Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.314
Filtrar
1.
Int J Nanomedicine ; 15: 2071-2083, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32273703

RESUMO

Background and Purpose: Adjuvant can reduce vaccine dosage and acquire better immune protection to the body, which helps to deal with the frequent outbreaks of influenza. Nanoemulsion adjuvants have been proved efficient, but the relationship between their key properties and the controlled release which greatly affects immune response is still unclear. The present work explores the role of factors such as particle size, the polydispersity index (PDI), stability and the safety of nanoemulsions by optimizing the water concentration, oil phase and modes of carrying, to explain the impact of those key factors above on adjuvant effect. Methods: Isopropyl myristate (IPM), white oil, soybean oil, and grape-kernel oil were chosen as the oil phase to explore their roles in emulsion characteristics and the adjuvant effect. ICR mice were immunized with an emulsion-inactivated H3N2 split influenza vaccine mixture, to compare the nanoemulsion's adjuvant with traditional aluminium hydroxide or complete Freund's adjuvant. Results: Particle size of all the nanoemulsion formed in our experiment ranged from 20 nm to 200 nm and did not change much when diluted with water, while the PDI decreased obviously, indicating that the particles tended to become more dispersive. Formulas with 80% or 85.6% water concentration showed significant higher HAI titer than aluminium hydroxide or complete Freund's adjuvant, and adsorption rather than capsule mode showed higher antigen delivery efficiency. As mentioned about oil phase, G (IPM), F (white oil), H (soybean oil), and I (grape-kernel oil) showed a decreasing trend in their adjuvant efficiency, and nanoemulsion G was the best adjuvant with smaller and uniform particle size. Conclusion: Emulsions with a smaller, uniform particle size had a better adjuvant effect, and the adsorption mode was generally more efficient than the capsule mode. The potential adjuvant order of the different oils was as follows: IPM > white oil > soybean oil > grape-kernel oil.


Assuntos
Adjuvantes Imunológicos/química , Sistemas de Liberação de Medicamentos/métodos , Emulsões/química , Vacinas contra Influenza/administração & dosagem , Nanoestruturas/química , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Animais , Emulsões/administração & dosagem , Emulsões/farmacologia , Feminino , Vírus da Influenza A Subtipo H3N2 , Vacinas contra Influenza/imunologia , Camundongos Endogâmicos ICR , Óleos/química , Infecções por Orthomyxoviridae/prevenção & controle , Tamanho da Partícula , Óleo de Soja/química , Vacinas de Produtos Inativados , Água/química
2.
Emerg Microbes Infect ; 9(1): 664-675, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32193996

RESUMO

The H7N9 viruses have been circulating for six years. The insertion of a polybasic cleavage site in the haemagglutinin (HA) protein of H7N9 has resulted in the emergence of a highly pathogenic (HP) avian influenza virus. Currently, there are limited studies on neutralizing monoclonal antibodies(mAbs) against HP H7N9 AIVs. In this study, mice were immunized with inactivated H7N9 vaccine of A/ZJU01/PR8/2013 to produce murine mAbs. Finally, two murine mAbs against the HA of low pathogenic (LP) virus were produced and characterized. Characterization included determining mAbs binding breadth and affinity, in vitro neutralization capacity, and potential in vivo protection. Two of these mAbs, 1H10 and 2D1, have been identified to have therapeutic and prophylactic efficacy against the HP strain in mouse passive transfer-viral challenge experiments. The mAb 1H10 was most efficacious, even if the treatment-time was as late as 72 h post-infection, or the therapeutic dose was as low as 1 mg/kg; and it was confirmed to have haemagglutination inhibition and neutralizing activity on both LP-and HP-H7N9 strains. Further study indicated that the protection provided by 2D1 was mediated by antibody-dependent cellular cytotoxicity. The mAbs described here provide promising results and merit further development into potential antiviral therapeutics for H7N9 infection.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Subtipo H7N9 do Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/terapia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Antivirais/administração & dosagem , Citotoxicidade Celular Dependente de Anticorpos , Anticorpos Amplamente Neutralizantes/imunologia , Linhagem Celular , Mapeamento de Epitopos , Feminino , Testes de Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Imunização Passiva , Subtipo H7N9 do Vírus da Influenza A/metabolismo , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Testes de Neutralização , Filogenia
3.
Science ; 367(6480)2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-32079747

