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1.
Eur J Med Chem ; 186: 111861, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31734025

RESUMO

Respiratory syncytial virus (RSV) and influenza A virus (IAV) are two of the most common viruses that cause substantial morbidity and mortality in infants, young children, elderly persons, and immunocompromised individuals worldwide. Currently, there are no licensed vaccines or selective antiviral drugs against RSV infections and most IAV strains become resistant to clinical anti-influenza drug. Here, we described the discovery of a series of 2-((1H-indol-3-yl)thio)-N-phenyl-acetamide as novel and potent RSV and IAV dual inhibitors. Thirty-five derivatives were designed, prepared, and evaluated for their anti-RSV and anti-IAV activities. Among the tested compounds, 14'c, 14'e, 14'f, 14'h, and 14'i exhibited excellent activity against both RSV and IAV, which showed low micromolar to sub-micromolar EC50 values. Further, compounds 14'c and 14'e were identified as the most promising dual inhibitors with lesser cytotoxicity than the clinical drug, ribavirin. These findings may contribute to the development of a lead compound for the treatment of RSV and/or IAV infections.


Assuntos
Acetamidas/farmacologia , Antivirais/farmacologia , Desenho de Fármacos , Influenzavirus A/efeitos dos fármacos , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Acetamidas/síntese química , Acetamidas/química , Antivirais/síntese química , Antivirais/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
2.
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
3.
Nat Rev Microbiol ; 17(4): 233-245, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30723301

RESUMO

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract disease in young children and elderly people. Although the virus was isolated in 1955, an effective RSV vaccine has not been developed, and the only licensed intervention is passive immunoprophylaxis of high-risk infants with a humanized monoclonal antibody. During the past 5 years, however, there has been substantial progress in our understanding of the structure and function of the RSV glycoproteins and their interactions with host cell factors that mediate entry. This period has coincided with renewed interest in developing effective interventions, including the isolation of potent monoclonal antibodies and small molecules and the design of novel vaccine candidates. In this Review, we summarize the recent findings that have begun to elucidate RSV entry mechanisms, describe progress on the development of new interventions and conclude with a perspective on gaps in our knowledge that require further investigation.


Assuntos
Antivirais/farmacologia , Interações entre Hospedeiro e Microrganismos/efeitos dos fármacos , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Vírus Sincicial Respiratório Humano/fisiologia , Internalização do Vírus/efeitos dos fármacos , Anticorpos Monoclonais/farmacologia , Ensaios Clínicos como Assunto , Humanos , Infecções por Vírus Respiratório Sincicial/terapia , Bibliotecas de Moléculas Pequenas/farmacologia , Vacinas Virais
4.
PLoS One ; 14(2): e0212687, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30789963

RESUMO

Respiratory syncytial virus (RSV) is a common cause of respiratory tract infections in children and immunocompromised individuals. A multi-center surveillance of the epidemiologic and molecular characteristics of RSV circulating in Lebanon was performed. The attachment (G) and fusion (F) glycoproteins were analyzed and compared to those reported regionally and globally. 16% (83/519) of the nasopharyngeal swabs collected during the 2016/17 season tested positive for RSV; 50% (27/54) were RSV-A and 50% (27/54) were RSV-B. Phylogenetic analysis of the G glycoprotein revealed predominance of the RSVA ON1 genotype, in addition to two novel Lebanese genotype variants, hereby named LBA1 and LBA2, which descended from the ON1 and NA2 RSV-A genotypes, respectively. RSV-B strains belonged to BA9 genotype except for one BA10. Deduced amino acid sequences depicted several unique substitutions, alteration of glycosylation patterns and the emergence of palivizumab resistance among the Lebanese viruses. The emergence of ON1 and other novel genotypes that are resistant to palivizumab highlights the importance of monitoring RSV globally.


