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1.
Eur J Pharmacol ; 882: 173328, 2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32603692

RESUMO

The novel coronavirus, later identified as SARS-CoV-2, originating from Wuhan in China in November 2019, quickly spread around the world becoming a pandemic. Despite the knowledge of previous coronaviruses, such as those responsible for the SARS and MERS-CoV epidemic, there is no drug or prophylaxis treatment to this day. The rapid succession of scientific findings on SARS-CoV-2 provides a significant number of potential drug targets. Nevertheless, at the same time, the high quantity of clinical data, generated by a large number of rapidly infected people, require accurate tests regarding effective medical treatments. Several in vitro and in vivo studies were rapidly initiated after the outbreak of the pandemic COVID-19. Initial clinical studies revealed the promising potential of remdesivir that demonstrated a powerful and specific in vitro antiviral activity for COVID-19. Promising effects appear to be attributable to hydroxychloroquine. Remdesivir and hydroxychloroquine are being tested in ongoing randomized trials. In contrast, oseltamivir was not effective and corticosteroids are not currently recommended. However, few data from ongoing clinical trials are identifying low molecular weight heparins, innate immune system stimulating agents, and inflammatory modulating agents as potential effective agents. The authors assume that the current pandemic will determine the need for a systematic approach based on big data analysis for identifying effective drugs to defeat SARS-Cov-2. This work is aimed to be a general reference point and to provide an overview as comprehensive as possible regarding the main clinical trials in progress at the moment.


Assuntos
Adjuvantes Imunológicos/farmacologia , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Mediadores da Inflamação/farmacologia , Pneumonia Viral/tratamento farmacológico , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Monofosfato de Adenosina/uso terapêutico , Adjuvantes Imunológicos/uso terapêutico , Alanina/análogos & derivados , Alanina/farmacologia , Alanina/uso terapêutico , Antivirais/uso terapêutico , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Ensaios Clínicos como Assunto , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Glucocorticoides/farmacologia , Glucocorticoides/uso terapêutico , Heparina de Baixo Peso Molecular/farmacologia , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Hidroxicloroquina/farmacologia , Hidroxicloroquina/uso terapêutico , Imunidade Inata/efeitos dos fármacos , Mediadores da Inflamação/uso terapêutico , Oseltamivir/farmacologia , Oseltamivir/uso terapêutico , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Resultado do Tratamento
2.
PLoS Pathog ; 16(6): e1008592, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32555740

RESUMO

The neuraminidase (NA) inhibitor (NAI) oseltamivir (OST) is the most widely used influenza antiviral drug. Several NA amino acid substitutions are reported to reduce viral susceptibility to OST in in vitro assays. However, whether there is a correlation between the level of reduction in susceptibility in vitro and the efficacy of OST against these viruses in vivo is not well understood. In this study, a ferret model was utilised to evaluate OST efficacy against circulating influenza A and B viruses with a range of in vitro generated 50% inhibitory concentrations (IC50) values for OST. OST efficacy against an A(H1N1)pdm09 and an A(H1N1)pdm09 virus with the H275Y substitution in neuraminidase was also tested in the macaque model. The results from this study showed that OST had a significant impact on virological parameters compared to placebo treatment of ferrets infected with wild-type influenza A viruses with normal IC50 values (~1 nM). However, this efficacy was lower against wild-type influenza B and other viruses with higher IC50 values. Differing pathogenicity of the viruses made evaluation of clinical parameters difficult, although some effect of OST in reducing clinical signs was observed with influenza A(H1N1) and A(H1N1)pdm09 (H275Y) viruses. Viral titres in macaques were too low to draw conclusive results. Analysis of the ferret data revealed a correlation between IC50 and OST efficacy in reducing viral shedding but highlighted that the current WHO guidelines/criteria for defining normal, reduced or highly reduced inhibition in influenza B viruses based on in vitro data are not well aligned with the low in vivo OST efficacy observed for both wild-type influenza B viruses and those with reduced OST susceptibility.


Assuntos
Vírus da Influenza A Subtipo H1N1/metabolismo , Vírus da Influenza A Subtipo H3N2/metabolismo , Vírus da Influenza B/metabolismo , Infecções por Orthomyxoviridae , Oseltamivir/farmacologia , Substituição de Aminoácidos , Animais , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Furões , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza B/genética , Macaca fascicularis , Macrolídeos , Masculino , Mutação de Sentido Incorreto , Neuraminidase/genética , Neuraminidase/metabolismo , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/patologia
3.
Nat Commun ; 11(1): 2750, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32487990

RESUMO

Influenza viruses annually kill 290,000-650,000 people worldwide. Antivirals can reduce death tolls. Baloxavir, the recently approved influenza antiviral, inhibits initiation of viral mRNA synthesis, whereas oseltamivir, an older drug, inhibits release of virus progeny. Baloxavir blocks virus replication more rapidly and completely than oseltamivir, reducing the duration of infectiousness. Hence, early baloxavir treatment may indirectly prevent transmission. Here, we estimate impacts of ramping up and accelerating baloxavir treatment on population-level incidence using a new model that links viral load dynamics from clinical trial data to between-host transmission. We estimate that ~22 million infections and >6,000 deaths would have been averted in the 2017-2018 epidemic season by administering baloxavir to 30% of infected cases within 48 h after symptom onset. Treatment within 24 h would almost double the impact. Consequently, scaling up early baloxavir treatment would substantially reduce influenza morbidity and mortality every year. The development of antivirals against the SARS-CoV2 virus that function like baloxavir might similarly curtail transmission and save lives.