RESUMO

Current influenza vaccines only confer protection against homologous viruses. We synthesized pulmonary surfactant (PS)-biomimetic liposomes encapsulating 2',3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), an agonist of the interferon gene inducer STING (stimulator of interferon genes). The adjuvant (PS-GAMP) vigorously augmented influenza vaccine-induced humoral and CD8+ T cell immune responses in mice by simulating the early phase of viral infection without concomitant excess inflammation. Two days after intranasal immunization with PS-GAMP-adjuvanted H1N1 vaccine, strong cross-protection was elicited against distant H1N1 and heterosubtypic H3N2, H5N1, and H7N9 viruses for at least 6 months while maintaining lung-resident memory CD8+ T cells. Adjuvanticity was then validated in ferrets. When alveolar epithelial cells (AECs) lacked Sting or gap junctions were blocked, PS-GAMP-mediated adjuvanticity was substantially abrogated in vivo. Thus, AECs play a pivotal role in configuring heterosubtypic immunity.


Assuntos
Materiais Biomiméticos , Vacinas contra Influenza/imunologia , Nanopartículas , Nucleotídeos Cíclicos/administração & dosagem , Infecções por Orthomyxoviridae/prevenção & controle , Surfactantes Pulmonares/imunologia , Vacinação/métodos , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Materiais Biomiméticos/administração & dosagem , Linfócitos T CD8-Positivos/imunologia , Furões , Memória Imunológica , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Subtipo H7N9 do Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Lipossomos , Proteínas de Membrana/agonistas , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Nanopartículas/administração & dosagem , Nucleotídeos Cíclicos/farmacologia , Surfactantes Pulmonares/administração & dosagem
4.
Nat Commun ; 11(1): 791, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32034141

RESUMO

The conserved hemagglutinin (HA) stem has been a focus of universal influenza vaccine efforts. Influenza A group 1 HA stem-nanoparticles have been demonstrated to confer heterosubtypic protection in animals; however, the protection does not extend to group 2 viruses, due in part to differences in glycosylation between group 1 and 2 stems. Here, we show that introducing the group 2 glycan at Asn38HA1 to a group 1 stem-nanoparticle (gN38 variant) based on A/New Caledonia/20/99 (H1N1) broadens antibody responses to cross-react with group 2 HAs. Immunoglobulins elicited by the gN38 variant provide complete protection against group 2 H7N9 virus infection, while the variant loses protection against a group 1 H5N1 virus. The N38HA1 glycan thus is pivotal in directing antibody responses by controlling access to group-determining stem epitopes. Precise targeting of stem-directed antibody responses to the site of vulnerability by glycan repositioning may be a step towards achieving cross-group influenza protection.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vacinas contra Influenza/imunologia , Nanopartículas/química , Polissacarídeos/química , Animais , Anticorpos Antivirais/imunologia , Especificidade de Anticorpos , Asparagina/química , Asparagina/metabolismo , Anticorpos Amplamente Neutralizantes/imunologia , Reações Cruzadas , Epitopos/imunologia , Feminino , Glicosilação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Imunoglobulinas/imunologia , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle
5.
Emerg Microbes Infect ; 9(1): 78-87, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31894728

RESUMO

The H7N9 influenza virus has been circulating in China for more than six years. The neuraminidase (NA) has gained great concern for the development of antiviral drugs, therapeutic antibodies, and new vaccines. In this study, we screened seven mouse monoclonal antibodies (mAbs) and compared their protective effects against H7N9 influenza virus. The epitope mapping from escape mutants showed that all the seven mAbs could bind to the head region of the N9 NA close to the enzyme activity sites, and four key sites of N9 NA were reported for the first time. The mAbs D3 and 7H2 could simultaneously inhibit the cleavage of the sialic acid of fetuin protein with large molecular weight and NA-XTD with small molecule weight in the NA inhibition experiment, prevent the formation of virus plaque at a low concentration, and effectively protect the mice from the challenge of the lethal dose of H7N9 virus.


