finally, we show that it is possible to use the inferred ARG to better resolve segment trees and to construct more informative visualizations of reassortments.


Assuntos
Influenza Humana , Orthomyxoviridae , Teorema de Bayes , Genoma Viral/genética , Humanos , Orthomyxoviridae/genética , Filogenia , Vírus Reordenados/genética
10.
Cell Rep Med ; 3(8): 100718, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35977467

RESUMO

The conserved hemagglutinin stalk domain is an attractive target for broadly effective antibody-based therapeutics and next-generation universal influenza vaccines. Protection provided by hemagglutinin stalk-binding antibodies is principally mediated through activation of immune effector cells. Titers of stalk-binding antibodies are highly variable on an individual level and tend to increase with age as a result of increasing exposures to influenza virus. In our study, we show that stalk-binding antibodies cooperate with neuraminidase inhibitors to protect against influenza virus infection in an Fc-dependent manner. These data suggest that the effectiveness of neuraminidase inhibitors is likely influenced by an individual's titers of stalk-binding antibodies and that neuraminidase inhibitors may enhance the effectiveness of future stalk-binding monoclonal antibody-based treatments.


Assuntos
Vacinas contra Influenza , Influenza Humana , Orthomyxoviridae , Anticorpos Antivirais , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Hemaglutininas , Humanos , Fragmentos Fc das Imunoglobulinas/imunologia , Influenza Humana/tratamento farmacológico , Neuraminidase
11.
Artigo em Inglês | MEDLINE | ID: mdl-36012090

RESUMO

Air purifiers should pay much attention to hospital-associated infections, but the role of a single air purifier is limited. The goal of this study was to evaluate the effectiveness of the combined application of the nonequilibrium positive and negative oxygen ion purifier (PNOI) and the high-efficiency particulate air filter (HEPA) on a complex, polluted environment. Two of the better performing purifiers were selected before the study. The efficacy of their use alone and in combination for purification of cigarette particulate matter (PM), Staphylococcus albicans, and influenza virus were then evaluated under a simulated contaminated ward. PNAI and HEPA alone are deficient. However, when they were combined, they achieved 98.44%, 99.75%, and 100% 30 min purification rates for cigarette PM, S. albus, and influenza virus, respectively. The purification of pollution of various particle sizes and positions was optimized and reduced differentials, and a subset of airborne influenza viruses is inactivated. Furthermore, they were superior to ultraviolet disinfection for microbial purification in air. This work demonstrates the strong purification capability of the combined application of these two air purifiers for complex air pollution, which provides a new idea for infection control in medical institutions.


Assuntos
Filtros de Ar , Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Orthomyxoviridae , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Bactérias , Poeira , Hospitais , Material Particulado/análise
12.
Viruses ; 14(8)2022 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-36016306

RESUMO

Influenza viruses are responsible for millions of cases globally and significantly threaten public health. Since pandemic and zoonotic influenza viruses have emerged in the last 20 years and some of the viruses have resulted in high mortality in humans, a universal influenza vaccine is needed to provide comprehensive protection against a wide range of influenza viruses. Current seasonal influenza vaccines provide strain-specific protection and are less effective against mismatched strains. The rapid antigenic drift and shift in influenza viruses resulted in time-consuming surveillance and uncertainty in the vaccine protection efficacy. Most recent universal influenza vaccine studies target the conserved antigen domains of the viral surface glycoproteins and internal proteins to provide broader protection. Following the development of advanced vaccine technologies, several innovative strategies and vaccine platforms are being explored to generate robust cross-protective immunity. This review provides the latest progress in the development of universal influenza vaccines.