Assuntos
Antivirais/uso terapêutico , Epidemias , Influenza Humana/tratamento farmacológico , Orthomyxoviridae/efeitos dos fármacos , Oxazinas/uso terapêutico , Piridinas/uso terapêutico , Tiepinas/uso terapêutico , Triazinas/uso terapêutico , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Proliferação de Células , Infecções por Coronavirus/tratamento farmacológico , Humanos , Influenza Humana/virologia , Oseltamivir/farmacologia , Oseltamivir/uso terapêutico , Oxazinas/farmacologia , Pandemias , Pneumonia Viral/tratamento farmacológico , Saúde Pública , Piridinas/farmacologia , RNA Mensageiro/metabolismo , Estações do Ano , Tiepinas/farmacologia , Triazinas/farmacologia , Carga Viral , Replicação Viral/efeitos dos fármacos
4.
J Infect Chemother ; 26(8): 775-779, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32249161

RESUMO

To assess the extent of susceptibility to the four most commonly used neuraminidase inhibitors (NAIs) of the epidemic viruses in the 2018-19 Japanese influenza season, we measured the 50% inhibitory concentration (IC50) of four NAIs, oseltamivir, zanamivir, peramivir, and laninamivir, for influenza virus isolates from patients and compared them with the results from the 2010-11 to 2017-18 seasons. Viral isolation was done with specimens obtained prior to and after treatment, and the type/subtype was determined by RT-PCR using type- and subtype-specific primers. The IC50 was determined by a neuraminidase inhibition assay using a fluorescent substrate. Virus isolates, 51 A(H1N1)pdm09, 125 A(H3N2), and one B, were measured in the 2018-19 season and the geometric mean IC50s of the four NAIs were quite comparable to the previous eight studied seasons. No A(H1N1)pdm09 with highly reduced sensitivity for oseltamivir was found in the 2018-19 season prior to drug administration, although such A(H1N1)pdm09 were found in two, two, and two samples in the 2010-11, 2013-14, and 2015-16 seasons, respectively. No isolates with highly reduced sensitivity to the four NAIs were found for A(H3N2) or B through the 2010-11 to 2018-19 seasons. Among 18 samples with A(H1N1)pdm09 virus isolated after NAI administration, highly reduced sensitivity to oseltamivir and peramivir was detected from one of the five patients treated with oseltamivir. These results suggest that the sensitivity to the four commonly used NAIs has been maintained, although viruses with highly reduced sensitivity to oseltamivir and peramivir have emerged in some adult patients treated with oseltamivir.


Assuntos
Antivirais/farmacologia , Inibidores Enzimáticos/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza B/efeitos dos fármacos , Influenza Humana/virologia , Neuraminidase/antagonistas & inibidores , Adolescente , Adulto , Criança , Ciclopentanos/farmacologia , Farmacorresistência Viral , Feminino , Guanidinas/farmacologia , Humanos , Influenza Humana/tratamento farmacológico , Concentração Inibidora 50 , Japão , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Oseltamivir/farmacologia , Estações do Ano , Adulto Jovem , Zanamivir/análogos & derivados , Zanamivir/farmacologia
5.
PLoS One ; 15(3): e0229601, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130243

RESUMO

A community outbreak of human influenza A(H1N1)pdm09 virus strains was observed in Myanmar in 2017. We investigated the circulation patterns, antigenicity, and drug resistance of 2017 influenza A(H1N1)pdm09 viruses from Myanmar and characterized the full genome of influenza virus strains in Myanmar from in-patients and out-patients to assess the pathogenicity of the viruses. Nasopharyngeal swabs were collected from out-patients and in-patients with acute respiratory tract infections in Yangon and Pyinmana City in Myanmar during January-December 2017. A total of 215 out-patients and 18 in-patients infected with A(H1N1)pdm09 were detected by virus isolation and real-time RT-PCR. Among the positive patients, 90.6% were less than 14 years old. Hemagglutination inhibition (HI) antibody titers against A(H1N1)pdm09 viruses in Myanmar were similar to the recommended Japanese influenza vaccine strain for 2017-2018 seasons (A/Singapore/GP1908/2015) and WHO recommended 2017 southern hemisphere vaccine component (A/Michigan/45/2015). Phylogenetic analysis of the hemagglutinin sequence showed that the Myanmar strains belonged to the genetic subclade 6B.1, possessing mutations of S162N and S164T at potential antigenic sites. However, the amino acid mutation at position 222, which may enhance the severity of disease and mortality, was not found. One case with no prior history of oseltamivir treatment possessed H275Y mutated virus in neuraminidase (NA), which confers resistance to oseltamivir and peramivir with elevated IC50 values. The full genome sequence of Myanmar strains showed no difference between samples from in-patients and out-patients, suggesting no additional viral mutations associated with patient severity. Several amino acid changes were observed in PB2, PB1, and M2 of Myanmar strains when compared to the vaccine strain and other Asian strains. However, no mutations associated with pathogenicity were found in the Myanmar strains, suggesting that viral factors cannot explain the underlying reasons of the massive outbreak in Myanmar. This study reported the first detection of an oseltamivir-resistant influenza virus in Myanmar, highlighting the importance of continuous antiviral monitoring and genetic characterization of the influenza virus in Myanmar.