Assuntos
Anticorpos Monoclonais/química , Subtipo H7N9 do Vírus da Influenza A/imunologia , Neuraminidase/antagonistas & inibidores , Neuraminidase/química , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Antígenos Virais , Domínio Catalítico , Linhagem Celular , Cães , Mapeamento de Epitopos , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/prevenção & controle , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/tratamento farmacológico
6.
Nat Commun ; 11(1): 162, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919357

RESUMO

The emergence of drug-resistant influenza type A viruses (IAVs) necessitates the development of novel anti-IAV agents. Here, we target the IAV hemagglutinin (HA) protein using multivalent peptide library screens and identify PVF-tet, a peptide-based HA inhibitor. PVF-tet inhibits IAV cytopathicity and propagation in cells by binding to newly synthesized HA, rather than to the HA of the parental virus, thus inducing the accumulation of HA within a unique structure, the inducible amphisome, whose production from the autophagosome is accelerated by PVF-tet. The amphisome is also produced in response to IAV infection in the absence of PVF-tet by cells overexpressing ABC transporter subfamily A3, which plays an essential role in the maturation of multivesicular endosomes into the lamellar body, a lipid-sorting organelle. Our results show that the inducible amphisomes can function as a type of organelle-based anti-viral machinery by sequestering HA. PVF-tet efficiently rescues mice from the lethality of IAV infection.


Assuntos
Antivirais/farmacologia , Hemaglutininas Virais/metabolismo , Vírus da Influenza A/crescimento & desenvolvimento , Infecções por Orthomyxoviridae/prevenção & controle , Peptídeos/farmacologia , Transportadores de Cassetes de Ligação de ATP/biossíntese , Animais , Autofagossomos/metabolismo , Cães , Avaliação Pré-Clínica de Medicamentos/métodos , Endossomos/metabolismo , Feminino , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Biblioteca de Peptídeos , Células Sf9 , Spodoptera
7.
Am J Pathol ; 190(1): 11-24, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31654637

RESUMO

As influenza viruses continue to jump species barriers to cause human infection, assessments of disease severity and viral replication kinetics in vivo provide crucial information for public health professionals. The ferret model is a valuable resource for evaluating influenza virus pathogenicity; thus, understanding the most effective techniques for sample collection and usage, as well as the full spectrum of attainable data after experimental inoculation in this species, is paramount. This is especially true for scheduled necropsy of virus-infected ferrets, a standard component in evaluation of influenza virus pathogenicity, as necropsy findings can provide important information regarding disease severity and pathogenicity that is not otherwise available from the live animal. In this review, we describe the range of influenza viruses assessed in ferrets, the measures of experimental disease severity in this model, and optimal sample collection during necropsy of virus-infected ferrets. Collectively, this information is critical for assessing systemic involvement after influenza virus infection in mammals.


Assuntos
Modelos Animais de Doenças , Vírus da Influenza A/patogenicidade , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Pesquisa Biomédica , Furões , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia
8.
Rev Sci Tech ; 38(2): 601-613, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31866673

RESUMO

Chile faced a severe aquatic animal health crisis in 2007 that affected the production of Atlantic salmon (Salmo salar) after an outbreak of infectious salmon anaemia (ISA). The outbreak had a considerable national economic impact. The response was led by the Competent Authority, the National Fisheries and Aquaculture Service (Sernapesca), which immediately implemented surveillance and control actions to mitigate the crisis. At the end of the initial response, the Competent Authority, together with the industry, set out a roadmap to return to sustainable salmon production. The success of the response was due to early detection and the implementation of biosecurity and control measures at all stages of production and control. These measures underpin the sanitary management model for aquaculture. The Chilean Veterinary Service has analysed critical health measures for salmon production and concluded that there has been an improvement in fish health, as evidenced by decreased mortalities, reduced use of antimicrobials, and improved management and control of prevalent diseases, such as salmon rickettsial syndrome (piscirickettsiosis), caligidosis and ISA. Improvements in health have contributed to increased harvests over time, with the largest monthly harvest for Atlantic salmon being achieved in January-February 2018, with 120,000 tonnes. The ISA crisis provided salutary lessons for the continued recovery and sustainability of Chile's salmon sector. The crisis highlighted the importance of strengthened Veterinary Services and public-private links, as well as a collaborative relationship with research entities and training centres. It was also important to enact new regulations to ensure recovery and sustainability. Fundamentally, the response to this crisis was based upon having good baseline surveillance already in place, supported by a Veterinary Service trained to manage emergency disease outbreaks.