Assuntos
Antivirais/farmacologia , Farmacorresistência Viral , Palivizumab/farmacologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Adolescente , Adulto , Antivirais/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Líbano/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Mutação , Palivizumab/uso terapêutico , Filogenia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Adulto Jovem
5.
Eur J Pediatr ; 178(2): 131-138, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30610420

RESUMO

Respiratory syncytial virus (RSV) infection is one of the main causes of infant hospitalization and mortality. The single-stranded RNA virus codes for 11 proteins of which the F protein, a surface epitope responsible for RSV fusion, is the most targeted for developing antiviral medicines and vaccines. The peak of symptoms occurs around day 4 to 6 of illness and the airway obstruction is merely caused by the host immune inflammatory response. Risk factors for severe bronchiolitis are prematurity, comorbidity, and/or being immunocompromised. At present, there are no curative therapies available for RSV infections and treatment is supportive only. Development of new antiviral medicines is however promising. The aim of this review is to give a summary of the most important new antiviral therapies in clinical development for RSV infection and to explain their mode of action. We therefore performed a literature search on this topic.Conclusion: There are currently at least eight antivirals being investigated in clinical trials. They all use different approaches to either focus on preventing viral fusion with host cells or inhibiting virus replication. Some target RSV surface epitopes like the F protein to halt fusion, others aim for RNA chain termination, while small interfering RNAs downregulate viral protein production. What is known: • RSV bronchiolitis is a very important pediatric disease as it is one of the main causes of infant hospitalization and mortality. By the age of 2 years, 95% of all the infants worldwide will have been infected. • The only recommended therapy is supportive since there are no existing curative therapies yet. What this study adds: • This review gives an overview of the current progress in the research field of RSV antivirals with background information on their mode of action.


Assuntos
Antivirais/uso terapêutico , Bronquiolite Viral/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Bronquiolite Viral/virologia , Criança , Pré-Escolar , Humanos , Lactente
6.
J Med Chem ; 62(7): 3206-3227, 2019 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-30411898

RESUMO

Respiratory syncytial virus (RSV) is a globally prevalent viral infection with limited treatment options which hospitalizes millions each year. Treatment options have been limited to palivizumab, a monoclonal antibody, approved for prophylaxis in high-risk infants and ribavirin with very limited efficacy and significant safety concerns. This Perspective surveys the range of direct acting antiviral agents (DAAs) that target key steps in the viral life cycle. A number of approaches to DAAs have produced landmark clinical studies over the past few years, notably in fusion and nucleoside inhibitors, and an update of the clinical status of these compounds is provided. Non-nucleoside inhibitors of replication are reviewed in addition to inhibitors of other mechanisms, notably the RSV N and G proteins. This article will provide an informative perspective of the current status of drug discovery targeted at providing an effective therapy for RSV infection.


Assuntos
Antivirais/química , Descoberta de Drogas , Bibliotecas de Moléculas Pequenas/química , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Humanos , Proteínas do Nucleocapsídeo/química , Proteínas do Nucleocapsídeo/metabolismo , Palivizumab/imunologia , Palivizumab/uso terapêutico , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Vírus Sincicial Respiratório Humano/imunologia , Vírus Sincicial Respiratório Humano/metabolismo , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/uso terapêutico , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/metabolismo
7.
J Virol ; 93(4)2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30541831