Assuntos
Vacinas contra Influenza , Influenza Humana , Infecções por Orthomyxoviridae , Orthomyxoviridae , Anticorpos Antivirais , Humanos
13.
Front Immunol ; 13: 927593, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35967412

RESUMO

An appropriate level of reactive oxygen species (ROS) is necessary for cell proliferation, signaling transduction, and apoptosis due to their highly reactive character. ROS are generated through multiple metabolic pathways under a fine-tuned control between oxidant and antioxidant signaling. A growing number of evidence has proved their highly relevant role in modulating inflammation during influenza virus infection. As a network of biological process for protecting organism from invasion of pathogens, immune system can react and fight back through either innate immune system or adaptive immune system, or both. Herein, we provide a review about the mechanisms of ROS generation when encounter influenza virus infection, and how the imbalanced level of ROS influences the replication of virus. We also summarize the pathways used by both the innate and adaptive immune system to sense and attack the invaded virus and abnormal levels of ROS. We further review the limitation of current strategies and discuss the direction of future work.


Assuntos
Doenças Transmissíveis , Influenza Humana , Infecções por Orthomyxoviridae , Orthomyxoviridae , Humanos , Espécies Reativas de Oxigênio/metabolismo
14.
Math Biosci Eng ; 19(9): 9125-9146, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35942752

RESUMO

Influenza is a respiratory infection caused influenza virus. To evaluate the effect of environment noise on the transmission of influenza, our study focuses on a stochastic influenza virus model with disease resistance. We first prove the existence and uniqueness of the global solution to the model. Then we obtain the existence of a stationary distribution to the positive solutions by stochastic Lyapunov function method. Moreover, certain sufficient conditions are provided for the extinction of the influenza virus flu. Finally, several numerical simulations are revealed to illustrate our theoretical results. Conclusively, according to the results of numerical models, increasing disease resistance is favorable to disease control. Furthermore, a simple example demonstrates that white noise is favorable to the disease's extinction.


Assuntos
Influenza Humana , Orthomyxoviridae , Simulação por Computador , Resistência à Doença , Humanos , Influenza Humana/epidemiologia , Processos Estocásticos
15.
Curr Protoc ; 2(7): e465, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35848945

RESUMO

Influenza is an infectious respiratory disease with significant morbidity and mortality rates among people of all ages. Influenza viruses spread and evolve rapidly in the human population. Different immune histories, given by previous exposures to influenza virus infections and/or vaccinations, result in a great diversity of humoral and cellular immune responses. Understanding protective immune responses induced against circulating virus strains and potential pandemic strains is vital for infection prevention and disease mitigation. Vaccine formulations for seasonal influenza must be reformulated annually to stay abreast of occurring virus mutations. Assays to measure the capacity of antibodies to neutralize influenza viruses provide a good estimate of protection against future infections with strains similar or identical to those used in the assay. Here, we describe a detailed protocol of our standard in vitro microneutralization assay to assess the neutralization activity of polyclonal sera or purified monoclonal antibodies. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Microneutralization assay to assess virus inhibition by serum or monoclonal antibodies Support Protocol 1: Preparation of cDMEM Support Protocol 2: Preparation and aliquoting of TPCK-treated trypsin Support Protocol 3: Inactivation of serum samples by RDE treatment.


Assuntos
Vacinas contra Influenza , Influenza Humana , Orthomyxoviridae , Anticorpos Monoclonais , Anticorpos Antivirais , Humanos , Vacinas contra Influenza/genética , Neuraminidase/genética
16.
Int J Mol Sci ; 23(13)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35806369

RESUMO

Virus-cell fusion is the key step for viral infection in host cells. Studies on virus binding and fusion with host cells are important for understanding the virus-host interaction and viral pathogenesis for the discovery of antiviral drugs. In this review, we focus on the virus-cell fusions induced by the two major pandemic viruses, including the influenza virus and SARS-CoV-2. We further compare the cell fusions induced by the influenza virus and SARS-CoV-2, especially the pH-dependent fusion of the influenza virus and the fusion of SARS-CoV-2 in the type-II transmembrane serine protease 2 negative (TMPRSS2-) cells with syncytia formation. Finally, we present the development of drugs used against SARA-CoV-2 and the influenza virus through the discovery of anti-fusion drugs and the prevention of pandemic respiratory viruses.