Assuntos
Doenças dos Peixes , Isavirus , Infecções por Orthomyxoviridae/veterinária , Salmão/virologia , Animais , Aquicultura , Chile , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/prevenção & controle , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/prevenção & controle
9.
PLoS One ; 14(11): e0225063, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31725776

RESUMO

Correlates of protection (CoP) are invaluable for iterative vaccine design studies, especially in pursuit of complex vaccines such as a universal influenza vaccine (UFV) where a single antigen is optimized to elicit broad protection against many viral antigenic variants. Since broadly protective antibodies against influenza virus often exhibit mutational evidence of prolonged diversification, we studied germinal center (GC) kinetics in hemagglutinin (HA) immunized mice. Here we report that as early as 4 days after secondary immunization, the expansion of HA-specific GC B cells inversely correlated to protection against influenza virus challenge, induced by the antigen. In contrast, follicular T helper (TFH) cells did not expand differently after boost vaccination, suggestive of a B-cell intrinsic difference in activation and differentiation inferred by protective antigen properties. Importantly, differences in antigen dose only affected GC B-cell frequencies after primary immunization. The absence of accompanying differences in total anti-HA or epitope-specific antibody levels induced by vaccines of different efficacy suggests that the GC B-cell response upon revaccination represents an early and unique marker of protection that may significantly accelerate the pre-clinical phase of vaccine development.


Assuntos
Biomarcadores , Centro Germinativo/imunologia , Memória Imunológica , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Centro Germinativo/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Imunização , Camundongos
10.
PLoS Pathog ; 15(11): e1008098, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31730644

RESUMO

Influenza A viruses (IAVs) encode their genome across eight, negative sense RNA segments. During viral assembly, the failure to package all eight segments, or packaging a mutated segment, renders the resulting virion incompletely infectious. It is known that the accumulation of these defective particles can limit viral disease by interfering with the spread of fully infectious particles. In order to harness this phenomenon therapeutically, we defined which viral packaging signals were amenable to duplication and developed a viral genetic platform which produced replication competent IAVs that require up to two additional artificial genome segments for full infectivity. The modified and artificial genome segments propagated by this approach are capable of acting as "decoy" segments that, when packaged by coinfecting wild-type viruses, lead to the production of non-infectious viral particles. Although IAVs which require 10 genomic segments for full infectivity are able to replicate themselves and spread in vivo, their genomic modifications render them avirulent in mice. Administration of these viruses, both prophylactically and therapeutically, was able to rescue animals from a lethal influenza virus challenge. Together, our results show that replicating IAVs designed to propagate and spread defective genomic segments represent a potent anti-influenza biological therapy that can target the conserved process of particle assembly to limit viral disease.


Assuntos
Antivirais/farmacologia , Genoma Viral , Vírus da Influenza A/genética , Infecções por Orthomyxoviridae/prevenção & controle , Proteínas Virais/genética , Replicação Viral , Animais , Cães , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/virologia , Vírion , Montagem de Vírus
11.
Res Vet Sci ; 127: 47-56, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31677416

RESUMO

Recent studies have questioned the effect of maternal derived antibodies (MDAs) to protect piglets against infection with influenza A virus (IAV). The lack of protection against IAV infections provided by MDAs has encouraged alternative vaccination strategies targeting young piglets in an attempt to stimulate an early antibody response. There is a lack of studies documenting the efficacy of piglet vaccination. In the present study, we monitored a group of vaccinated and non-vaccinated piglets in a Danish sow herd that initiated piglet vaccination with » dose of an inactivated swine influenza vaccine at the time of castration (day 3-4). A total of 160 piglets from 11 sows were included and either vaccinated with 0.5 mL inactivated swine influenza vaccine or sham-vaccinated. From week 0 until week 6, all included piglets were clinically examined and nasal swapped once per week and weighed at weeks 0, 3 and 6. Blood samples were collected from sows at week 0 and from piglets at week 3. Vaccination of piglets had limited effect on clinical signs, body weight, antibody development and viral shedding, within the first 6 weeks of life. At least 50% of all pigs of each treatment group tested positive for IAV at week 2, and very early onset of IAV shedding was observed. In total, 18 pigs were IAV positive in nasal swabs for more than one consecutive sampling time indicating prolonged shedding and 14 pigs were IAV positive with negative samplings in between indicating re-infection with the same IAV strain.