RESUMO

Respiratory syncytial virus (RSV) is a leading cause of hospitalization of infants and young children, causing considerable respiratory disease and repeat infections that may lead to chronic respiratory conditions such as asthma, wheezing, and bronchitis. RSV causes ∼34 million new episodes of lower respiratory tract illness (LRTI) in children younger than 5 years of age, with >3 million hospitalizations due to severe RSV-associated LRTI. The standard of care is limited to symptomatic relief as there are no approved vaccines and few effective antiviral drugs; thus, a safe and efficacious RSV therapeutic is needed. Therapeutic targeting of host proteins hijacked by RSV to facilitate replication is a promising antiviral strategy as targeting the host reduces the likelihood of developing drug resistance. The nuclear export of the RSV M protein, mediated by the nuclear export protein exportin 1 (XPO1), is crucial for RSV assembly and budding. Inhibition of RSV M protein export by leptomycin B correlated with reduced RSV replication in vitro In this study, we evaluated the anti-RSV efficacy of Verdinexor (KPT-335), a small molecule designed to reversibly inhibit XPO1-mediated nuclear export. KPT-335 inhibited XPO1-mediated transport and reduced RSV replication in vitro KPT-335 was effective against RSV A and B strains and reduced viral replication following prophylactic or therapeutic administration. Inhibition of RSV replication by KPT-335 was due to a combined effect of reduced XPO1 expression, disruption of the nuclear export of RSV M protein, and inactivation of the NF-κB signaling pathway.IMPORTANCE RSV is an important cause of LRTI in infants and young children for which there are no suitable antiviral drugs offered. We evaluated the efficacy of KPT-335 as an anti-RSV drug and show that KPT-335 inhibits XPO1-mediated nuclear export, leading to nuclear accumulation of RSV M protein and reduction in RSV levels. KPT-335 treatment also resulted in inhibition of proinflammatory pathways, which has important implications for its effectiveness in vivo.


Assuntos
Acrilamidas/farmacologia , Hidrazinas/farmacologia , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Células A549 , Acrilamidas/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Antivirais/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Glicoproteínas/imunologia , Humanos , Hidrazinas/metabolismo , Carioferinas/efeitos dos fármacos , Carioferinas/metabolismo , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/metabolismo , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Células Vero
8.
Vaccine ; 36(52): 8069-8078, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30389195

RESUMO

Human respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infections in newborns, young children, elderly, and immune-compromised. The RSV fusion (F) glycoprotein is a major focus of vaccine development and the target of palivizumab (Synagis®) which is licensed as an immuno-prophylactic for use in newborn children at high risk of infection. However, clinical use of a narrowly targeted monoclonal antibodies leads to the generation of escape mutant strains that are fully resistant to neutralization by the antibody. Herein, we evaluated the RSV F nanoparticle vaccine (RSV F vaccine), produced as near-full-length, pre-fusogenic F trimers that form stable protein-detergent nanoparticles. The RSV F vaccine induces polyclonal antibodies that bind to antigenic site II as well as other epitopes known to be broadly neutralizing. Cotton rats immunized with the RSV F vaccine produced antibodies that were both neutralizing and protected against wild-type RSV infection, as well as against a palivizumab-resistant mutant virus. Use of aluminum phosphate adjuvant with the RSV F vaccine increased site II antibody avidity 100 to 1000-fold, which correlated with enhanced protection against challenge. The breadth of the vaccine-induced antibody response was demonstrated using competitive binding with monoclonal antibodies targeting antigenic sites Ø, II, IV, and VIII found on pre-fusion and post-fusion conformations of RSV F. In summary, we found the RSV F vaccine induced antibodies that bind to conserved epitopes including those defined as pre-fusion F specific; that use of adjuvant increased antibody avidity that correlated with enhanced protection in the cotton rat challenge model; and the polyclonal, high-avidity antibodies neutralized and protected against both wild-type and palivizumab-resistant mutant virus. These data support the ongoing clinical development of the aluminum phosphate adjuvanted RSV F nanoparticle vaccine.


Assuntos
Palivizumab/farmacologia , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Proteínas Virais de Fusão/imunologia , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alumínio/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Afinidade de Anticorpos , Antivirais/farmacologia , Farmacorresistência Viral , Epitopos/imunologia , Feminino , Masculino , Mutação , Nanopartículas/administração & dosagem , Fosfatos/imunologia , Ratos , Vírus Sincicial Respiratório Humano/genética , Sigmodontinae , Vacinação
9.
J Med Chem ; 61(22): 10228-10241, 2018 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-30339388