Assuntos
Epidemias , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Adolescente , Adulto , Substituição de Aminoácidos , Antígenos Virais , Antivirais/farmacologia , Criança , Pré-Escolar , Farmacorresistência Viral/genética , Feminino , Genoma Viral , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Lactente , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Mianmar/epidemiologia , Oseltamivir/farmacologia , Filogenia , Adulto Jovem
6.
J Med Chem ; 63(6): 3120-3130, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32069052

RESUMO

Vaccination is the most prevalent prophylactic means for controlling seasonal influenza infections. However, an effective vaccine usually takes at least 6 months to develop for the circulating strains. Therefore, new therapeutic options are needed for the acute treatment of influenza infections to control this virus and prevent epidemics/pandemics from developing. We have discovered fast-acting, orally bioavailable acylated 4-aminopiperidines with an effective mechanism of action targeting viral hemagglutinin (HA). Our data show that these compounds are potent entry inhibitors of influenza A viruses. We present docking studies that suggest an HA binding site for these inhibitors on H5N1. Compound 16 displayed a significant decrease of viral titer when evaluated in the infectious assays with influenza virus H1N1 (A/Puerto Rico/8/1934) or H5N1 (A/Vietnam/1203/2004) strains and the oseltamivir-resistant strain with the most common H274Y mutation. In addition, compound 16 showed significant synergistic activity with oseltamivir in vitro.


Assuntos
Antivirais/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Oseltamivir/farmacologia , Piperidinas/farmacologia , Internalização do Vírus/efeitos dos fármacos , Animais , Antivirais/síntese química , Antivirais/metabolismo , Sítios de Ligação , Cães , Sinergismo Farmacológico , Hemaglutininas Virais/química , Hemaglutininas Virais/metabolismo , Humanos , Vírus da Influenza A Subtipo H1N1/química , Virus da Influenza A Subtipo H5N1/química , Células Madin Darby de Rim Canino , Camundongos , Testes de Sensibilidade Microbiana , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Piperidinas/síntese química , Piperidinas/metabolismo , Ligação Proteica , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade
7.
Biomed Pharmacother ; 121: 109471, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31707346

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: In recent years, Gegen Qinlian decoction (GQD) has been applied to treat influenza virus infection, and its clinical effectiveness has been shown. However, the potential mechanism by which GQD acts on influenza A virus (IAV) has not been fully elucidated. Traditional Chinese medicine (TCM) formulas are well known to have multiple targets and effects. Our previous experiments examined the mechanism by which TCM can be used to treat influenza from the perspective of the influenza immune mechanism. AIM OF THE STUDY: To explore the possible mechanism by which GQD affects mice infected with the FM1 strain of influenza virus. MATERIALS AND METHODS: Forty-eight C57BL/6 mice were divided randomly into four groups: a normal control (NG) group, an IAV infection (VG) group, an IAV + oseltamivir (30.44 mg/kg) treatment (VO) group, and an IAV + GQD (9.74 g/kg) treatment (VQ) group. We also grouped forty-eight Toll-like receptor 7 knockout (TLR7-/-) mice in the same manner. The pulmonary mRNA expression of TLR7, myeloid differentiation factor 88 (MyD88), and nuclear factor (NF)-κB p65 was measured by RT-qPCR, and the pulmonary protein expression of TLR7, MyD88, and NF-κB p65 was measured by western blot. The proportions of T helper (Th) 1, Th2, Th17 and regulatory T (Treg) cells were measured by flow cytometry. RESULTS: IAV infection led to low body weights and high viral load. Compared with those in the NG group, the mRNA expression levels of TLR7, MyD88, and NF-κB p65 in the VG group were upregulated (P < 0.05). However, the mRNA and protein expression levels of TLR7, MyD88, and NF-κB p65 were lower in the VO and VQ groups than in the VG group (P < 0.05). IAV infection led to increased proportions of Th1/Th2 and Th17/Treg cells in the VG group. In the VO and VQ groups, both Th2 and Th1 cell numbers were increased, resulting in a lower Th1/Th2 proportion than that in the VG group. CONCLUSIONS: GQD downregulated the expression of some key TLR signalling pathway factors. GQD also affected the differentiation of CD4+ T cells, thereby exerting a protective systemic effect on influenza virus infection. In conclusion, GQD activated a balanced inflammatory response in the host to limit immune pathological injury and improve clinical and survival outcomes.