Assuntos
Vírus da Influenza A/efeitos dos fármacos , Vacinas contra Influenza/farmacologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Animais , Anticorpos Antivirais/sangue , Formação de Anticorpos , Dinamarca , Vírus da Influenza A/fisiologia , Vacinas contra Influenza/administração & dosagem , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Suínos , Doenças dos Suínos/virologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/farmacologia , Eliminação de Partículas Virais
12.
Vet Microbiol ; 239: 108492, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31767065

RESUMO

Swine influenza A virus (IAV-S) infections are a major cause of economic losses for the swine industry. The vast genetic and antigenic diversity often results in mismatch between the vaccine and field strains, necessitating frequent updates of vaccines. Inactivated IAV-S vaccines are of questionable efficacy. Intra-nasally administered live vaccines are more effective but are associated with safety concerns. The objective of this study was to develop a first-generation vaccine which combines the safety and efficacy advantages of inactivated and attenuated vaccines respectively. The approach targeted fragmentation of viral nucleic acids while preserving structure. Hence, cultures of influenza A/CA/04/09 H1N1 were exposed to 44 °C for 10 min. to reversibly denature the capsid, followed by RNase treatment to digest the genomic RNA and then refolded at lower temperatures. As targeted, treated virions retained an intact structure and were not detected in the first passage in infected cells. To improve intra-nasal delivery of the vaccine antigen, the vaccine antigen was delivered in porcine lung surfactant. Both the treated vaccine alone or vaccine in combination with the surfactant elicited strong anti-HA and virus neutralizing antibodies, protection against viral shedding and lung lesions in 3-week-old piglets. There were no significant differences between the groups. Vaccine viral replication was not detected in the vaccinated pigs. The described approach can advance current immunization practices against swine influenza viruses due to the relative simplicity, high efficacy and safety and ease of adaptation to newly emerging field strains.


Assuntos
Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/veterinária , Tensoativos/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas de Produtos Inativados/imunologia , Administração Intranasal/veterinária , Animais , Anticorpos Antivirais/sangue , Temperatura Alta , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas Atenuadas/administração & dosagem , Vacinas de Produtos Inativados/administração & dosagem
13.
Cell Host Microbe ; 26(6): 729-738.e4, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31757767

RESUMO

Influenza virus neuraminidase (NA) is a major target for small-molecule antiviral drugs. Antibodies targeting the NA surface antigen could also inhibit virus entry and egress to provide host protection. However, our understanding of the nature and range of target epitopes is limited because of a lack of human antibody structures with influenza neuraminidase. Here, we describe crystal and cryogenic electron microscopy (cryo-EM) structures of NAs from human-infecting avian H7N9 viruses in complex with five human anti-N9 antibodies, systematically defining several antigenic sites and antibody epitope footprints. These antibodies either fully or partially block the NA active site or bind to epitopes distant from the active site while still showing neuraminidase inhibition. The inhibition of antibodies to NAs was further analyzed by glycan array and solution-based NA activity assays. Together, these structural studies provide insights into protection by anti-NA antibodies and templates for the development of NA-based influenza virus vaccines and therapeutics.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Epitopos/ultraestrutura , Neuraminidase , Infecções por Orthomyxoviridae/tratamento farmacológico , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/ultraestrutura , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/ultraestrutura , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/ultraestrutura , Antivirais/imunologia , Microscopia Crioeletrônica , Epitopos/imunologia , Epitopos/metabolismo , Humanos , Subtipo H7N9 do Vírus da Influenza A/imunologia , Vacinas contra Influenza , Neuraminidase/química , Neuraminidase/ultraestrutura , Infecções por Orthomyxoviridae/prevenção & controle , Proteínas Virais/química , Proteínas Virais/ultraestrutura
14.
Cell Host Microbe ; 26(6): 715-728.e8, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31757769