RESUMO

A novel benzoazepinequnoline (BAQ) series was discovered as RSV fusion inhibitors. BAQ series originated from compound 2, a hit from similarity-based virtual screening. In SAR exploration, benzoazepine allowed modifications in the head moiety. Benzylic sulfonyl on benzoazepine and 6-Me on quinoline were crucial for good anti-RSV activity. Although the basic amine in the head portion was crucial for anti-RSV activity, the attenuated basicity was required to reduce Vss. Introducing oxetane to the head portion led to discovery of compound 1, which demonstrated single-digit nM anti-RSV activity against different RSV strains, reasonable oral exposure in plasma, and 78-fold higher exposure in lung. Compound 1 also displayed 1 log viral reduction in a female BALB/c mice RSV model by b.i.d. oral dosing at 12.5 mg/kg. A single resistant mutant at L138F in fusion protein proved compound 1 to be a RSV fusion inhibitor.


Assuntos
Antivirais/química , Antivirais/farmacologia , Quinolinas/química , Quinolinas/farmacologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Administração Oral , Animais , Antivirais/administração & dosagem , Antivirais/farmacocinética , Disponibilidade Biológica , Feminino , Células Hep G2 , Humanos , Camundongos , Quinolinas/administração & dosagem , Quinolinas/farmacocinética , Relação Estrutura-Atividade
10.
J Biol Chem ; 293(43): 16761-16777, 2018 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-30206124

RESUMO

Respiratory syncytial virus (RSV) represents a significant health threat to infants and to elderly or immunocompromised individuals. There are currently no vaccines available to prevent RSV infections, and disease management is largely limited to supportive care, making the identification and development of effective antiviral therapeutics against RSV a priority. To identify effective chemical scaffolds for managing RSV disease, we conducted a high-throughput anti-RSV screen of a 57,000-compound library. We identified a hit compound that specifically blocked activity of the RSV RNA-dependent RNA polymerase (RdRp) complex, initially with moderate low-micromolar potency. Mechanistic characterization in an in vitro RSV RdRp assay indicated that representatives of this compound class block elongation of RSV RNA products after initial extension by up to three nucleotides. Synthetic hit-to-lead exploration yielded an informative 3D quantitative structure-activity relationship (3D-QSAR) model and resulted in analogs with more than 20-fold improved potency and selectivity indices (SIs) of >1,000. However, first-generation leads exhibited limited water solubility and poor metabolic stability. A second optimization strategy informed by the 3D-QSAR model combined with in silico pharmacokinetics (PK) predictions yielded an advanced lead, AVG-233, that demonstrated nanomolar activity against both laboratory-adapted RSV strains and clinical RSV isolates. This anti-RSV activity extended to infection of established cell lines and primary human airway cells. PK profiling in mice revealed 34% oral bioavailability of AVG-233 and sustained high drug levels in the circulation after a single oral dose of 20 mg/kg. This promising first-in-class lead warrants further development as an anti-RSV drug.


Assuntos
Antivirais/farmacologia , RNA Replicase/metabolismo , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Transcrição Genética/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Regulação Alostérica , Animais , Células Cultivadas , Humanos , Masculino , Camundongos , RNA Replicase/genética , Infecções por Vírus Respiratório Sincicial/metabolismo , Infecções por Vírus Respiratório Sincicial/virologia , Proteínas Virais/metabolismo
11.
Diagn Microbiol Infect Dis ; 92(3): 206-209, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30177420
12.
Virology ; 523: 129-139, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30144786

RESUMO

Experimental results in vitro and in animal models are used to guide researchers in testing vaccines or treatment in humans. However, viral kinetics are different in vitro, in animals, and in humans, so it is sometimes difficult to translate results from one system to another. In this study, we use a mathematical model to fit experimental data from multiple cycle respiratory syncytial virus (RSV) infections in vitro, in african green monkey (AGM), and in humans in order to quantitatively compare viral kinetics in the different systems. We find that there are differences in viral clearance rate, productively infectious cell lifespan, and eclipse phase duration between in vitro and in vivo systems and among different in vivo systems. We show that these differences in viral kinetics lead to different estimates of drug effectiveness of fusion inhibitors in vitro and in AGM than in humans.


