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1.
J Virol ; 89(22): 11190-202, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26311894

RESUMO

UNLABELLED: Avian influenza A viruses have gained increasing attention due to their ability to cross the species barrier and cause severe disease in humans and other mammal species as pigs. H3 and particularly H3N8 viruses, are highly adaptive since they are found in multiple avian and mammal hosts. H3N8 viruses have not been isolated yet from humans; however, a recent report showed that equine influenza A viruses (IAVs) can be isolated from pigs, although an established infection has not been observed thus far in this host. To gain insight into the possibility of H3N8 avian IAVs to cross the species barrier into pigs, in vitro experiments and an experimental infection in pigs with four H3N8 viruses from different origins (equine, canine, avian, and seal) were performed. As a positive control, an H3N2 swine influenza virus A was used. Although equine and canine viruses hardly replicated in the respiratory systems of pigs, avian and seal viruses replicated substantially and caused detectable lesions in inoculated pigs without previous adaptation. Interestingly, antibodies against hemagglutinin could not be detected after infection by hemagglutination inhibition (HAI) test with avian and seal viruses. This phenomenon was observed not only in pigs but also in mice immunized with the same virus strains. Our data indicated that H3N8 IAVs from wild aquatic birds have the potential to cross the species barrier and establish successful infections in pigs that might spread unnoticed using the HAI test as diagnostic tool. IMPORTANCE: Although natural infection of humans with an avian H3N8 influenza A virus has not yet been reported, this influenza A virus subtype has already crossed the species barrier. Therefore, we have examined the potential of H3N8 from canine, equine, avian, and seal origin to productively infect pigs. Our results demonstrated that avian and seal viruses replicated substantially and caused detectable lesions in inoculated pigs without previous adaptation. Surprisingly, we could not detect specific antibodies against hemagglutinin in any H3N8-infected pigs. Therefore, special attention should be focused toward viruses of the H3N8 subtype since they could behave as stealth viruses in pigs.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H3N8/patogenicidade , Infecções por Orthomyxoviridae/imunologia , Replicação Viral/fisiologia , Animais , Anticorpos Antivirais/sangue , Caniformia , Bovinos , Embrião de Galinha , Cães , Feminino , Cavalos , Humanos , Vírus da Influenza A Subtipo H3N2/patogenicidade , Vírus da Influenza A Subtipo H3N8/genética , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/virologia , Suínos , Traqueia/virologia
2.
J Virol ; 88(22): 13436-46, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25210184

RESUMO

UNLABELLED: Influenza pandemics occur when influenza A viruses (IAV) adapted to other host species enter humans and spread through the population. Pandemics are relatively rare due to host restriction of IAV: strains adapted to nonhuman species do not readily infect, replicate in, or transmit among humans. IAV can overcome host restriction through reassortment or adaptive evolution, and these are mechanisms by which pandemic strains arise in nature. To identify mutations that facilitate growth of avian IAV in humans, we have adapted influenza A/duck/Alberta/35/1976 (H1N1) (dk/AB/76) virus to a high-growth phenotype in differentiated human tracheo-bronchial epithelial (HTBE) cells. Following 10 serial passages of three independent lineages, the bulk populations showed similar growth in HTBE cells to that of a human seasonal virus. The coding changes present in six clonal isolates were determined. The majority of changes were located in the polymerase complex and nucleoprotein (NP), and all isolates carried mutations in the PB2 627 domain and regions of NP thought to interact with PB2. Using reverse genetics, the impact on growth and polymerase activity of individual and paired mutations in PB2 and NP was evaluated. The results indicate that coupling of the mammalian-adaptive mutation PB2 E627K or Q591K to selected mutations in NP further augments the growth of the corresponding viruses. In addition, minimal combinations of three (PB2 Q236H, E627K, and NP N309K) or two (PB2 Q591K and NP S50G) mutations were sufficient to recapitulate the efficient growth in HTBE cells of dk/AB/76 viruses isolated after 10 passages in this substrate. IMPORTANCE: Influenza A viruses adapted to birds do not typically grow well in humans. However, as has been seen recently with H5N1 and H7N9 subtype viruses, productive and virulent infection of humans with avian influenza viruses can occur. The ability of avian influenza viruses to adapt to new host species is a consequence of their high mutation rate that supports their zoonotic potential. Understanding of the adaptation of avian viruses to mammals strengthens public health efforts aimed at controlling influenza. In particular, it is critical to know how readily and through mutation to which functional components avian influenza viruses gain the ability to grow efficiently in humans. Our data show that as few as three mutations, in the PB2 and NP proteins, support robust growth of a low-pathogenic, H1N1 duck isolate in primary human respiratory cells.