RESUMO

H7N9 avian influenza virus causes severe infections and might have the potential to trigger a major pandemic. Molecular determinants of human humoral immune response to N9 neuraminidase (NA) proteins, which exhibit unusual features compared with seasonal influenza virus NA proteins, are ill-defined. We isolated 35 human monoclonal antibodies (mAbs) from two H7N9 survivors and two vaccinees. These mAbs react to NA in a subtype-specific manner and recognize diverse antigenic sites on the surface of N9 NA, including epitopes overlapping with, or distinct from, the enzyme active site. Despite recognizing multiple antigenic sites, the mAbs use a common mechanism of action by blocking egress of nascent virions from infected cells, thereby providing an antiviral prophylactic and therapeutic protection in vivo in mice. Studies of breadth, potency, and diversity of antigenic recognition from four subjects suggest that vaccination with inactivated adjuvanted vaccine induce NA-reactive responses comparable to that of H7N9 natural infection.


Assuntos
Anticorpos Neutralizantes , Subtipo H7N9 do Vírus da Influenza A/imunologia , Neuraminidase/imunologia , Infecções por Orthomyxoviridae , Liberação de Vírus/efeitos dos fármacos , Animais , Anticorpos Heterófilos/farmacologia , Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , Aves , Epitopos/imunologia , Humanos , Subtipo H7N9 do Vírus da Influenza A/efeitos dos fármacos , Vacinas contra Influenza/imunologia , Influenza Aviária/prevenção & controle , Influenza Aviária/virologia , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Camundongos , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Profilaxia Pré-Exposição , Vacinação , Vacinas de Produtos Inativados , Proteínas Virais/imunologia
15.
Influenza Other Respir Viruses ; 13(6): 535-546, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31583825

RESUMO

Ferrets are a well-established model for studying both the pathogenesis and transmission of human respiratory viruses and evaluation of antiviral vaccines. Advanced immunological studies would add substantial value to the ferret models of disease but are hindered by the low number of ferret-reactive reagents available for flow cytometry and immunohistochemistry. Nevertheless, progress has been made to understand immune responses in the ferret model with a limited set of ferret-specific reagents and assays. This review examines current immunological insights gained from the ferret model across relevant human respiratory diseases, with a focus on influenza viruses. We highlight key knowledge gaps that need to be bridged to advance the utility of ferrets for immunological studies.


Assuntos
Modelos Animais de Doenças , Furões/imunologia , Infecções por Orthomyxoviridae/imunologia , Orthomyxoviridae/imunologia , Animais , Humanos , Imunidade/genética , Imunidade/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Influenza Humana/transmissão , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/transmissão , Viroses/imunologia , Viroses/prevenção & controle , Viroses/transmissão
16.
Vet Microbiol ; 237: 108401, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31585639

RESUMO

Influenza results in significant economic loss in the swine industry each year. A broadly protective swine influenza vaccine would have the dual benefit of protecting pigs from influenza A viruses (IAVs) and limiting their possible zoonotic transmission to humans. In this study, we developed polyanhydride nanoparticles-based swine influenza vaccine (KAg + CpG-nanovaccine) co-encapsulating inacticated/killed soluble antigen (KAg) and Toll-like receptor (TLR)-9 agonist (CpG-ODN). The immunogenicity and protective efficacy of KAg + CpG-nanovaccine was compared with KAg vaccine containing five-times greater quantity of antigens following heterologous virus challenge. Prime-boost intranasally delivered KAg + CpG-nanovaccine induced significantly higher levels of cross-reactive antigen-specific IgA antibody responses in the nasal cavity, greater lymphoproliferative response in peripheral blood mononuclear cells (PBMCs), and higher IFN-γ secretion during antigen-induced recall responses of PBMCs and tracheobronchial lymph nodes cells compared to those immunized with KAg alone. Importantly, KAg + CpG-nanovaccine provided better protective efficacy through a significant reduction in influenza-induced fever, 16-fold reduction of nasal virus shedding and 80-fold reduction in lung virus titers compared to those immunized with soluble KAg. Our results indicated that CpG-ODN-adjuvanted polyanhydride nanovaccine can induce higher mucosal antibody and cellular immune responses in pigs; and provide better protection as compared with intranasally delivered soluble KAg.