Assuntos
Modelos Estatísticos , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Inibidores de Proteínas Virais de Fusão/uso terapêutico , Proteínas Virais de Fusão/antagonistas & inibidores , Internalização do Vírus/efeitos dos fármacos , Adulto , Idoso , Animais , Criança , Expressão Gênica , Especificidade de Hospedeiro , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/virologia , Fusão de Membrana/efeitos dos fármacos , Infecções por Vírus Respiratório Sincicial/patologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Vírus Sincicial Respiratório Humano/crescimento & desenvolvimento , Vírus Sincicial Respiratório Humano/metabolismo , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/metabolismo , Carga Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
13.
Fitoterapia ; 130: 118-124, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30165177

RESUMO

Two new oleanane-type triterpenoids (1-2), a new ursane-type triterpenoid (3), and a new podocarpane-type diterpenoid (4), together with 20 known compounds (5-24) were isolated from the stems of Celastrus hindsii Benth. Their structures were identified on the basis of the spectral data (HRESIMS, IR, UV, 1D, and 2D NMR) and the absolute configurations were determined by comparison of experimental and calculated ECD data. The structures of 1 and 4 were further confirmed by single crystal X-ray diffraction analysis. In addition, all compounds were evaluated for their in vitro antiviral activities against respiratory syncytium virus (RSV) using cytopathic effect (CPE) reduction assay. Compounds 7, 10, 11, 19 and 24 exhibited obvious anti-RSV activity with IC50 values from 1.55 to 6.25 µM.


Assuntos
Antivirais/farmacologia , Celastrus/química , Ácido Oleanólico/farmacologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Antivirais/isolamento & purificação , China , Estrutura Molecular , Ácido Oleanólico/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Caules de Planta/química
14.
Am J Respir Cell Mol Biol ; 59(6): 733-744, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30095982

RESUMO

Respiratory syncytial virus (RSV) is a leading cause of mortality in infants and young children. Despite the RSV disease burden, no vaccine is available, and treatment remains nonspecific. New drug candidates are needed to combat RSV. Toward this goal, we screened over 2,000 compounds to identify approved drugs with novel anti-RSV activity. Cardiac glycosides, inhibitors of the membrane-bound Na+/K+-ATPase, were identified to have anti-RSV activity. Cardiac glycosides diminished RSV infection in human epithelial type 2 cells and in primary human airway epithelial cells grown at an air-liquid interface. Digoxin, a U.S. Food and Drug Administration-approved cardiac glycoside, was also able to inhibit infection of primary nasal epithelial cells with community isolates of RSV. Our results suggest that the antiviral effects of cardiac glycosides may be dependent on changes in the intracellular Na+ and K+ composition. Consistent with this mechanism, we demonstrated that the ionophoric antibiotics salinomycin, valinomycin, and monensin inhibited RSV in human epithelial type 2 cells and primary nasal epithelial cells. Our data indicate that the K+/Na+-sensitive steps in the RSV life cycle occur within the initial 4 hours of viral infection but do not include virus binding/entry. Rather, our findings demonstrated a negative effect on the RSV transcription and/or replication process. Overall, this work suggests that targeting intracellular ion concentrations offers a novel antiviral strategy.