Assuntos
Antivirais/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , Infecções por Orthomyxoviridae/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Receptor 7 Toll-Like/metabolismo , Animais , Regulação para Baixo/efeitos dos fármacos , Feminino , Masculino , Medicina Tradicional Chinesa/métodos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Infecções por Orthomyxoviridae/virologia , Oseltamivir/farmacologia , Linfócitos T/efeitos dos fármacos
8.
Biomed Pharmacother ; 121: 109652, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31734578

RESUMO

BACKGROUND: The aim of the present study was to investigate the synergistic effects and interactive mechanisms of Shufeng Jiedu Capsule (SFJDC) combined with oseltamivir in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) induced by the influenza A virus (IAV). METHODS: The extraction of SFJDC was analyzed by UHPLC/ESI Q-Orbitrap Mass Spectrometry. Human bronchial epithelial cells were isolated from COPD (DHBE) bronchial tissues, co-cultured with IAV for 24 h, and were subsequently treated with SFJDC and/or oseltamivir. Cell viability was detected by MTT assay. A rat model of COPD with IAV infection was established and treated with SFJDC and/or oseltamivir. Interleukin (IL)-1ß and IL-18 in serum and bronchoalveolar lavage fluid (BALF) were measured by ELISA. Additionally, mRNA and protein levels of NLRP3 inflammasome pathway were measured by quantitative real-time PCR and Western blotting, respectively. RESULTS: SFJDC and/or oseltamivir, at their optimal concentrations, had no significant cytotoxicity against DHBEs. The levels of NLRP3-inflammasome-associated components were significantly elevated after cells were inoculated with IAV, whereas the mRNA and protein levels of these components were significantly decreased after treatment with SFJDC and/or oseltamivir in vitro. Moreover, in vivo, the combination of SFJDC and oseltamivir improved survival rates, attenuated clinical symptoms, induced weight gain, alleviated lung damage, and significantly reduced IL-1ß and IL-18 levels in serum and BALF, as well as reduced the expression levels of NLRP3-associated components and viral titers in lung homogenates. CONCLUSION: SFJDC combined with oseltamivir treatment significantly attenuated IAV-induced airway inflammation and lung viral titers. Hence, our findings may provide a novel therapeutic strategy for IAV-induced respiratory infection.


Assuntos
Antivirais/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Oseltamivir/farmacologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/virologia , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/virologia , Animais , Brônquios/efeitos dos fármacos , Brônquios/metabolismo , Brônquios/virologia , Líquido da Lavagem Broncoalveolar/virologia , Linhagem Celular , Técnicas de Cocultura/métodos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/virologia , Influenza Humana/metabolismo , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/virologia , Masculino , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/virologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Carga Viral/efeitos dos fármacos
9.
Eur J Med Chem ; 185: 111841, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31708183

RESUMO

Influenza A neuraminidase plays an indispensable role in the process of replication and transmission of influenza, so the neuraminidase inhibition can prevent the reproduction of the viruses therefore achieve the effect of treatment of influenza. However, drug resistance of neuraminidase inhibitors such as oseltamivir highlights the need to develop novel structural neuraminidase inhibitors. Here we explored a series of oseltamivir derivatives bearing pyridyl group. Among them, compound 23b exhibiting potent inhibitory activity against neuraminidase from H5N1 subtype was comparable to oseltamivir carboxylate. Cytopathic effect inhibition assay in MDCK cells indicated that compound 23b exerted powerful inhibitions on influenza viruses. And compound 23b were nontoxic to MDCK cells. Meanwhile, compound 23b showed high stability towards rat liver microsomes, human liver microsomes and human plasma. This research enriched the structural type of neuraminidase inhibitors.


Assuntos
Antivirais/farmacologia , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Neuraminidase/antagonistas & inibidores , Oseltamivir/farmacologia , Animais , Antivirais/síntese química , Antivirais/química , Cães , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Virus da Influenza A Subtipo H5N1/enzimologia , Células Madin Darby de Rim Canino/efeitos dos fármacos , Células Madin Darby de Rim Canino/microbiologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Neuraminidase/metabolismo , Oseltamivir/síntese química , Oseltamivir/química , Relação Estrutura-Atividade
10.
Virol J ; 16(1): 149, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31783761

RESUMO

BACKGROUND: Vaccination and the use of neuraminidase inhibitors (NAIs) are currently the front lines of defense against seasonal influenza. The activity of influenza vaccines and antivirals drugs such as the NAIs can be affected by mutations in the influenza hemagglutinin (HA) protein. Numerous HA substitutions have been identified in nonclinical NAI resistance-selection experiments as well as in clinical specimens from NAI treatment or surveillance studies. These mutations are listed in the prescribing information (package inserts) for FDA-approved NAIs, including oseltamivir, zanamivir, and peramivir. METHODS: NAI treatment-emergent H1 HA mutations were mapped onto the H1N1 HA1 trimeric crystal structure and most of them localized to the HA antigenic sites predicted to be important for anti-influenza immunity. Recombinant A/California/04/09 (H1N1)-like viruses carrying HA V152I, G155E, S162 N, S183P, and D222G mutations were generated. We then evaluated the impact of these mutations on the immune reactivity and replication potential of the recombinant viruses in a human respiratory epithelial cell line, Calu- 3. RESULTS: We found that the G155E and D222G mutations significantly increased viral titers ~ 13-fold compared to the wild-type virus. The hemagglutination and microneutralization activity of goat and ferret antisera, monoclonal antibodies, and human serum samples raised against pandemic A(H1N1)pdm09 viruses was ~ 100-fold lower against mutants carrying G155E or D222G compared to the wild-type virus. CONCLUSIONS: Although the mechanism by which HA mutations emerge during NAI treatment is uncertain, some NAI treatment-emergent HA mutations correlate with decreased immunity to influenza virus.