Assuntos
Células Epiteliais/virologia , Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H1N1/genética , Mutação , Proteínas de Ligação a RNA/genética , RNA Polimerase Dependente de RNA/genética , Proteínas do Core Viral/genética , Proteínas Virais/genética , Adaptação Biológica , Animais , Linhagem Celular , Análise Mutacional de DNA , Patos , Humanos , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Aviária/virologia , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas do Nucleocapsídeo , Proteínas de Ligação a RNA/metabolismo , RNA Polimerase Dependente de RNA/metabolismo , Recombinação Genética , Genética Reversa , Inoculações Seriadas , Proteínas do Core Viral/metabolismo , Proteínas Virais/metabolismo
3.
Lancet Infect Dis ; 22(7): 1062-1075, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35461522

RESUMO

BACKGROUND: One strategy to develop a universal influenza virus vaccine is to redirect the immune system to the highly conserved haemagglutinin stalk domain by sequentially administering vaccines expressing chimeric (c) haemagglutinins with a conserved stalk domain and divergent head domain, to which humans are naive. We aimed to assess the reactogenicity, safety, and immunogenicity of adjuvanted and unadjuvanted investigational supra-seasonal universal influenza virus vaccines (SUIVs) in healthy young adults. METHODS: In this observer-masked, randomised, controlled, phase 1-2 trial, we recruited adults aged 18-39 years with no clinically significant conditions from six centres in Belgium and the USA. Participants were randomly assigned to ten equally sized groups via an online system with the MATerial Excellence programme. Vaccines contained heterosubtypic group 1 H8, H5, or H11 haemagglutinin heads, an H1 haemagglutinin stalk, and an N1 neuraminidase (cH8/1N1, cH5/1N1, and cH11/1N1; haemagglutinin dose 15 µg/0·5 mL), administered on days 1 and 57, with a month 14 booster. SUIVs were evaluated in the sequences: cH8/1N1-placebo-cH5/1N1, cH5/1N1-placebo-cH8/1N1, or cH8/1N1-cH5/1N1-cH11/1N1, adjuvanted with either AS03 or AS01, or not adjuvanted. The last group received inactivated quadrivalent influenza vaccine (IIV4)-placebo-IIV4. Primary outcomes were safety (analysed in the exposed population) and immunogenicity in terms of the anti-H1 stalk humoral response at 28 days after vaccination (analysed in the per-protocol population, defined as participants who received the study vaccines according to the protocol). This trial is registered with ClinicalTrials.gov, NCT03275389. FINDINGS: Between Sept 25, 2017, and March 26, 2020, 507 eligible participants were enrolled. 468 (92%) participants received at least one dose of study vaccine (exposed population), of whom 244 (52%) were included in the per-protocol population at final analysis at month 26. The safety profiles of all chimeric vaccines were clinically acceptable, with no safety concerns identified. Injection-site pain was the most common adverse event, occurring in 84-96% of participants receiving an adjuvanted SUIV or non-adjuvanted IIV4 and in 40-50% of participants receiving a non-adjuvanted SUIV. Spontaneously reported adverse events up to 28 days after vaccination occurred in 36-60% of participants, with no trends observed for any group. 17 participants had a serious adverse event, none of which were considered to be causally related to the vaccine. Anti-H1 stalk antibody titres were highest in AS03-adjuvanted groups, followed by AS01-adjuvanted and non-adjuvanted groups, and were higher after cH8/1N1 than after cH5/1N1 and after a two-dose primary schedule than after a one-dose schedule. Geometric mean concentrations by ELISA ranged from 21 938·1 ELISA units/mL (95% CI 18 037·8-26 681·8) in the IIV4-placebo-IIV4 group to 116 596·8 ELISA units/mL (93 869·6-144 826·6) in the AS03-adjuvanted cH8/1N1-cH5/1N1-cH11/1N1 group 28 days after the first dose and from 15 105·9 ELISA units/mL (12 007·7-19 003·6) in the non-adjuvanted cH5/1N1-placebo-cH8/1N1 group to 74 639·7 ELISA units/mL (59 986·3-92 872·6) in the AS03-adjuvanted cH8/1N1-cH5/1N1-cH11/1N1 group 28 days after the second dose. INTERPRETATION: The stalk domain seems to be a rational target for development of a universal influenza virus vaccine via administration of chimeric haemagglutinins with head domains to which humans are naive. FUNDING: GlaxoSmithKline Biologicals.