Assuntos
Glicosídeos Cardíacos/farmacologia , Células Epiteliais/efeitos dos fármacos , Mucosa Nasal/efeitos dos fármacos , Potássio/metabolismo , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Sódio/metabolismo , Antivirais/farmacologia , Células Cultivadas , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Homeostase , Humanos , Mucosa Nasal/metabolismo , Mucosa Nasal/virologia , Infecções por Vírus Respiratório Sincicial/metabolismo , Infecções por Vírus Respiratório Sincicial/virologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores
15.
Viruses ; 10(8)2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30110893

RESUMO

Prevention of severe lower respiratory tract infections in infants caused by the human respiratory syncytial virus (hRSV) remains a major public health priority. Currently, the major focus of vaccine development relies on the RSV fusion (F) protein since it is the main target protein for neutralizing antibodies induced by natural infection. The protein conserves 5 N-glycosylation sites, two of which are located in the F2 subunit (N27 and N70), one in the F1 subunit (N500) and two in the p27 peptide (N116 and N126). To study the influence of the loss of one or more N-glycosylation sites on RSV F immunogenicity, BALB/c mice were immunized with plasmids encoding RSV F glycomutants. In comparison with F WT DNA immunized mice, higher neutralizing titres were observed following immunization with F N116Q. Moreover, RSV A2-K-line19F challenge of mice that had been immunized with mutant F N116Q DNA was associated with lower RSV RNA levels compared with those in challenged WT F DNA immunized animals. Since p27 is assumed to be post-translationally released after cleavage and thus not present on the mature RSV F protein, it remains to be elucidated how deletion of this glycan can contribute to enhanced antibody responses and protection upon challenge. These findings provide new insights to improve the immunogenicity of RSV F in potential vaccine candidates.


Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vacinas de DNA/administração & dosagem , Proteínas Virais de Fusão/genética , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Feminino , Glicosilação , Humanos , Hidrólise , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Mutação , Plasmídeos/administração & dosagem , Plasmídeos/genética , Plasmídeos/imunologia , Engenharia de Proteínas , Subunidades Proteicas/administração & dosagem , Subunidades Proteicas/genética , Subunidades Proteicas/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/virologia , Vacinas contra Vírus Sincicial Respiratório/genética , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Vírus Sincicial Respiratório Humano/genética , Vírus Sincicial Respiratório Humano/imunologia , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Proteínas Virais de Fusão/administração & dosagem , Proteínas Virais de Fusão/imunologia , Carga Viral/efeitos dos fármacos
16.
Biomed Pharmacother ; 103: 1376-1383, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29864921

RESUMO

Human respiratory syncytial virus (RSV) is a common virus that causes pneumonia and bronchitis, mostly in infants. Our previous study showed that Jinxin oral liquid (JOL), derived from traditional Chinese medicine, had anti-inflammatory and therapeutic effects on RSV-related pneumonia. However, little is known about the underlying mechanisms of these effects. During a viral infection, including RSV infection, the inflammasome pathway is excessively activated, resulting in an inflammatory reaction and severe tissue damage. Inhibition of the inflammasome pathway has shown good therapeutic effects on lung inflammation. In the present study, we explored the effect of JOL on RSV-induced excessive inflammation in BALB/c mice. Pathological evaluation of lung tissue and measurement of the lung index showed that JOL alleviated lung infection and tissue injury induced by RSV. The enzyme-linked immunosorbent assay showed that JOL reduced the release of inflammatory factors, including interleukin-1ß(IL-1ß), interleukin-18(IL-18) and interleukin-33(IL-33), in the serum and lung homogenate of RSV-infected mice. Furthermore, the results of real-time PCR, immunohistochemistry, and western blot analyses showed that JOL inhibited the immune inflammatory response of mice infected with RSV through blockade of the NOD-like receptor protein 3(NLRP3)/apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC)/Caspase-1 signalling pathway, as evidenced by the down regulation of the mRNA and protein expression of three key components in the pathway. Collectively, our results showed that JOL inhibited pulmonary inflammation caused by RSV infection. Thus, JOL may be a promising remedy for lung inflammation caused by RSV infection and may help avoid lung tissue damage.