Assuntos
COVID-19 , Orthomyxoviridae , Fusão Celular , Humanos , Orthomyxoviridae/metabolismo , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/metabolismo , Internalização do Vírus
17.
Sci Rep ; 12(1): 12757, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35882911

RESUMO

The Madin-Darby canine kidney (MDCK) cell line is an in vitro model for influenza A virus (IAV) infection and propagation. MDCK-SIAT1 (SIAT1) and humanized MDCK (hCK) cell lines are engineered MDCK cells that express N-glycans with elevated levels of sialic acid (Sia) in α2,6-linkage (α2,6-Sia) that are recognized by many human IAVs. To characterize the N-glycan structures in these cells and the potential changes compared to the parental MDCK cell line resulting from engineering, we analyzed the N-glycans from these cells at different passages, using both mass spectrometry and specific lectin and antibody binding. We observed significant differences between the three cell lines in overall complex N-glycans and terminal galactose modifications. MDCK cells express core fucosylated, bisected complex-type N-glycans at all passage stages, in addition to expressing α2,6-Sia on short N-glycans and α2,3-Sia on larger N-glycans. By contrast, SIAT1 cells predominantly express α2,6-Sia glycans and greatly reduced level of α2,3-Sia glycans. Additionally, they express bisected, sialylated N-glycans that are scant in MDCK cells. The hCK cells exclusively express α2,6-Sia glycans. Unexpectedly, hCK glycoproteins bound robustly to the plant lectin MAL-1, indicating α2,3-Sia glycans, but such binding was not Sia-dependent and closely mirrored that of an antibody that recognizes glycans with terminal 3-O-sulfate galactose (3-O-SGal). The 3-O-SGal epitope is highly expressed in N-glycans on multiple hCK glycoproteins. These results indicate vastly different N-glycomes between MDCK cells and the engineered clones that could relate to IAV infectivity.


Assuntos
Vírus da Influenza A , Influenza Humana , Orthomyxoviridae , Animais , Cães , Galactose/metabolismo , Glicoproteínas/metabolismo , Humanos , Vírus da Influenza A/metabolismo , Rim/metabolismo , Células Madin Darby de Rim Canino , Ácido N-Acetilneuramínico/metabolismo , Orthomyxoviridae/metabolismo , Polissacarídeos/metabolismo , Sulfatos/metabolismo
18.
Biomacromolecules ; 23(8): 3213-3221, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35797332

RESUMO

Biomimicry of the mucin barrier function is an efficient strategy to counteract influenza. We report the simple aminolyzation of poly(methyl vinyl ether-alt-maleic anhydride) (PM) using amine-terminated poly(ethylene glycol)ylated oleanolic acid (OAPEG) to mimic the mucin structure and its adsorption of the influenza virus. Direct interactions between influenza hemagglutinin (HA) and the prepared macromolecule evaluated by surface plasmon resonance and isothermal titration calorimetry demonstrated that the multivalent presentation of OAPEG on PM enhanced the binding affinity to HA with a decrease in KD of approximately three orders of magnitude compared with monomeric OAPEG. Moreover, hemagglutination inhibition assay, viral growth inhibition assay, and cytopathic effect reduction assay indicated that the nonglycosylated polymer could mimic natural heavily glycosylated mucin and thus promote the attachment of the virus in a subnanomolar range. Further investigation of the antiviral effects via time-of-addition assay, dynamic light scattering experiments, and transmission electron microscopy photographs indicated that the pseudomucin could adsorb the virion particles and synergistically inhibit the early attachment and final release steps of the influenza infection cycle. These findings demonstrate the effectiveness of the macromolecule in the physical sequestration and prevention of viral infection. Notably, due to its structural similarities with mucin, the biomacropolymer also has the potential for the rational design of antiviral drugs, influenza adsorbents, or filtration materials and the construction of model systems to explore protection against other pathogenic viruses.