Assuntos
Vacinas contra Influenza , Influenza Humana , Adjuvantes Imunológicos , Adjuvantes Farmacêuticos , Anticorpos Antivirais , Hemaglutininas , Humanos , Imunogenicidade da Vacina , Vírion , Adulto Jovem
4.
Nat Commun ; 13(1): 1536, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35318324

RESUMO

Therapeutic mRNAs and vaccines are being developed for a broad range of human diseases, including COVID-19. However, their optimization is hindered by mRNA instability and inefficient protein expression. Here, we describe design principles that overcome these barriers. We develop an RNA sequencing-based platform called PERSIST-seq to systematically delineate in-cell mRNA stability, ribosome load, as well as in-solution stability of a library of diverse mRNAs. We find that, surprisingly, in-cell stability is a greater driver of protein output than high ribosome load. We further introduce a method called In-line-seq, applied to thousands of diverse RNAs, that reveals sequence and structure-based rules for mitigating hydrolytic degradation. Our findings show that highly structured "superfolder" mRNAs can be designed to improve both stability and expression with further enhancement through pseudouridine nucleoside modification. Together, our study demonstrates simultaneous improvement of mRNA stability and protein expression and provides a computational-experimental platform for the enhancement of mRNA medicines.


Assuntos
COVID-19 , RNA , COVID-19/terapia , Humanos , Pseudouridina/metabolismo , Estabilidade de RNA/genética , RNA Mensageiro/metabolismo
5.
J Virol ; 84(9): 4587-96, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20181702

RESUMO

Human influenza is a seasonal disease associated with significant morbidity and mortality. Influenza vaccination is the most effective means for disease prevention. We have previously shown that mutations in the PB1 and PB2 genes of the live-attenuated influenza vaccine (LAIV) from the cold-adapted (ca) influenza virus A/Ann Arbor/6/60 (H2N2) could be transferred to avian influenza viruses and produce partially attenuated viruses. We also demonstrated that avian influenza viruses carrying the PB1 and PB2 mutations could be further attenuated by stably introducing a hemagglutinin (HA) epitope tag in the PB1 gene. In this work, we wanted to determine whether these modifications would also result in attenuation of a so-called triple reassortant (TR) swine influenza virus (SIV). Thus, the TR influenza A/swine/Wisconsin/14094/99 (H3N2) virus was generated by reverse genetics and subsequently mutated in the PB1 and PB2 genes. Here we show that a combination of mutations in this TR backbone results in an attenuated virus in vitro and in vivo. Furthermore, we show the potential of our TR backbone as a vaccine that provides protection against the 2009 swine-origin pandemic influenza H1N1 virus (S-OIV) when carrying the surface of a classical swine strain. We propose that the availability of alternative backbones to the conventional ca A/Ann Arbor/6/60 LAIV strain could also be useful in epidemic and pandemic influenza and should be considered for influenza vaccine development. In addition, our data provide evidence that the use of these alternative backbones could potentially circumvent the effects of original antigenic sin (OAS) in certain circumstances.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/imunologia , RNA Polimerase Dependente de RNA/genética , Proteínas Virais/genética , Animais , Peso Corporal , Feminino , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Dose Letal Mediana , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Vacinas Atenuadas/imunologia , Ensaio de Placa Viral
6.
Proc Natl Acad Sci U S A ; 105(8): 3064-9, 2008 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-18287069