Assuntos
Caspase 1/metabolismo , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/farmacologia , Inflamação/metabolismo , Inflamação/virologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Transdução de Sinais , Administração Oral , Animais , Citocinas/sangue , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/uso terapêutico , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Camundongos Endogâmicos BALB C , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Infecções por Vírus Respiratório Sincicial/sangue , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/patologia , Infecções por Vírus Respiratório Sincicial/virologia , Transdução de Sinais/efeitos dos fármacos
17.
Respir Res ; 19(1): 123, 2018 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-29929556

RESUMO

The Human Viral Challenge (HVC) model has, for many decades, helped in the understanding of respiratory viruses and their role in disease pathogenesis. In a controlled setting using small numbers of volunteers removed from community exposure to other infections, this experimental model enables proof of concept work to be undertaken on novel therapeutics, including vaccines, immunomodulators and antivirals, as well as new diagnostics.Crucially, unlike conventional phase 1 studies, challenge studies include evaluable efficacy endpoints that then guide decisions on how to optimise subsequent field studies, as recommended by the FDA and thus licensing studies that follow. Such a strategy optimises the benefit of the studies and identifies possible threats early on, minimising the risk to subsequent volunteers but also maximising the benefit of scarce resources available to the research group investing in the research. Inspired by the principles of the 3Rs (Replacement, Reduction and Refinement) now commonly applied in the preclinical phase, HVC studies allow refinement and reduction of the subsequent development phase, accelerating progress towards further statistically powered phase 2b studies. The breadth of data generated from challenge studies allows for exploration of a wide range of variables and endpoints that can then be taken through to pivotal phase 3 studies.We describe the disease burden for acute respiratory viral infections for which current conventional development strategies have failed to produce therapeutics that meet clinical need. The Authors describe the HVC model's utility in increasing scientific understanding and in progressing promising therapeutics through development.The contribution of the model to the elucidation of the virus-host interaction, both regarding viral pathogenicity and the body's immunological response is discussed, along with its utility to assist in the development of novel diagnostics.Future applications of the model are also explored.


Assuntos
Antivirais/uso terapêutico , Infecções Respiratórias/tratamento farmacológico , Vacinas Virais/uso terapêutico , Antivirais/farmacologia , Ensaios Clínicos como Assunto/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/fisiopatologia , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/fisiopatologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Vírus Sincicial Respiratório Humano/fisiologia , Infecções Respiratórias/fisiopatologia , Rhinovirus/efeitos dos fármacos , Rhinovirus/fisiologia , Carga Viral/efeitos dos fármacos , Carga Viral/fisiologia , Vacinas Virais/farmacologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-29891600

RESUMO

Morbidity and mortality resulting from influenza-like disease are a threat, especially for older adults. To improve case management, next-generation broad-spectrum antiviral therapeutics that are efficacious against major drivers of influenza-like disease, including influenza viruses and respiratory syncytial virus (RSV), are urgently needed. Using a dual-pathogen high-throughput screening protocol for influenza A virus (IAV) and RSV inhibitors, we have identified N4-hydroxycytidine (NHC) as a potent inhibitor of RSV, influenza B viruses, and IAVs of human, avian, and swine origins. Biochemical in vitro polymerase assays and viral RNA sequencing revealed that the ribonucleotide analog is incorporated into nascent viral RNAs in place of cytidine, increasing the frequency of viral mutagenesis. Viral passaging in cell culture in the presence of an inhibitor did not induce robust resistance. Pharmacokinetic profiling demonstrated dose-dependent oral bioavailability of 36 to 56%, sustained levels of the active 5'-triphosphate anabolite in primary human airway cells and mouse lung tissue, and good tolerability after extended dosing at 800 mg/kg of body weight/day. The compound was orally efficacious against RSV and both seasonal and highly pathogenic avian IAVs in mouse models, reducing lung virus loads and alleviating disease biomarkers. Oral dosing reduced IAV burdens in a guinea pig transmission model and suppressed virus spread to uninfected contact animals through direct transmission. Based on its broad-spectrum efficacy and pharmacokinetic properties, NHC is a promising candidate for future clinical development as a treatment option for influenza-like diseases.


Assuntos
Antivirais/farmacologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Animais , Células Cultivadas , Cobaias , Humanos , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/genética , Vírus da Influenza B/efeitos dos fármacos , Vírus da Influenza B/genética , Camundongos , RNA Viral/genética , Vírus Sincicial Respiratório Humano/genética , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Vírus Sinciciais Respiratórios/genética
19.
MAbs ; 10(5): 778-795, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29733750

RESUMO

Respiratory syncytial virus (RSV) is a common cause of acute lower respiratory disease in infants and young children worldwide. Currently, treatment is supportive and no vaccines are available. The use of newborn lambs to model hRSV infection in human infants may provide a valuable tool to assess safety and efficacy of new antiviral drugs and vaccines. ALX-0171 is a trivalent Nanobody targeting the hRSV fusion (F) protein and its therapeutic potential was evaluated in newborn lambs infected with a human strain of RSV followed by daily ALX-0171 nebulization for 3 or 5 consecutive days. Colostrum-deprived newborn lambs were infected with hRSV-M37 before being treated by daily nebulization with either ALX-0171 or placebo. Two different treatment regimens were examined: day 1-5 or day 3-5 post-infection. Lambs were monitored daily for general well-being and clinical parameters. Respiratory tissues and bronchoalveolar lavage fluid were collected at day 6 post-inoculation for the quantification of viral lesions, lung viral titers, viral antigen and lung histopathology. Administration by inhalation of ALX-0171 was well-tolerated in these hRSV-infected newborn lambs. Robust antiviral effects and positive effects on hRSV-induced lung lesions and reduction in symptoms of illness were noted. These effects were still apparent when treatment start was delayed and coincided with peak viral loads (day 3 post-infection) and at a time point when signs of RSV disease were apparent. The latter design is expected to have high translational value for planned clinical trials. These results are indicative of the therapeutic potential of ALX-0171 in infants.


Assuntos
Modelos Animais de Doenças , Infecções por Vírus Respiratório Sincicial/veterinária , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Doenças dos Ovinos/prevenção & controle , Anticorpos de Domínio Único/administração & dosagem , Administração por Inalação , Animais , Animais Recém-Nascidos , Antivirais/administração & dosagem , Líquido da Lavagem Broncoalveolar/virologia , Humanos , Lactente , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/virologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/fisiologia , Ovinos , Doenças dos Ovinos/virologia , Carga Viral/efeitos dos fármacos
20.
Viruses ; 10(5)2018 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-29747463

RESUMO

We have recently shown that endogenous hydrogen sulfide (H2S), an important cellular gaseous mediator, exerts an antiviral and anti-inflammatory activity in vitro and in vivo, and that exogenous H2S delivered via the synthetic H2S-releasing compound GYY4137 also has similar properties. In this study, we sought to extend our findings to a novel class of H2S donors, thiol-activated gem-dithiol-based (TAGDDs). In an in vitro model of human respiratory syncytial virus (RSV) infection, TAGDD-1 treatment significantly reduced viral replication, even when added up to six hours after infection. Using a mouse model of RSV infection, intranasal delivery of TAGDD-1 to infected mice significantly reduced viral replication and lung inflammation, markedly improving clinical disease parameters and pulmonary dysfunction, compared to vehicle treated controls. Overall our results indicate that this novel synthetic class of H2S-releasing compounds exerts antiviral and anti-inflammatory activity in the context of RSV infection and represents a potential novel pharmacological approach to ameliorate viral-induced lung disease.


Assuntos
Antivirais/farmacologia , Sulfeto de Hidrogênio/farmacologia , Morfolinas/farmacologia , Compostos Organotiofosforados/farmacologia , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Células A549 , Administração Intranasal , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Vírus Respiratório Sincicial/metabolismo , Vírus Sincicial Respiratório Humano/fisiologia , Compostos de Sulfidrila/química
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