Assuntos
Farmacorresistência Viral , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Proteínas Mutantes/genética , Proteínas Mutantes/imunologia , Mutação de Sentido Incorreto , Antivirais/farmacologia , Linhagem Celular , Cristalografia por Raios X , Ciclopentanos/farmacologia , Células Epiteliais/virologia , Epitopos/genética , Guanidinas/farmacologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/imunologia , Proteínas Mutantes/química , Neuraminidase/antagonistas & inibidores , Oseltamivir/farmacologia , Conformação Proteica , Seleção Genética , Proteínas Virais/antagonistas & inibidores , Replicação Viral , Zanamivir/farmacologia
11.
Acta Virol ; 63(3): 309-315, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507197

RESUMO

Influenza virus is activated by proteolytic cleavage of hemagglutinin by trypsin. After determining the optimal trypsin concentration, intracellular and extracellular influenza A/PR/8/34 (H1N1) and A/Victoria/361/2011 (H3N2) virus productions were compared in cultures treated with T-705 (favipiravir) and GS 4071 (an active form of oseltamivir). Although both drugs efficiently inhibited extracellular viral RNA release in a dose-dependent manner, T-705 inhibited it to the level of the inoculum without trypsin treatment, while GS 4071 inhibited it to a final level 10 times higher than that without trypsin. T-705 inhibited intracellular viral RNA production to the level of input virus in both trypsin-treated and untreated cells. In contrast, GS 4071 dose-dependently inhibited intracellular viral RNA production in cells treated with trypsin but allowed viral RNA synthesis. The level of maximum inhibition by GS 4071was 10 times higher than that of cells without trypsin and 1,000 times greater than the inoculum titer in cells without trypsin. T-705 inhibited both intracellular and extracellular virus production 1,000 and 10 times more strongly, respectively, than GS 4071. T-705 has powerful anti-influenza activity in the absence of trypsin and even in the trypsin-optimized growth condition, suggesting the therapeutic advantage in treatment of influenza complicated with bacterial pneumonia. Keywords: influenza; T-705; Tamiflu; trypsin; bacterial trypsin-like protease.


Assuntos
Amidas , Antivirais , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A Subtipo H3N2 , Pirazinas , Tripsina , Amidas/farmacologia , Antivirais/farmacologia , Linhagem Celular , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Oseltamivir/farmacologia , Pirazinas/farmacologia , RNA Viral/biossíntese , Tripsina/farmacologia
12.
Chin J Nat Med ; 17(9): 650-662, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31526500

RESUMO

Ge Gen Decoction (GGD), a Traditional Chinese Medicine prescription, is mainly used to treat infectious respiratory diseases and can relieve the symptoms of influenza A virus (IAV) infection. However, the underlying mechanism of GGD against IAV infection remains unclear. In this study, we found that GGD had moderate anti-IAV activity in vitro. GGD was more effective when given before the viral infection and targeted the viral attachment and replication stages rather than the internalization stage. In vivo, GGD treatment reduced thevirus titers of lung tissue significantly and improved the survival rate, lung index, and pulmonary histopathological changes in H1N1-infected mice. We observed the changes in several key immuno-related indexes in GGD administrated H1N1-infected mice with anti-IAV drug oseltamivir phosphate as the control. GGD treatment decreased the expression of TNF-α and improved Th1/Th2 immune balance to reduce the excessive immune response in H1N1-infected mice. Besides, the expression of the toll-like receptor 7 signaling pathway in H1N1-infected mice decreased after GGD treatment. Our results showed that GGD has anti-IAV activity and can modulate the immune system to relieve lung inflammation.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Vírus da Influenza A/efeitos dos fármacos , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/imunologia , Animais , Antivirais/administração & dosagem , Antivirais/química , Antivirais/farmacologia , Antivirais/uso terapêutico , Citocinas/metabolismo , Cães , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/química , Feminino , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A/fisiologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Células Madin Darby de Rim Canino , Glicoproteínas de Membrana/metabolismo , Camundongos Endogâmicos ICR , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Oseltamivir/administração & dosagem , Oseltamivir/farmacologia , Oseltamivir/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Equilíbrio Th1-Th2/efeitos dos fármacos , Receptor 7 Toll-Like/metabolismo , Ligação Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
13.
Eur J Med Chem ; 182: 111635, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31493744

RESUMO

The discovery of novel potent neuraminidase (NA) inhibitors remains an attractive approach for treating infectious diseases caused by influenza. In this study, we describe the design and synthesis of novel N-substituted oseltamivir derivatives for probing the 150-cavity which is nascent to the activity site of NA. NA inhibitory studies showed that new derivatives demonstrated the inhibitory activity with IC50 values at nM level against NA of a clinical influenza virus strain. Moreover, the in silico ADME predictions showed that the selected compounds had comparable properties with oseltamivir carboxylate, which demonstrated the druggablity of these derivatives. Furthermore, molecular docking studies showed that the most potent compound 6f and 10i could adopt different modes of binding interaction with NA, which may provide novel solutions for treating oseltamivir-resistant influenza. Based on the research results, we consider that compounds 6f and 10i have the potential for further studies as novel antiviral agents.


Assuntos
Antivirais/farmacologia , Inibidores Enzimáticos/farmacologia , Simulação de Acoplamento Molecular , Neuraminidase/antagonistas & inibidores , Orthomyxoviridae/efeitos dos fármacos , Oseltamivir/farmacologia , Antivirais/síntese química , Antivirais/química , Simulação por Computador , Relação Dose-Resposta a Droga , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Neuraminidase/metabolismo , Orthomyxoviridae/enzimologia , Oseltamivir/síntese química , Oseltamivir/química , Relação Estrutura-Atividade
14.
Emerg Microbes Infect ; 8(1): 1428-1437, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31560252

RESUMO

Switching of receptor binding preference has been widely considered as one of the necessary mutations for avian influenza viruses, enabling efficient transmissions between human hosts. By stably overexpressing B4GalNT2 gene in MDCK cells, surface α2,3-siallylactose receptors were modified without affecting α2,6-receptor expression. The cell line MDCK-B4GalNT2 was used as a tool to screen for α2,3-receptor requirements in a panel of influenza viruses with previously characterized glycan array data. Infection of viruses with α2,3-receptor binding capability was inhibited in MDCK-B4GalNT2 cells, with the exception of A/WSN/33 (WSN). Infection with the 2009 pandemic H1N1 strains, A/California/04/2009 (Cal04) and A/Hong Kong/415742/2009 (HK09), despite showing α2,6-receptor binding, was also found to be inhibited. Further investigation showed that viral inhibition was due to a reduction in viral entry rate and viral attachment. Recombinant WSN virus with the neuraminidase (NA) gene swapped to A/Puerto Rico/8/1934 (PR8) and Cal04 resulted in a significant viral inhibition in MDCK-B4GalNT2 cells. With oseltamivir, the NA active site was found to be important for the replication results of WSN, but not Cal04.


Assuntos
Vírus da Influenza A Subtipo H1N1/fisiologia , N-Acetilgalactosaminiltransferases/genética , Ácido N-Acetilneuramínico/metabolismo , Neuraminidase/metabolismo , Ligação Viral , Internalização do Vírus , Animais , Antivirais/farmacologia , Linhagem Celular , Cães , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/genética , Células Madin Darby de Rim Canino , N-Acetilgalactosaminiltransferases/metabolismo , Neuraminidase/genética , Oseltamivir/farmacologia , Replicação Viral/efeitos dos fármacos
15.
Indian J Med Microbiol ; 37(1): 42-49, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31424009

RESUMO

Introduction: Influenza A(H1N1)pdm09 virus, since its identification in April 2009, has continued to cause significant outbreaks of respiratory tract infections including pandemics in humans. In the course of its evolution, the virus has acquired many mutations with an ability to cause increased disease severity. A regular molecular surveillance of the virus is essential to mark the evolutionary changes that may cause a shift to the viral behavior. Materials and Methods: Samples of Throat/Nasal swabs were collected from a total of 3715 influenza-like illness cases and screened by Real-time Reverse Transcription-Polymerase Chain Reaction for influenza viruses. Nucleotide sequence analysis was done to identify changes in antigenicity of the virus strains. Results: The present study describes the molecular characteristics of influenza A(H1N1)pdm09 viruses detected in Assam of Northeast India during 2009-2015. Influenza A viruses were detected in 11.4% (425/3715), of which influenza A(H1N1)pdm09 viruses were detected in 41.4% (176/425). The nucleotide sequencing of influenza A(H1N1)pdm09 viruses revealed a total of 17 and 22 amino acid substitutions in haemagglutinin (HA) and neuraminidase (NA) genes of the virus, respectively, compared to contemporary vaccine strain A/California/07/2009. The important mutations detected in HA genes of A/Assam(H1N1)pdm09 strains included E391K, K180Q and S202T. Mutation 'N248D' which has an ability to develop oseltamivir resistance was also detected in NA gene of A/Assam(H1N1)pdm09 strains. Conclusions: Regular molecular surveillance of influenza A(H1N1)pdm09 is important to monitor the viral behavior in terms of increase virulence, drug resistance pattern and emergence of novel strains.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/epidemiologia , Neuraminidase/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antivirais/farmacologia , Sequência de Bases , Criança , Pré-Escolar , Feminino , Variação Genética/genética , Humanos , Índia/epidemiologia , Lactente , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Oseltamivir/farmacologia , Filogenia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA , Adulto Jovem
16.
Virology ; 536: 58-67, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31400550

RESUMO

Human infection with H7N9 virus has provoked global public health concern due to the substantial morbidity and mortality. Neuraminidase inhibitors (NAIs) are used as first-line drugs to treat the infection. However, virus quasispecies can evolve rapidly under drug pressure, which may alter various biological characteristics of virus. Using an in vitro evolution platform and next-generation sequencing, we found the presence of peramivir led to changes to the dominant populations of the virus. Two important amino acid substitutions were identified in NA, I222T and H274Y, which caused reduced susceptibilities to oseltamivir or both oseltamivir and peramivir as confirmed by enzyme- and cell-based assays. The NA-H274Y variant showed decreased replicative fitness at the early stage of infection accompanied with impaired NA function. The quasispecies evolution of H7N9 virus and the potential emergence of these two variants should be closely monitored, which may guide the adjustment of antiviral strategies.