Assuntos
Influenza Humana , Ácido Oleanólico , Orthomyxoviridae , Adsorção , Antivirais/química , Antivirais/farmacologia , Humanos , Influenza Humana/tratamento farmacológico , Mucinas , Ácido Oleanólico/química , Ácido Oleanólico/farmacologia , Ácido Oleanólico/uso terapêutico , Polietilenoglicóis/farmacologia , Polímeros/farmacologia
19.
Med Intensiva (Engl Ed) ; 46(8): 426-435, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35868719

RESUMO

OBJECTIVE: To determine the incidence and impact of Aspergillus spp. isolation (AI) on ICU mortality in critically ill patients with severe influenza pneumonia during the first 24h of admission. DESIGN: Secondary analysis of an observational and prospective cohort study. SETTING: ICUs voluntary participating in the Spanish severe Influenza pneumonia registry, between June 2009 and June 2019. PATIENTS: Consecutive patients admitted to the ICU with diagnosis of severe influenza pneumonia, confirmed by real-time polymerase chain reaction. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Incidence of AI in respiratory samples. Demographic variables, comorbidities, need for mechanical ventilation and the presence of shock according at admission. Acute Physiology and Chronic Health Evaluation II (APACHE II) scale calculated on ICU admission. RESULTS: 3702 patients were analyzed in this study. AI incidence was 1.13% (n=42). Hematological malignancies (OR 4.39, 95% CI 1.92-10.04); HIV (OR 3.83, 95% CI 1.08-13.63), and other immunosuppression situations (OR 4.87, 95% CI 1.99-11.87) were factors independently associated with the presence of Aspergillus spp. The automatic CHAID decision tree showed that hematologic disease with an incidence of 3.3% was the most closely AI related variable. Hematological disease (OR 2.62 95% CI 1.95-3.51), immunosuppression (OR 2.05 95% CI 1.46-2.88) and AI (OR 3.24, 95% CI 1.60-6.53) were variables independently associated with ICU mortality. CONCLUSIONS: Empirical antifungal treatment in our population may only be justified in immunocompromised patients. In moderate-high risk cases, active search for Aspergillus spp. should be implemented.


Assuntos
Influenza Humana , Orthomyxoviridae , Pneumonia , Aspergillus , Estado Terminal , Humanos , Influenza Humana/complicações , Influenza Humana/epidemiologia , Estudos Prospectivos
20.
Anal Bioanal Chem ; 414(22): 6419-6430, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35841415

RESUMO

Short-chain fatty acids (SCFAs) are the end products of the fermentation of complex carbohydrates by the gut microbiota. Although SCFAs are recognized as important markers to elucidate the link between gut health and disease, it has been difficult to analyze SCFAs with mass spectrometry technologies due to their poor ionization efficiency and high volatility. Here, we present a novel and sensitive method for the quantification of SCFAs, including C2-C6 SCFAs and their hydroxy derivatives, by liquid chromatography/tandem mass spectrometry (LC-MS/MS) upon N,N-dimethylethylenediamine (DMED) derivatization with a run time of 10 min. Moreover, the quantification method of DMED-derivatized SCFAs in intestinal contents using isotope-labeled internal standards was also established. The method validation was performed by analyzing spiked intestinal samples; the limits of detection and quantification of SCFAs with this method were found to be 0.5 and 5 fmol, respectively; the recovery was greater than 80% and good linearity (0.9932 to 0.9979) of calibration curves was obtained over the range from 0.005 to 5000 pmol/µL; the intraday and interday precisions were achieved in the range of 1-5%. Furthermore, the validated method was applied to analyze SCFAs in the cecum and colon contents of mice infected with the influenza virus. The results showed that the concentration of most of the SCFAs tested here decreased significantly in a time-dependent manner after the infection, suggesting a possibility that SCFAs in intestinal samples could be used as severe disease markers. Overall, we here successfully developed a simple, fast, and sensitive method for SCFA analysis by LC-MS/MS combined with DMED derivatization. The method for the quantification of SCFAs will be a useful tool for both basic research and clinical studies.


Assuntos
Influenza Humana , Orthomyxoviridae , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida/métodos , Etilenodiaminas , Ácidos Graxos Voláteis/análise , Humanos , Camundongos , Espectrometria de Massas em Tandem/métodos
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