RESUMO

The 1918 influenza pandemic was exceptionally severe, resulting in the death of up to 50 million people worldwide. Here, we show which virus genes contributed to the replication and virulence of the 1918 influenza virus. Recombinant viruses, in which genes of the 1918 virus were replaced with genes from a contemporary human H1N1 influenza virus, A/Texas/36/91 (Tx/91), were generated. The exchange of most 1918 influenza virus genes with seasonal influenza H1N1 virus genes did not alter the virulence of the 1918 virus; however, substitution of the hemagglutinin (HA), neuraminidase (NA), or polymerase subunit PB1 genes significantly affected the ability of this virus to cause severe disease in mice. The 1918 virus virulence observed in mice correlated with the ability of 1918 recombinant viruses to replicate efficiently in human airway cells. In a second series of experiments, eight 1918 1:7 recombinants were generated, in which each Tx/91 virus gene was individually replaced by a corresponding gene from 1918 virus. Replication capacity of the individual 1:7 reassortant viruses was assessed in mouse lungs and human airway cells. Increased virus titers were observed among 1:7 viruses containing individual 1918 HA, NA, and PB1 genes. In addition, the 1918 PB1:Tx/91 (1:7) virus showed a distinctly larger plaque size phenotype than the small plaque phenotype of the 1918 PA:Tx/91 and 1918 PB2:Tx/91 1:7 reassortants. These results highlight the importance of the 1918 HA, NA, and PB1 genes for optimal virus replication and virulence of this pandemic strain.


Assuntos
Hemaglutininas Virais/genética , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/genética , Influenza Humana/história , Neuraminidase/genética , Proteínas Virais/genética , Replicação Viral/genética , Animais , Feminino , História do Século XX , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Virulência
7.
Vaccines (Basel) ; 9(1)2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33440898

RESUMO

Epidemic or pandemic influenza can annually cause significant morbidity and mortality in humans. We developed novel chimeric hemagglutinin (cHA)-based universal influenza virus vaccines, which contain a conserved HA stalk domain from a 2009 pandemic H1N1 (pH1N1) strain combined with globular head domains from avian influenza A viruses. Our previous reports demonstrated that prime-boost sequential immunizations induced robust antibody responses directed toward the conserved HA stalk domain in ferrets. Herein, we further followed vaccinated animals for one year to compare the efficacy and durability of these vaccines in the preclinical ferret model of influenza. Although all cHA-based immunization regimens induced durable HA stalk-specific and heterosubtypic antibody responses in ferrets, sequential immunization with live-attenuated influenza virus vaccines (LAIV-LAIV) conferred the best protection against upper respiratory tract infection by a pH1N1 influenza A virus. The findings from this study suggest that our sequential immunization strategy for a cHA-based universal influenza virus vaccine provides durable protective humoral and cellular immunity against influenza virus infection.

8.
Nat Med ; 27(1): 106-114, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33288923

RESUMO

Seasonal influenza viruses constantly change through antigenic drift and the emergence of pandemic influenza viruses through antigenic shift is unpredictable. Conventional influenza virus vaccines induce strain-specific neutralizing antibodies against the variable immunodominant globular head domain of the viral hemagglutinin protein. This necessitates frequent re-formulation of vaccines and handicaps pandemic preparedness. In this completed, observer-blind, randomized, placebo-controlled phase I trial (NCT03300050), safety and immunogenicity of chimeric hemagglutinin-based vaccines were tested in healthy, 18-39-year-old US adults. The study aimed to test the safety and ability of the vaccines to elicit broadly cross-reactive antibodies against the hemagglutinin stalk domain. Participants were enrolled into five groups to receive vaccinations with live-attenuated followed by AS03-adjuvanted inactivated vaccine (n = 20), live-attenuated followed by inactivated vaccine (n = 15), twice AS03-adjuvanted inactivated vaccine (n = 16) or placebo (n = 5, intranasal followed by intramuscular; n = 10, twice intramuscular) 3 months apart. Vaccination was found to be safe and induced a broad, strong, durable and functional immune response targeting the conserved, immunosubdominant stalk of the hemagglutinin. The results suggest that chimeric hemagglutinins have the potential to be developed as universal vaccines that protect broadly against influenza viruses.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vacinas contra Influenza/imunologia , Adolescente , Adulto , Anticorpos Antivirais/biossíntese , Humanos , Vacinas contra Influenza/efeitos adversos , Placebos , Adulto Jovem
9.
J Gen Virol ; 91(Pt 9): 2314-21, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20484565