Assuntos
Antivirais/farmacologia , Ciclopentanos/farmacologia , Farmacorresistência Viral/genética , Guanidinas/farmacologia , Subtipo H7N9 do Vírus da Influenza A/efeitos dos fármacos , Neuraminidase/genética , Proteínas Virais/genética , Substituição de Aminoácidos , Animais , Cães , Evolução Molecular , Expressão Gênica , Humanos , Subtipo H7N9 do Vírus da Influenza A/enzimologia , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/crescimento & desenvolvimento , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Neuraminidase/metabolismo , Oseltamivir/farmacologia , Carga Viral/efeitos dos fármacos , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacos
17.
Phytomedicine ; 64: 152904, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454654

RESUMO

BACKGROUND: Millions of people are infected by the influenza virus worldwide every year. Current selections of anti-influenza agents are limited and their effectiveness and drug resistance are still of concern. PURPOSE: Investigation on in vitro and in vivo effect of aloin from Aloe vera leaves against influenza virus infection. METHODS: In vitro antiviral property of aloin was measured by plaque reduction assay in which MDCK cells were infected with oseltamivir-sensitive A(H1N1)pdm09, oseltamivir-resistant A(H1N1)pdm09, H1N1 or H3N2 influenza A or with influenza B viruses in the presence of aloin. In vivo activity was tested in H1N1 influenza virus infected mice. Aloin-mediated inhibition of influenza neuraminidase activity was tested by MUNANA assay. Aloin treatment-mediated modulation of anti-influenza immunity was tested by the study of hemagglutinin-specific T cells in vivo. RESULTS: Aloin significantly reduced in vitro infection by all the tested strains of influenza viruses, including oseltamivir-resistant A(H1N1)pdm09 influenza viruses, with an average IC50 value 91.83 ± 18.97 µM. In H1N1 influenza virus infected mice, aloin treatment (intraperitoneal, once daily for 5 days) reduced virus load in the lungs and attenuated body weight loss and mortality. Adjuvant aloin treatment also improved the outcome with delayed oseltamivir treatment. Aloin inhibited viral neuraminidase and impeded neuraminidase-mediated TGF-ß activation. Viral neuraminidase mediated immune suppression with TGF-ß was constrained and influenza hemagglutinin-specific T cell immunity was increased. There was more infiltration of hemagglutinin-specific CD4+ and CD8+ T cells in the lungs and their production of effector cytokines IFN-γ and TNF-α was boosted. CONCLUSION: Aloin from Aloe vera leaves is a potent anti-influenza compound that inhibits viral neuraminidase activity, even of the oseltamivir-resistant influenza virus. With suppression of this virus machinery, aloin boosts host immunity with augmented hemagglutinin-specific T cell response to the infection. In addition, in the context of compromised benefit with delayed oseltamivir treatment, adjuvant aloin treatment ameliorates the disease and improves survival. Taken together, aloin has the potential to be further evaluated for clinical applications in human influenza.


Assuntos
Aloe/química , Antivirais/farmacologia , Emodina/análogos & derivados , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza B/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Neuraminidase/antagonistas & inibidores , Animais , Linhagem Celular , Farmacorresistência Viral , Emodina/farmacologia , Hemaglutininas/imunologia , Humanos , Vírus da Influenza A Subtipo H1N1/enzimologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/enzimologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza B/enzimologia , Vírus da Influenza B/imunologia , Influenza Humana/imunologia , Influenza Humana/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Oseltamivir/farmacologia , Folhas de Planta/química , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Proteínas Virais/antagonistas & inibidores
18.
Artif Cells Nanomed Biotechnol ; 47(1): 3485-3491, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31422717

RESUMO

Enterovirus 71 (EV71) which commonly caused the hand-foot-mouth disease (HFMD) has become one of public health challenges worldwide. However, no effective vaccines or drugs for this disease has been developed. Thus, there is an urgent need to find a new strategy for treating the EV71 infection. Oseltamivir (OT) is an effective antiviral agent, but continuous use of oseltamivir leads to a diminished therapeutic effect in the clinic. In order to improve the antiviral activity of oseltamivir, oseltamivir was loaded onto surfaces of selenium nanoparticles (SeNPs) to fabricate a functionalized antiviral nanoparticles SeNPs@OT. The size of SeNPs@OT was tested by TEM and dynamic light scattering. The chemical structure and elemental composition of SeNPs@OT were analyzed by FT-IR and EDX, respectively. SeNPs@OT exhibited good stability and effective drug release in serum and PBS. SeNPs@OT efficiently entered into human astrocyte U251 cells (host cells) via clathrin-associated endocytosis and inhibited EV71 proliferation, which could protect EV71-infected U251 cells from apoptosis through mitochondrial pathway. Furthermore, SeNPs@OT inhibited EV71 activity probably by reducing the generation of reactive oxygen species in EV71-infected U251 cells. Interestingly, SeNPs obviously enhanced antiviral activity of oseltamivir in the anti-EV71 cell model. Taken together, SeNPs@OT is a promising antiviral drug candidate for EV71 infection.