Assuntos
Vacinas contra Influenza/imunologia , Oligodesoxirribonucleotídeos/farmacologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Adjuvantes Imunológicos , Administração Intranasal , Animais , Anticorpos Antivirais , Antígenos Virais/imunologia , Feminino , Imunidade nas Mucosas , Imunoglobulina A/imunologia , Interferon gama/metabolismo , Leucócitos Mononucleares , Masculino , Nanoestruturas , Oligodesoxirribonucleotídeos/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Polianidridos , Suínos , Vacinas de Produtos Inativados/imunologia
17.
Vet Ital ; 55(3): 195-201, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31599544

RESUMO

Each year millions of people are infected by influenza viruses, and this causes a substantial economic and health burden on our society. Influenza epidemics and pandemics are attributable to the ongoing evolution of influenza viruses through antigenic drift and shift, respectively. One of the reasons for the continuous circulation of influenza viruses in the human population is the incomplete protection conferred by currently available seasonal influenza vaccines against possible arising drifted or shifted influenza strains. Recently, tremendous efforts have been focused on the development of a more effective broadly reactive or universal influenza vaccine. The main objective of underdevelopment vaccines is to protect the human population not only from currently circulating virus strains but also from possible future variants without the need for their continuous update. Different approaches have been developed to reach this goal and elicit an effective and cross-protective immune response. Among these, consensus-based prophylactic approaches to effectively prevent influenza infections are the major focus of this review.


Assuntos
Hemaglutininas/uso terapêutico , Influenza Humana/prevenção & controle , Infecções por Orthomyxoviridae/veterinária , Orthomyxoviridae/efeitos dos fármacos , Animais , Humanos , Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/prevenção & controle
18.
PLoS Pathog ; 15(10): e1008072, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31603951

RESUMO

Respiratory viral infections contribute substantially to global infant losses and disproportionately affect preterm neonates. Using our previously established neonatal murine model of influenza infection, we demonstrate that three-day old mice are exceptionally sensitive to influenza virus infection and exhibit high mortality and viral load. Intranasal pre- and post-treatment of neonatal mice with Lactobacillus rhamnosus GG (LGG), an immune modulator in respiratory viral infection of adult mice and human preterm neonates, considerably improves neonatal mice survival after influenza virus infection. We determine that both live and heat-killed intranasal LGG are equally efficacious in protection of neonates. Early in influenza infection, neonatal transcriptional responses in the lung are delayed compared to adults. These responses increase by 24 hours post-infection, demonstrating a delay in the kinetics of the neonatal anti-viral response. LGG pretreatment improves immune gene transcriptional responses during early infection and specifically upregulates type I IFN pathways. This is critical for protection, as neonatal mice intranasally pre-treated with IFNß before influenza virus infection are also protected. Using transgenic mice, we demonstrate that the protective effect of LGG is mediated through a MyD88-dependent mechanism, specifically via TLR4. LGG can improve both early control of virus and transcriptional responsiveness and could serve as a simple and safe intervention to protect neonates.


Assuntos
Vírus da Influenza A/fisiologia , Lactobacillus rhamnosus/crescimento & desenvolvimento , Pulmão/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Administração Intranasal , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Pulmão/virologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia
19.
Int J Nanomedicine ; 14: 7533-7548, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571862