RESUMO

Triple-reassortant swine influenza viruses circulating in North American pigs contain the internal genes derived from swine (matrix, non-structural and nucleoprotein), human [polymerase basic 1 (PB1)] and avian (polymerase acidic and PB2) influenza viruses forming a constellation of genes that is well conserved and is called the triple-reassortant internal gene (TRIG) cassette. In contrast, the external genes [haemagglutinin (HA) and neuraminidase (NA)] are less conserved, reflecting multiple reassortant events that have produced viruses with different combinations of HA and NA genes. This study hypothesized that maintenance of the TRIG cassette confers a selective advantage to the virus. To test this hypothesis, pigs were co-infected with the triple-reassortant H3N2 A/Swine/Texas/4199-2/98 (Tx/98) and the classical H1N1 A/Swine/Iowa/15/1930 viruses and co-housed with a group of sentinel animals. This direct contact group was subsequently moved into contact with a second group of naïve animals. Four different subtypes (H1N1, H1N2, H3N1 and H3N2) of influenza virus were identified in bronchoalveolar lavage fluid collected from the lungs of the experimentally infected pigs, with most of the viruses containing TRIG from the Tx/98 virus. Interestingly, only the intact H3N2 Tx/98 virus was transmitted from the infected pigs to the direct-contact animals and from them to the second contact group of pigs. These results demonstrated that multiple reassortments can occur within a host; however, only specific gene constellations are readily transmissible. It was concluded that certain HA and NA gene pairs, in conjunction with the TRIG cassette, may have a competitive advantage over other combinations for transmission and maintenance in swine.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/patogenicidade , Infecções por Orthomyxoviridae/veterinária , Vírus Reordenados/genética , Vírus Reordenados/patogenicidade , Doenças dos Suínos/transmissão , Doenças dos Suínos/virologia , Animais , Genes Virais , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H1N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Pulmão/virologia , Neuraminidase/genética , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Vírus Reordenados/isolamento & purificação , Sus scrofa , Suínos
10.
J Virol ; 83(4): 1742-53, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19073731

RESUMO

Due to the high mortality associated with recent, widely circulating strains of H5N1 influenza virus in poultry, the recurring introduction of H5N1 viruses from birds to humans, and the difficulties in H5N1 eradication by elimination of affected flocks, an effective vaccine against HPAI (highly pathogenic avian influenza) is highly desirable. Using reverse genetics, a set of experimental live attenuated vaccine strains based on recombinant H5N1 influenza virus A/Viet Nam/1203/04 was generated. Each virus was attenuated through expression of a hemagglutinin protein in which the polybasic cleavage site had been removed. Viruses were generated which possessed a full-length NS1 or a C-terminally truncated NS1 protein of 73, 99, or 126 amino acids. Viruses with each NS genotype were combined with a PB2 polymerase gene which carried either a lysine or a glutamic acid at position 627. We predicted that glutamic acid at position 627 of PB2 would attenuate the virus in mammalian hosts, thus increasing the safety of the vaccine. All recombinant viruses grew to high titers in 10-day-old embryonated chicken eggs but were attenuated in mammalian cell culture. Induction of high levels of beta interferon by all viruses possessing truncations in the NS1 protein was demonstrated by interferon bioassay. The viruses were each found to be highly attenuated in a mouse model. Vaccination with a single dose of any virus conferred complete protection from death upon challenge with a mouse lethal virus expressing H5N1 hemagglutinin and neuraminidase proteins. In a chicken model, vaccination with a single dose of a selected virus encoding the NS1 1-99 protein completely protected chickens from lethal challenge with homologous HPAI virus A/Viet Nam/1203/04 (H5N1) and provided a high level of protection from a heterologous virus, A/egret/Egypt/01/06 (H5N1). Thus, recombinant influenza A/Viet Nam/1203/04 viruses attenuated through the introduction of mutations in the hemagglutinin, NS1, and PB2 coding regions display characteristics desirable for live attenuated vaccines and hold potential as vaccine candidates in poultry as well as in mammalian hosts.


Assuntos
Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Influenza Aviária/imunologia , Influenza Aviária/prevenção & controle , Substituição de Aminoácidos/genética , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Virus da Influenza A Subtipo H5N1/crescimento & desenvolvimento , Influenza Aviária/virologia , Interferon beta/imunologia , Camundongos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , RNA Polimerase Dependente de RNA/genética , Recombinação Genética , Deleção de Sequência , Análise de Sobrevida , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Proteínas não Estruturais Virais/genética , Proteínas Virais/genética
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