Assuntos
Astrocitoma/patologia , Enterovirus Humano A/efeitos dos fármacos , Nanopartículas/química , Oseltamivir/química , Oseltamivir/farmacologia , Selênio/química , Antivirais/efeitos adversos , Antivirais/química , Antivirais/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Humanos , Oseltamivir/efeitos adversos , Espécies Reativas de Oxigênio/metabolismo
19.
Vet Microbiol ; 235: 21-24, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282375

RESUMO

Occurrence of avian influenza (AI) with Neuraminidase (NA) mutations which confer reduced neuraminidase inhibitor (NAI) susceptibility has remained a cause of concern. The susceptibility to NAIs of 67 highly pathogenic avian influenza H5N1 viruses isolated during 2006-2012 in India was tested in phenotypic fluorescence-based NA inhibition assay, sequence analysis and in ovo. One isolate showed a novel NA I117T amino acid substitution (N2 numbering) and eight isolates showed previously known NAI-resistance marker mutations (I117V, E119D, N294S, total 9/67). The overall incidence of resistant variants was 13.4%. The novel I117T substitution reduced oseltamivir susceptibility by 18.6-fold and zanamivir susceptibility by 11.8-fold, compared to the wild type AI H5N1virus, thus showed cross-resistance to both oseltamivir and zanamivir in NA inhibition assays. However, the other two isolates with I117V substitution were sensitive to both the NAIs. In addition, the comparison of growth of the I117T and I117V variants in presence of NAI's in the in ovo assays exhibited difference in growth levels. The present study reports the natural occurrence of a novel I117T mutation in AI H5N1 virus conferring cross-resistance to oseltamivir and zanamivir highlighting the urgent need of antiviral surveillance of AI viruses.


Assuntos
Antivirais/farmacologia , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Neuraminidase/genética , Oseltamivir/farmacologia , Proteínas Virais/genética , Zanamivir/farmacologia , Substituição de Aminoácidos , Animais , Galinhas , Farmacorresistência Viral , Índia , Virus da Influenza A Subtipo H5N1/genética , Concentração Inibidora 50 , Mutação de Sentido Incorreto , Zigoto
20.
Virol J ; 16(1): 87, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266524

RESUMO

BACKGROUND: Human infection with avian influenza H7N9 virus was first reported in 2013. Since the fifth epidemic, a highly pathogenic avian influenza (HPAI) H7N9 virus has emerged and caused 33 human infections. Several potential NAI resistance sites have been found in human cases. However, the drug susceptibility and replication ability of HPAI H7N9 virus with such substitutions have not yet been studied. METHODS: Thirty-three HPAI H7N9 virus strains were isolated from human cases in China, and then sequences were analyzed to identify potential NAI resistance sites. Recombinant influenza viruses were generated to evaluate the effect of NA amino acid substitutions on NAI (oseltamivir or zanamivir) susceptibility and viral replication efficiency in MDCK cells. RESULTS: Four potential NAI resistance sites, R292 K, E119V, A246T or H274Y, were screened. All four substitutions conferred either reduced or highly reduced susceptibility to oseltamivir or zanamivir. 292 K not only highly reduced the susceptibility of HPAI H7N9 to oseltamivir but also induced an increase in the IC50 of zanamivir. 119 V or 274Y conferred reduced susceptibility of HPAI H7N9 to oseltamivir. Additionally, 246 T conferred reduced susceptibility to zanamivir. All tested NAI-resistant viruses were capable of replication in MDCK cells. The virus yields of rg006-NA292K were lower than those of rg006-NA292R at 24, 48, 72 and 96 h postinfection (P<0.05). Rg006-NA119V, rg006-NA246T or rg006-NA274Y showed comparable replication capacity to wild-type virus (except for rg006-NA274Y at 96 h, P<0.05). CONCLUSIONS: All 4 amino acid substitutions (R292 K, E119V, A246T or H274Y) in NA reduced the susceptibility of HPAI H7N9 to NAIs. The NAI-resistant mutations in HPAI H7N9, in most cases, did not reduce the replication ability of the virus in mammalian cells. Special attention needs to be paid to these mutations, and the development of new anti-H7N9 drugs is of great importance.


Assuntos
Antivirais/farmacologia , Inibidores Enzimáticos/farmacologia , Subtipo H7N9 do Vírus da Influenza A/efeitos dos fármacos , Subtipo H7N9 do Vírus da Influenza A/genética , Influenza Humana/virologia , Replicação Viral/efeitos dos fármacos , Substituição de Aminoácidos , Animais , Galinhas , Cães , Farmacorresistência Viral/genética , Humanos , Subtipo H7N9 do Vírus da Influenza A/fisiologia , Influenza Aviária , Células Madin Darby de Rim Canino , Neuraminidase/antagonistas & inibidores , Oseltamivir/farmacologia , Zanamivir/farmacologia
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