RESUMO

Background: The influenza A virus (IAV) is known for its high variability and poses a huge threat to the health of humans and animals. Pigs play a central role in the cross-species reassortment of IAV. Ectodomain of matrix protein 2 (M2e) is the most conserved protective antigen in IAV and can be used to develop nanovaccines through nanoparticles displaying to increase its immunogenicity. However, the high immunogenicity of nanoparticles can cause the risk of off-target immune response, and excess unwanted antibodies may interfere with the protective efficacy of M2e-specific antibodies. Therefore, it is necessary to select reasonable nanoparticles to make full use of antibodies against nanoparticles while increasing the level of M2e-specific antibodies. Porcine circovirus type 2 (PCV2) is the most susceptible virus in pigs and can promote IAV infection. It is meaningful to develop a vaccine that can simultaneously control swine influenza virus (SIV) and PCV2. Methods: In the present study, M2e of different copy numbers were inserted into the capsid (Cap) protein of PCV2 and expressed in Escherichia coli to form self-assembled chimeric virus-like particles (VLPs) nanovaccine. BALB/c mice and pigs were immunized with these nanovaccines to explore optimal anti-IAV and anti-PCV2 immunity. Results: Cap is capable of carrying at least 81 amino acid residues (three copies of M2e) at its C-terminal without impairing VLPs formation. Cap-3M2e VLPs induced the highest levels of M2e-specific immune responses, conferring protection against lethal challenge of IAVs from different species and induced specific immune responses consistent with PCV2 commercial vaccines in mice. In addition, Cap-3M2e VLPs induced high levels of M2e-specific antibodies and PCV2-specific neutralizing antibodies in pigs. Conclusion: Cap-3M2e VLP is an economical and promising bivalent nanovaccine, which provides dual protection against IAV and PCV2.


Assuntos
Circovirus/imunologia , Vírus da Influenza A/imunologia , Nanopartículas/uso terapêutico , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Especificidade de Anticorpos/imunologia , Aves/virologia , Proteínas do Capsídeo/química , Proliferação de Células , Citocinas/metabolismo , Cães , Feminino , Humanos , Imunidade Humoral , Influenza Aviária/imunologia , Influenza Aviária/prevenção & controle , Influenza Aviária/virologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Linfócitos/citologia , Células Madin Darby de Rim Canino , Camundongos Endogâmicos BALB C , Testes de Neutralização , Proteínas Recombinantes/isolamento & purificação , Suínos , Vírion/imunologia , Vírion/ultraestrutura
20.
PLoS One ; 14(9): e0222201, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31553755

RESUMO

Swine influenza virus (SIVs) infections cause a significant economic impact to the pork industry. Moreover, pigs may act as mixing vessel favoring genome reassortment of diverse influenza viruses. Such an example is the pandemic H1N1 (pH1N1) virus that appeared in 2009, harboring a combination of gene segments from avian, pig and human lineages, which rapidly reached pandemic proportions. In order to confront and prevent these possible emergences as well as antigenic drift phenomena, vaccination remains of vital importance. The present work aimed to evaluate a new DNA influenza vaccine based on distinct conserved HA-peptides fused with flagellin and applied together with Diluvac Forte as adjuvant using a needle-free device (IntraDermal Application of Liquids, IDAL®). Two experimental pig studies were performed to test DNA-vaccine efficacy against SIVs in pigs. In the first experiment, SIV-seronegative pigs were vaccinated with VC4-flagellin DNA and intranasally challenged with a pH1N1. In the second study, VC4-flagellin DNA vaccine was employed in SIV-seropositive animals and challenged intranasally with an H3N2 SIV-isolate. Both experiments demonstrated a reduction in the viral shedding after challenge, suggesting vaccine efficacy against both the H1 and H3 influenza virus subtypes. In addition, the results proved that maternally derived antibodies (MDA) did not constitute an obstacle to the vaccine approach used. Moreover, elevated titers in antibodies both against H1 and H3 proteins in serum and in bronchoalveolar lavage fluids (BALFs) was detected in the vaccinated animals along with a markedly increased mucosal IgA response. Additionally, vaccinated animals developed stronger neutralizing antibodies in BALFs and higher inhibiting hemagglutination titers in sera against both the pH1N1 and H3N2 influenza viruses compared to unvaccinated, challenged-pigs. It is proposed that the described DNA-vaccine formulation could potentially be used as a multivalent vaccine against SIV infections.


Assuntos
Vacinas contra Influenza/uso terapêutico , Infecções por Orthomyxoviridae/prevenção & controle , Doenças dos Suínos/prevenção & controle , Vacinas de DNA/uso terapêutico , Animais , Sequência Conservada , Feminino , Hemaglutininas/genética , Hemaglutininas/imunologia , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/imunologia , Masculino , Infecções por Orthomyxoviridae/imunologia , Suínos/imunologia , Suínos/virologia , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Vacinas de DNA/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA