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Restori KH, Septer KM, Field CJ, Patel DR, VanInsberghe D, Raghunathan V, Lowen AC, Sutton TC. Risk assessment of a highly pathogenic H5N1 influenza virus from mink. Nat Commun 2024; 15:4112. [PMID: 38750016 PMCID: PMC11096306 DOI: 10.1038/s41467-024-48475-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/24/2024] [Indexed: 05/18/2024] Open
Abstract
Outbreaks of highly pathogenic H5N1 clade 2.3.4.4b viruses in farmed mink and seals combined with isolated human infections suggest these viruses pose a pandemic threat. To assess this threat, using the ferret model, we show an H5N1 isolate derived from mink transmits by direct contact to 75% of exposed ferrets and, in airborne transmission studies, the virus transmits to 37.5% of contacts. Sequence analyses show no mutations were associated with transmission. The H5N1 virus also has a low infectious dose and remains virulent at low doses. This isolate carries the adaptive mutation, PB2 T271A, and reversing this mutation reduces mortality and airborne transmission. This is the first report of a H5N1 clade 2.3.4.4b virus exhibiting direct contact and airborne transmissibility in ferrets. These data indicate heightened pandemic potential of the panzootic H5N1 viruses and emphasize the need for continued efforts to control outbreaks and monitor viral evolution.
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Affiliation(s)
- Katherine H Restori
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, PA, USA
- Emory Center of Excellence of Influenza Research and Response (CEIRR), University Park, PA, USA
| | - Kayla M Septer
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, PA, USA
- The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Cassandra J Field
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, PA, USA
- Emory Center of Excellence of Influenza Research and Response (CEIRR), University Park, PA, USA
- The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Devanshi R Patel
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, PA, USA
- The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - David VanInsberghe
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
- Emory Center of Excellence of Influenza Research and Response (CEIRR), Atlanta, GA, USA
| | - Vedhika Raghunathan
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
- Emory Center of Excellence of Influenza Research and Response (CEIRR), Atlanta, GA, USA
| | - Anice C Lowen
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
- Emory Center of Excellence of Influenza Research and Response (CEIRR), Atlanta, GA, USA
| | - Troy C Sutton
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, PA, USA.
- Emory Center of Excellence of Influenza Research and Response (CEIRR), University Park, PA, USA.
- The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, USA.
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Joaquín Cáceres C, Claire Gay L, Jain A, Mejías TD, Cardenas M, Seibert B, Faccin FC, Cowan B, Geiger G, Baker AV, Carnaccini S, Huw Davies D, Rajao DS, Perez DR. FLUAV RAM-IGIP: A modified live influenza virus vaccine that enhances humoral and mucosal responses against influenza. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576908. [PMID: 38328128 PMCID: PMC10849573 DOI: 10.1101/2024.01.23.576908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Current influenza A vaccines fall short, leaving both humans and animals vulnerable. To address this issue, we have developed attenuated modified live virus (MLV) vaccines against influenza using genome rearrangement techniques targeting the internal gene segments of FLUAV. The rearranged M2 (RAM) strategy involves cloning the M2 ORF downstream of the PB1 ORF in segment 2 and incorporating multiple early stop codons within the M2 ORF in segment 7. Additionally, the IgA-inducing protein (IGIP) coding region was inserted into the HA segment to further attenuate the virus and enhance protective mucosal responses. RAM-IGIP viruses exhibit similar growth rates to wild type (WT) viruses in vitro and remain stable during multiple passages in cells and embryonated eggs. The safety, immunogenicity, and protective efficacy of the RAM-IGIP MLV vaccine against the prototypical 2009 pandemic H1N1 strain A/California/04/2009 (H1N1) (Ca/04) were evaluated in Balb/c mice and compared to a prototypic cold-adapted live attenuated virus vaccine. The results demonstrate that the RAM-IGIP virus exhibits attenuated virulence in vivo. Mice vaccinated with RAM-IGIP and subsequently challenged with an aggressive lethal dose of the Ca/04 strain exhibited complete protection. Analysis of the humoral immune response revealed that the inclusion of IGIP enhanced the production of neutralizing antibodies and augmented the antibody-dependent cellular cytotoxicity response. Similarly, the RAM-IGIP potentiated the mucosal immune response against various FLUAV subtypes. Moreover, increased antibodies against NP and NA responses were observed. These findings support the development of MLVs utilizing genome rearrangement strategies in conjunction with the incorporation of immunomodulators. IMPORTANCE Current influenza vaccines offer suboptimal protection, leaving both humans and animals vulnerable. Our novel attenuated MLV vaccine, built by rearranging FLUAV genome segments and incorporating the IgA-inducing protein, shows promising results. This RAM-IGIP vaccine exhibits safe attenuation, robust immune responses, and complete protection against lethal viral challenge in mice. Its ability to stimulate broad-spectrum humoral and mucosal immunity against diverse FLUAV subtypes makes it a highly promising candidate for improved influenza vaccines.
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Chen J, Wang J, Zhu H, Zhang Y, Sun J, Wang W, Wei C, Zhong H, Dong M. Generation of a Live Attenuated Influenza A Vaccine Using Chemical-Triggered Intein. ACS Synth Biol 2023; 12:1686-1695. [PMID: 37196336 DOI: 10.1021/acssynbio.3c00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Noticeable morbidity and mortality can be caused by influenza A virus in humans. Conventional live attenuated influenza vaccine (LAIV) is one of the main strategies to control the spread of influenza, but its protective efficacy is often limited by its suboptimal immunogenicity and safety. Therefore, a new type of LAIV that can overcome the shortage of existing vaccines is urgently needed. Here, we report a novel method to construct the recombinant influenza A virus (IAV) regulated by small molecules. By inserting 4-hydroxytamoxifen (4-HT)-dependent intein into the polymerase acidic (PA) protein of IAV, a series of 4-HT-dependent recombinant viruses were generated and screened. Among them, the S218 recombinant virus strain showed excellent 4-HT dependent replication characteristics both in vitro and in vivo. Further immunological evaluation indicated that the 4-HT-dependent viruses were highly attenuated in the host and could elicit robust humoral, mucosal, and cellular immunity against the challenge of homologous viruses. The attenuated strategies presented here could also be broadly applied to the development of vaccines against other pathogens.
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Affiliation(s)
- Ji Chen
- School of Pharmacy, Qingdao University, Qingdao 266021, China
- Department of Genetic Engineering, Beijing Institute of Biotechnology, Beijing 100071, China
| | - Jinyu Wang
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Hongyu Zhu
- School of Pharmacy, Qingdao University, Qingdao 266021, China
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao 266021, China
| | - Yang Zhang
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Jin Sun
- School of Pharmacy, Qingdao University, Qingdao 266021, China
- Department of Genetic Engineering, Beijing Institute of Biotechnology, Beijing 100071, China
| | - Wei Wang
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Congwen Wei
- Department of Genetic Engineering, Beijing Institute of Biotechnology, Beijing 100071, China
| | - Hui Zhong
- Department of Genetic Engineering, Beijing Institute of Biotechnology, Beijing 100071, China
| | - Mingxin Dong
- School of Pharmacy, Qingdao University, Qingdao 266021, China
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Rajao DS, Zanella GC, Wymore Brand M, Khan S, Miller ME, Ferreri LM, Caceres CJ, Cadernas-Garcia S, Souza CK, Anderson TK, Gauger PC, Vincent Baker AL, Perez DR. Live attenuated influenza A virus vaccine expressing an IgA-inducing protein protects pigs against replication and transmission. FRONTIERS IN VIROLOGY 2023. [DOI: 10.3389/fviro.2023.1042724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
IntroductionThe rapid evolution of influenza A viruses (FLUAV) complicates disease control for animal and public health. Although vaccination is an effective way to control influenza, available vaccines for use in swine result in limited protection against the antigenically distinct FLUAV that currently co-circulate in pigs. Vaccines administered parenterally usually stimulate IgG antibodies but not strong mucosal IgA or cell-mediated responses, which are typically more cross-reactive.MethodsWe developed a live attenuated influenza virus (LAIV) vaccine containing IgA-inducing protein (IGIP) as a molecular marker and immunomodulator. This Flu-IGIP vaccine was tested in a bivalent formulation (H1N1 and H3N2) against challenge with antigenically drifted viruses in pigs. Pigs were vaccinated intranasally with either a bivalent Flu-IGIP or a bivalent Flu-att (control without IGIP) and boosted two weeks later. Three weeks post boost, pigs were challenged with antigenically drifted H1N1 or H3N2 virus.ResultsVaccinated pigs had increased numbers of influenza-specific IgA-secreting cells in PBMC two weeks post boost and higher numbers of total and influenza-specific IgA-secreting cells in bronchoalveolar lavage fluid (BALF) 5 days post inoculation (dpi) compared to naïve pigs. Pigs vaccinated with both Flu-IGIP and Flu-att shed significantly less virus after H1N1 or H3N2 challenge compared to non-vaccinated pigs. Vaccination with Flu-att reduced respiratory transmission, while Flu-IGIP fully blocked transmission regardless of challenge virus. Both Flu-IGIP and Flu-att vaccines reduced virus replication in the lungs and lung lesions after inoculation with either virus. IgG and IgA levels in BALF and nasal wash of vaccinated pigs were boosted after inoculation as soon as 5 dpi and remained high at 14 dpi.ConclusionOur results indicate that Flu-IGIP leads to protection from clinical signs, replication and shedding after antigenically drifted influenza virus infection.
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Cherepovich BS, Rtishchev AA, Akopova II, Borisova OV, Kost VY, Kutuzova NM, Markushin SG. Comparative study of the biological properties of influenza А virus mutants obtained by site-specific mutagenesis and the live influenza reassortant vaccine variant. JOURNAL OF MICROBIOLOGY, EPIDEMIOLOGY AND IMMUNOBIOLOGY 2022. [DOI: 10.36233/0372-9311-239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The aim of study was to carry out comparative investigation of biological properties of site-specific mutants of Influenza A virus and variant of live cold-adapted (CA) influenza reassortant vaccine.
Materials and methods. The genetic stability of site-specific mutants (SSM) of the A/WSN/33 (H1N1) strain with ts (temperature sensitive)-mutations in polymerase genes was studied using a stress-test in MadinDarby Canine Kidney (MDCK) culture. A comparative study of immunogenicity of U2 and M26 mutants with the high genetic stability and the CA-reassortant with similar surface proteins was carried out. The increase in the antibody titer was investigated using enzyme-linked immunosorbent assay and the reaction of delayed hemagglutination. Ability of the studied viruses to induce type 1 interferon in A549 cells was determined using real-time polymerase chain reaction (real-time PCR).
Results. It was shown that U2 and M26 mutants, which have 3 ts-mutations or more in polymerase genes have high genetic stability. It was found that U2 and M26 mutants induced a higher antibody titers than the CA reassortant in mice following the intranasal immunization. The ability of site-specific mutants and CA reassortant to induce type 1 interferon was also investigated. Mutants U2 and M26 increased the level of interferon to a greater extent than the CA-reassortant.
Conclusion. The data obtained indicate that SSM U2 and M26 with 3 ts-mutations or more in the genome have a significant level of genetic stability. Mutants U2 and M26 have a higher immunogenicity and a higher ability to induce interferon in comparison with the CA reassortant. These facts allow us to conclude that SSM of the influenza virus with a set of mutations in polymerase genes can be considered as promising candidates for live influenza vaccines.
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Mo JS, Abente EJ, Cardenas Perez M, Sutton TC, Cowan B, Ferreri LM, Geiger G, Gauger PC, Perez DR, Vincent Baker AL, Rajao DS. Transmission of Human Influenza A Virus in Pigs Selects for Adaptive Mutations on the HA Gene. J Virol 2022; 96:e0148022. [PMID: 36317880 PMCID: PMC9682980 DOI: 10.1128/jvi.01480-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 10/01/2022] [Indexed: 11/24/2022] Open
Abstract
Influenza A viruses (FLUAV) cause respiratory diseases in many host species, including humans and pigs. The spillover of FLUAV between swine and humans has been a concern for both public health and the swine industry. With the emergence of the triple reassortant internal gene (TRIG) constellation, establishment of human-origin FLUAVs in pigs has become more common, leading to increased viral diversity. However, little is known about the adaptation processes that are needed for a human-origin FLUAV to transmit and become established in pigs. We generated a reassortant FLUAV (VIC11pTRIG) containing surface gene segments from a human FLUAV strain and internal gene segments from the 2009 pandemic and TRIG FLUAV lineages and demonstrated that it can replicate and transmit in pigs. Sequencing and variant analysis identified three mutants that emerged during replication in pigs, which were mapped near the receptor binding site of the hemagglutinin (HA). The variants replicated more efficiently in differentiated swine tracheal cells compared to the virus containing the wildtype human-origin HA, and one of them was present in all contact pigs. These results show that variants are selected quickly after replication of human-origin HA in pigs, leading to improved fitness in the swine host, likely contributing to transmission. IMPORTANCE Influenza A viruses cause respiratory disease in several species, including humans and pigs. The bidirectional transmission of FLUAV between humans and pigs plays a significant role in the generation of novel viral strains, greatly impacting viral epidemiology. However, little is known about the evolutionary processes that allow human FLUAV to become established in pigs. In this study, we generated reassortant viruses containing human seasonal HA and neuraminidase (NA) on different constellations of internal genes and tested their ability to replicate and transmit in pigs. We demonstrated that a virus containing a common internal gene constellation currently found in U.S. swine was able to transmit efficiently via the respiratory route. We identified a specific amino acid substitution that was fixed in the respiratory contact pigs that was associated with improved replication in primary swine tracheal epithelial cells, suggesting it was crucial for the transmissibility of the human virus in pigs.
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Affiliation(s)
- Jong-suk Mo
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | | | - Matias Cardenas Perez
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Troy C. Sutton
- Department of Veterinary and Biomedical Sciences, Penn State University, University Park, Pennsylvania, USA
| | - Brianna Cowan
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Lucas M. Ferreri
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Ginger Geiger
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Phillip C. Gauger
- Veterinary Diagnostic & Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Daniel R. Perez
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | | | - Daniela S. Rajao
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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Graaf A, Petric PP, Sehl-Ewert J, Henritzi D, Breithaupt A, King J, Pohlmann A, Deutskens F, Beer M, Schwemmle M, Harder T. Cold-passaged isolates and bat-swine influenza a chimeric viruses as modified live-attenuated vaccines against influenza a viruses in pigs. Vaccine 2022; 40:6255-6270. [PMID: 36137904 DOI: 10.1016/j.vaccine.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/02/2022] [Accepted: 09/04/2022] [Indexed: 10/14/2022]
Abstract
Swine influenza A virus (swIAV) infections in pig populations cause considerable morbidity and economic losses. Frequent reverse zoonotic incursions of human IAV boost reassortment opportunities with authentic porcine and avian-like IAV in swine herds potentially enhancing zoonotic and even pre-pandemic potential. Vaccination using adjuvanted inactivated full virus vaccines is frequently used in attempting control of swIAV infections. Accelerated antigenic drift of swIAV in large swine holdings and interference of maternal antibodies with vaccine in piglets can compromise these efforts. Potentially more efficacious modified live-attenuated vaccines (MLVs) bear the risk of reversion of MLV to virulence. Here we evaluated new MLV candidates based on cold-passaged swIAV or on reassortment-incompetent bat-IAV-swIAV chimeric viruses. Serial cold-passaging of various swIAV subtypes did not yield unambiguously temperature-sensitive mutants although safety studies in mice and pigs suggested some degree of attenuation. Chimeric bat-swIAV expressing the hemagglutinin and neuraminidase of an avian-like H1N1, in contrast, proved to be safe in mice and pigs, and a single nasal inoculation induced protective immunity against homologous challenge in pigs. Reassortant-incompetent chimeric bat-swIAV vaccines could aid in reducing the amount of swIAV circulating in pig populations, thereby increasing animal welfare, limiting economic losses and lowering the risk of zoonotic swIAV transmission.
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Affiliation(s)
- Annika Graaf
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany.
| | - Philipp P Petric
- Institute of Virology, Medical Center, University of Freiburg, 79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Julia Sehl-Ewert
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | - Dinah Henritzi
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | - Angele Breithaupt
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | - Jacqueline King
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | - Anne Pohlmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | | | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | - Martin Schwemmle
- Institute of Virology, Medical Center, University of Freiburg, 79104 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Timm Harder
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
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Changes in the Hemagglutinin and Internal Gene Segments Were Needed for Human Seasonal H3 Influenza A Virus to Efficiently Infect and Replicate in Swine. Pathogens 2022; 11:pathogens11090967. [PMID: 36145399 PMCID: PMC9501159 DOI: 10.3390/pathogens11090967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/19/2022] [Accepted: 08/20/2022] [Indexed: 11/16/2022] Open
Abstract
The current diversity of influenza A viruses (IAV) circulating in swine is largely a consequence of human-to-swine transmission events and consequent evolution in pigs. However, little is known about the requirements for human IAVs to transmit to and subsequently adapt in pigs. Novel human-like H3 viruses were detected in swine herds in the U.S. in 2012 and have continued to circulate and evolve in swine. We evaluated the contributions of gene segments on the ability of these viruses to infect pigs by using a series of in vitro models. For this purpose, reassortant viruses were generated by reverse genetics (rg) swapping the surface genes (hemagglutinin-HA and neuraminidase-NA) and internal gene segment backbones between a human-like H3N1 isolated from swine and a seasonal human H3N2 virus with common HA ancestry. Virus growth kinetics in porcine intestinal epithelial cells (SD-PJEC) and in ex-vivo porcine trachea explants were significantly reduced by replacing the swine-adapted HA with the human seasonal HA. Unlike the human HA, the swine-adapted HA demonstrated more abundant attachment to epithelial cells throughout the swine respiratory tract by virus histochemistry and increased entry into SD-PJEC swine cells. The human seasonal internal gene segments improved replication of the swine-adapted HA at 33 °C, but decreased replication at 40 °C. Although the HA was crucial for the infectivity in pigs and swine tissues, these results suggest that the adaptation of human seasonal H3 viruses to swine is multigenic and that the swine-adapted HA alone was not sufficient to confer the full phenotype of the wild-type swine-adapted virus.
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9
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Chauhan RP, Gordon ML. Review of genome sequencing technologies in molecular characterization of influenza A viruses in swine. J Vet Diagn Invest 2022; 34:177-189. [PMID: 35037523 PMCID: PMC8921814 DOI: 10.1177/10406387211068023] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The rapidly evolving antigenic diversity of influenza A virus (IAV) genomes in swine makes it imperative to detect emerging novel strains and track their circulation. We analyzed in our review the sequencing technologies used for subtyping and characterizing swine IAV genomes. Google Scholar, PubMed, and International Nucleotide Sequence Database Collaboration (INSDC) database searches identified 216 studies that have utilized Sanger, second-, and third-generation sequencing techniques to subtype and characterize swine IAV genomes up to 31 March 2021. Sanger dideoxy sequencing was by far the most widely used sequencing technique for generating either full-length (43.0%) or partial (31.0%) IAV genomes in swine globally; however, in the last decade, other sequencing platforms such as Illumina have emerged as serious competitors for the generation of whole-genome sequences of swine IAVs. Although partial HA and NA gene sequences were sufficient to determine swine IAV subtypes, whole-genome sequences were critical for determining reassortments and identifying unusual or less frequently occurring IAV subtypes. The combination of Sanger and second-generation sequencing technologies also greatly improved swine IAV characterization. In addition, the rapidly evolving third-generation sequencing platform, MinION, appears promising for on-site, real-time sequencing of complete swine IAV genomes. With a higher raw read accuracy, the use of the MinION could enhance the scalability of swine IAV testing in the field and strengthen the swine IAV disease outbreak response.
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Affiliation(s)
| | - Michelle L. Gordon
- Michelle L. Gordon, School of Laboratory Medicine and Medical Sciences, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, 719 Umbilo Rd, Durban 4001, South Africa.
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Kaplan BS, Anderson TK, Chang J, Santos J, Perez D, Lewis N, Vincent AL. Evolution and Antigenic Advancement of N2 Neuraminidase of Swine Influenza A Viruses Circulating in the United States following Two Separate Introductions from Human Seasonal Viruses. J Virol 2021; 95:e0063221. [PMID: 34379513 PMCID: PMC8475526 DOI: 10.1128/jvi.00632-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/15/2021] [Indexed: 12/15/2022] Open
Abstract
Two separate introductions of human seasonal N2 neuraminidase genes were sustained in U.S. swine since 1998 (N2-98) and 2002 (N2-02). Herein, we characterized the antigenic evolution of the N2 of swine influenza A virus (IAV) across 2 decades following each introduction. The N2-98 and N2-02 expanded in genetic diversity, with two statistically supported monophyletic clades within each lineage. To assess antigenic drift in swine N2 following the human-to-swine spillover events, we generated a panel of swine N2 antisera against representative N2 and quantified the antigenic distance between wild-type viruses using enzyme-linked lectin assay and antigenic cartography. The antigenic distance between swine and human N2 was smallest between human N2 circulating at the time of each introduction and the archetypal swine N2. However, sustained circulation and evolution in swine of the two N2 lineages resulted in significant antigenic drift, and the N2-98 and N2-02 swine N2 lineages were antigenically distinct. Although intralineage antigenic diversity was observed, the magnitude of antigenic drift did not consistently correlate with the observed genetic differences. These data represent the first quantification of the antigenic diversity of neuraminidase of IAV in swine and demonstrated significant antigenic drift from contemporary human seasonal strains as well as antigenic variation among N2 detected in swine. These data suggest that antigenic mismatch may occur between circulating swine IAV and vaccine strains. Consequently, consideration of the diversity of N2 in swine IAV for vaccine selection may likely result in more effective control and aid public health initiatives for pandemic preparedness. IMPORTANCE Antibodies inhibiting the neuraminidase (NA) of IAV reduce clinical disease, virus shedding, and transmission, particularly in the absence of neutralizing immunity against hemagglutinin. To understand antibody recognition of the genetically diverse NA in U.S. swine IAV, we characterized the antigenic diversity of N2 from swine and humans. N2 detected in swine IAV were derived from two distinct human-to-swine spillovers that persisted, are antigenically distinct, and underwent antigenic drift. These findings highlight the need for continued surveillance and vaccine development in swine with increased focus on the NA. Additionally, human seasonal N2 isolated after 2005 were poorly inhibited by representative swine N2 antisera, suggesting a lack of cross-reactive NA antibody-mediated immunity between contemporary swine and human N2. Bidirectional transmission between humans and swine represents a One Health challenge, and determining the correlates of immunity to emerging IAV strains is critical to mitigating zoonotic and reverse-zoonotic transmission.
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Affiliation(s)
- Bryan S. Kaplan
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
| | - Tavis K. Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
| | - Jennifer Chang
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
| | - Jefferson Santos
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Daniel Perez
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Nicola Lewis
- Department of Pathobiology and Population Sciences, The Royal Veterinary College, University of London, London, Hertfordshire, UK
| | - Amy L. Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
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11
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Multiple Gene Segments Are Associated with Enhanced Virulence of Clade 2.3.4.4 H5N8 Highly Pathogenic Avian Influenza Virus in Mallards. J Virol 2021; 95:e0095521. [PMID: 34232725 DOI: 10.1128/jvi.00955-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Highly pathogenic avian influenza (HPAI) viruses from the H5Nx Goose/Guangdong/96 lineage continue to cause outbreaks in domestic and wild bird populations. Two distinct genetic groups of H5N8 HPAI viruses, hemagglutinin (HA) clades 2.3.4.4A and 2.3.4.4B, caused intercontinental outbreaks in 2014 to 2015 and 2016 to 2017, respectively. Experimental infections using viruses from these outbreaks demonstrated a marked difference in virulence in mallards, with the H5N8 virus from 2014 causing mild clinical disease and the 2016 H5N8 virus causing high mortality. To assess which gene segments are associated with enhanced virulence of H5N8 HPAI viruses in mallards, we generated reassortant viruses with 2014 and 2016 viruses. For single-segment reassortants in the genetic backbone of the 2016 virus, pathogenesis experiments in mallards revealed that morbidity and mortality were reduced for all eight single-segment reassortants compared to the parental 2016 virus, with significant reductions in mortality observed with the polymerase basic protein 2 (PB2), nucleoprotein (NP), and matrix (M) reassortants. No differences in morbidity and mortality were observed with reassortants that either have the polymerase complex segments or the HA and neuraminidase (NA) segments of the 2016 virus in the genetic backbone of the 2014 virus. In vitro assays showed that the NP and polymerase acidic (PA) segments of the 2014 virus lowered polymerase activity when combined with the polymerase complex segments of the 2016 virus. Furthermore, the M segment of the 2016 H5N8 virus was linked to filamentous virion morphology. Phylogenetic analyses demonstrated that gene segments related to the more virulent 2016 H5N8 virus have persisted in the contemporary H5Nx HPAI gene pool until 2020. IMPORTANCE Outbreaks of H5Nx HPAI viruses from the goose/Guangdong/96 lineage continue to occur in many countries and have resulted in substantial impact on wild birds and poultry. Epidemiological evidence has shown that wild waterfowl play a major role in the spread of these viruses. While HPAI virus infection in gallinaceous species causes high mortality, a wide range of disease outcomes has been observed in waterfowl species. In this study, we examined which gene segments contribute to severe disease in mallards infected with H5N8 HPAI viruses. No virus gene was solely responsible for attenuating the high virulence of a 2016 H5N8 virus, but the PB2, NP, and M segments significantly reduced mortality. The findings herein advance our knowledge on the pathobiology of avian influenza viruses in waterfowl and have potential implications on the ecology and epidemiology of H5Nx HPAI in wild bird populations.
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Mutation E48K in PB1 Polymerase Subunit Improves Stability of a Candidate Live Attenuated Influenza B Virus Vaccine. Vaccines (Basel) 2021; 9:vaccines9070800. [PMID: 34358217 PMCID: PMC8310045 DOI: 10.3390/vaccines9070800] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 06/24/2021] [Accepted: 07/01/2021] [Indexed: 11/17/2022] Open
Abstract
Influenza B virus (IBV) is a major respiratory pathogen of humans, particularly in the elderly and children, and vaccines are the most effective way to control it. In previous work, incorporation of two mutations (E580G, S660A) along with the addition of an HA epitope tag in the PB1 segment of B/Brisbane/60/2008 (B/Bris) resulted in an attenuated strain that was safe and effective as a live attenuated vaccine. A third attempted mutation (K391E) in PB1 was not always stable. Interestingly, viruses that maintained the K391E mutation were associated with the mutation E48K. To explore the contribution of the E48K mutation to stability of the K391E mutation, a vaccine candidate was generated by inserting both mutations, along with attenuating mutations E580G and S660A, in PB1 of B/Bris (B/Bris PB1att 4M). Serial passages of the B/Bris PB1att 4M vaccine candidate in eggs and MDCK indicated high stability. In silico structural analysis revealed a potential interaction between amino acids at positions 48 and 391. In mice, B/Bris PB1att 4M was safe and provided complete protection against homologous challenge. These results confirm the compensatory effect of mutation E48K to stabilize the K391E mutation, resulting in a safer, yet still protective, IBV LAIV vaccine.
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13
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Development of a Novel Live Attenuated Influenza A Virus Vaccine Encoding the IgA-Inducing Protein. Vaccines (Basel) 2021; 9:vaccines9070703. [PMID: 34198994 PMCID: PMC8310050 DOI: 10.3390/vaccines9070703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/19/2021] [Accepted: 06/22/2021] [Indexed: 11/26/2022] Open
Abstract
Live attenuated influenza virus (LAIV) vaccines elicit a combination of systemic and mucosal immunity by mimicking a natural infection. To further enhance protective mucosal responses, we incorporated the gene encoding the IgA-inducing protein (IGIP) into the LAIV genomes of the cold-adapted A/Leningrad/134/17/57 (H2N2) strain (caLen) and the experimental attenuated backbone A/turkey/Ohio/313053/04 (H3N2) (OH/04att). Incorporation of IGIP into the caLen background led to a virus that grew poorly in prototypical substrates. In contrast, IGIP in the OH/04att background (IGIP-H1att) virus grew to titers comparable to the isogenic backbone H1att (H1N1) without IGIP. IGIP-H1att- and H1caLen-vaccinated mice were protected against lethal challenge with a homologous virus. The IGIP-H1att vaccine generated robust serum HAI responses in naïve mice against the homologous virus, equal or better than those obtained with the H1caLen vaccine. Analyses of IgG and IgA responses using a protein microarray revealed qualitative differences in humoral and mucosal responses between vaccine groups. Overall, serum and bronchoalveolar lavage samples from the IGIP-H1att group showed trends towards increased stimulation of IgG and IgA responses compared to H1caLen samples. In summary, the introduction of genes encoding immunomodulatory functions into a candidate LAIV can serve as natural adjuvants to improve overall vaccine safety and efficacy.
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Bat influenza vectored NS1-truncated live vaccine protects pigs against heterologous virus challenge. Vaccine 2021; 39:1943-1950. [PMID: 33715905 DOI: 10.1016/j.vaccine.2021.02.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/20/2021] [Accepted: 02/27/2021] [Indexed: 12/31/2022]
Abstract
Swine influenza is an important disease for the swine industry. Currently used whole inactivated virus (WIV) vaccines can induce vaccine-associated enhanced respiratory disease (VAERD) in pigs when the vaccine strains mismatch with the infected viruses. Live attenuated influenza virus vaccine (LAIV) is effective to protect pigs against homologous and heterologous swine influenza virus infections without inducing VAERD but has safety concerns due to potential reassortment with circulating viruses. Herein, we used a chimeric bat influenza Bat09:mH3mN2 virus, which contains both surface HA and NA gene open reading frames of the A/swine/Texas/4199-2/1998 (H3N2) and six internal genes from the novel bat H17N10 virus, to develop modified live-attenuated viruses (MLVs) as vaccine candidates which cannot reassort with canonical influenza A viruses by co-infection. Two attenuated MLV vaccine candidates including the virus that expresses a truncated NS1 (Bat09:mH3mN2-NS1-128, MLV1) or expresses both a truncated NS1 and the swine IL-18 (Bat09:mH3mN2-NS1-128-IL-18, MLV2) were generated and evaluated in pigs against a heterologous H3N2 virus using the WIV vaccine as a control. Compared to the WIV vaccine, both MLV vaccines were able to reduce lesions and virus replication in lungs and limit nasal virus shedding without VAERD, also induced significantly higher levels of mucosal IgA response in lungs and significantly increased numbers of antigen-specific IFN-γ secreting cells against the challenge virus. However, no significant difference was observed in efficacy between the MLV1 and MLV2. These results indicate that bat influenza vectored MLV vaccines can be used as a safe live vaccine to prevent swine influenza.
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15
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Youk SS, Leyson CM, Seibert BA, Jadhao S, Perez DR, Suarez DL, Pantin-Jackwood MJ. Mutations in PB1, NP, HA, and NA Contribute to Increased Virus Fitness of H5N2 Highly Pathogenic Avian Influenza Virus Clade 2.3.4.4 in Chickens. J Virol 2021; 95:JVI.01675-20. [PMID: 33268526 PMCID: PMC8092828 DOI: 10.1128/jvi.01675-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 11/19/2020] [Indexed: 12/26/2022] Open
Abstract
The H5N8 highly pathogenic avian influenza (HPAI) clade 2.3.4.4 virus spread to North America by wild birds and reassorted to generate the H5N2 HPAI virus that caused the poultry outbreak in the United States in 2015. In previous studies, we showed that H5N2 viruses isolated from poultry in the later stages of the outbreak had higher infectivity and transmissibility in chickens than the wild bird index H5N2 virus. Here, we determined the genetic changes that contributed to the difference in host virus fitness by analyzing sequence data from all of the viruses detected during the H5N2 outbreak, and studying the pathogenicity of reassortant viruses generated with the index wild bird virus and a chicken virus from later in the outbreak. Viruses with the wild bird virus backbone and either PB1, NP, or the entire polymerase complex of the chicken isolate, caused higher and earlier mortality in chickens, with three mutations (PB1 E180D, M317V, and NP I109T) identified to increase polymerase activity in chicken cells. The reassortant virus with the HA and NA from the chicken virus, where mutations in functionally known gene regions were acquired as the virus circulated in turkeys (HA S141P and NA S416G) and later in chickens (HA M66I, L322Q), showed faster virus growth, bigger plaque size and enhanced heat persistence in vitro, and increased pathogenicity and transmissibility in chickens. Collectively, these findings demonstrate an evolutionary pathway in which a HPAI virus from wild birds can accumulate genetic changes to increase fitness in poultry.IMPORTANCE H5Nx highly pathogenic avian influenza (HPAI) viruses of the A/goose/Guangdong/1/96 lineage continue to circulate widely affecting both poultry and wild birds. These viruses continue to change and reassort, which affects their fitness to different avian hosts. In this study, we defined mutations associated with increased virus fitness in chickens as the clade 2.3.4.4. H5N2 HPAI virus circulated in different avian species. We identified mutations in the PB1, NP, HA, and NA virus proteins that were highly conserved in the poultry isolates and contributed to the adaptation of this virus in chickens. This knowledge is important for understanding the epidemiology of H5Nx HPAI viruses and specifically the changes related to adaptation of these viruses in poultry.
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Affiliation(s)
- Sung-Su Youk
- Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia, USA
| | - Christina M Leyson
- Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia, USA
| | - Brittany A Seibert
- Department of Population Health, University of Georgia, Poultry Diagnostic and Research Center, Athens, Georgia, USA
| | - Samadhan Jadhao
- Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia, USA
- Department of Pediatrics, School of Medicine, Emory University and Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Daniel R Perez
- Department of Population Health, University of Georgia, Poultry Diagnostic and Research Center, Athens, Georgia, USA
| | - David L Suarez
- Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia, USA
| | - Mary J Pantin-Jackwood
- Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia, USA
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Abstract
Reverse genetics is the process of generating an RNA virus from a cDNA copy. Reverse genetics systems have truly transformed our ability to manipulate and study negative-strand RNA viruses. Plasmid-based reverse genetics approaches for influenza viruses provide a better understanding of virulence, transmission, mechanisms of antiviral resistance, and the development of alternative vaccines and vaccination strategies. Studying the molecular changes that allow influenza A viruses (IAVs) to transmit among animal species is important to better understand their animal health and public health risks. In this chapter, the cloning of cDNA copies of IAV's RNA segments into a reverse genetics plasmid vector, the experimental procedures for studying viral polymerase activity, and the successful generation of recombinant IAVs are described.
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17
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Seibert B, Angel M, Caceres CJ, Sutton T, Kumar A, Ferreri L, Cardenas-Garcia S, Geiger G, Rajao D, Perez DR. Development of a swine RNA polymerase I driven Influenza reverse genetics system for the rescue of type A and B Influenza viruses. J Virol Methods 2021; 288:114011. [PMID: 33152409 PMCID: PMC8103788 DOI: 10.1016/j.jviromet.2020.114011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 10/26/2020] [Accepted: 10/30/2020] [Indexed: 11/30/2022]
Abstract
Influenza viruses are among the most significant pathogens of humans and animals. Reverse genetics allows for the study of molecular attributes that modulate virus host range, virulence and transmission. The most common reverse genetics methods use bi-directional vectors containing a host RNA polymerase (pol) I promoter to produce virus-like RNAs and a host RNA pol II promoter to direct the synthesis of viral proteins. Given the species-dependency of the pol I promoter and virus-host interactions that influence replication of animal-origin influenza viruses in human-derived cells, we explored the potential of using the swine RNA pol I promoter (spol1) in a bi-directional vector for rescuing type A and B influenza viruses (IAV and IBV, respectively) in swine and human cells. The spol1-based bi-directional plasmid vector led to efficient rescue of IAVs of different origins (human, swine, and avian) as well as IBV in both swine- and human-origin tissue culture cells. In addition, virus rescue was successful using a recombinant bacmid containing all eight segments of a swine origin IAV. In conclusion, the spol1-based reverse genetics system is a new platform to study influenza viruses and produce swine influenza vaccines with increased transfection efficiency.
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Affiliation(s)
- Brittany Seibert
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States
| | - Matthew Angel
- Cellular Biology Section, Laboratory of Viral Diseases NIAID, NIH, Bethesda, MD, United States
| | - C Joaquin Caceres
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States
| | - Troy Sutton
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, United States
| | - Ayush Kumar
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States
| | - Lucas Ferreri
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States
| | - Stivalis Cardenas-Garcia
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States
| | - Ginger Geiger
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States
| | - Daniela Rajao
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States
| | - Daniel R Perez
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, GA, United States.
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18
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Mancera Gracia JC, Pearce DS, Masic A, Balasch M. Influenza A Virus in Swine: Epidemiology, Challenges and Vaccination Strategies. Front Vet Sci 2020; 7:647. [PMID: 33195504 PMCID: PMC7536279 DOI: 10.3389/fvets.2020.00647] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/11/2020] [Indexed: 01/01/2023] Open
Abstract
Influenza A viruses cause acute respiratory infections in swine that result in significant economic losses for global pig production. Currently, three different subtypes of influenza A viruses of swine (IAV-S) co-circulate worldwide: H1N1, H3N2, and H1N2. However, the origin, genetic background and antigenic properties of those IAV-S vary considerably from region to region. Pigs could also have a role in the adaptation of avian influenza A viruses to humans and other mammalian hosts, either as intermediate hosts in which avian influenza viruses may adapt to humans, or as a “mixing vessel” in which influenza viruses from various origins may reassort, generating novel progeny viruses capable of replicating and spreading among humans. These potential roles highlight the importance of controlling influenza A viruses in pigs. Vaccination is currently the main tool to control IAV-S. Vaccines containing whole inactivated virus (WIV) with adjuvant have been traditionally used to generate highly specific antibodies against hemagglutinin (HA), the main antigenic protein. WIV vaccines are safe and protect against antigenically identical or very similar strains in the absence of maternally derived antibodies (MDAs). Yet, their efficacy is reduced against heterologous strains, or in presence of MDAs. Moreover, vaccine-associated enhanced respiratory disease (VAERD) has been described in pigs vaccinated with WIV vaccines and challenged with heterologous strains in the US. This, together with the increasingly complex epidemiology of SIVs, illustrates the need to explore new vaccination technologies and strategies. Currently, there are two different non-inactivated vaccines commercialized for swine in the US: an RNA vector vaccine expressing the HA of a H3N2 cluster IV, and a bivalent modified live vaccine (MLV) containing H1N2 γ-clade and H3N2 cluster IV. In addition, recombinant-protein vaccines, DNA vector vaccines and alternative attenuation technologies are being explored, but none of these new technologies has yet reached the market. The aim of this article is to provide a thorough review of the current epidemiological scenario of IAV-S, the challenges faced in the control of IAV-S infection and the tools being explored to overcome those challenges.
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Affiliation(s)
| | - Douglas S Pearce
- Zoetis Inc., Veterinary Medicine Research and Development, Kalamazoo, MI, United States
| | - Aleksandar Masic
- Zoetis Inc., Veterinary Medicine Research and Development, Kalamazoo, MI, United States
| | - Monica Balasch
- Zoetis Manufacturing & Research Spain S.L. Ctra., Girona, Spain
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19
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Smith A, Rodriguez L, El Ghouayel M, Nogales A, Chamberlain JM, Sortino K, Reilly E, Feng C, Topham DJ, Martínez-Sobrido L, Dewhurst S. A Live Attenuated Influenza Vaccine Elicits Enhanced Heterologous Protection When the Internal Genes of the Vaccine Are Matched to Those of the Challenge Virus. J Virol 2020; 94:e01065-19. [PMID: 31748399 PMCID: PMC6997774 DOI: 10.1128/jvi.01065-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/08/2019] [Indexed: 12/22/2022] Open
Abstract
Influenza A virus (IAV) causes significant morbidity and mortality, despite the availability of viral vaccines. The efficacy of live attenuated influenza vaccines (LAIVs) has been especially poor in recent years. One potential reason is that the master donor virus (MDV), on which all LAIVs are based, contains either the internal genes of the 1960 A/Ann Arbor/6/60 or the 1957 A/Leningrad/17/57 H2N2 viruses (i.e., they diverge considerably from currently circulating strains). We previously showed that introduction of the temperature-sensitive (ts) residue signature of the AA/60 MDV into a 2009 pandemic A/California/04/09 H1N1 virus (Cal/09) results in only 10-fold in vivo attenuation in mice. We have previously shown that the ts residue signature of the Russian A/Leningrad/17/57 H2N2 LAIV (Len LAIV) more robustly attenuates the prototypical A/Puerto Rico/8/1934 (PR8) H1N1 virus. In this work, we therefore introduced the ts signature from Len LAIV into Cal/09. This new Cal/09 LAIV is ts in vitro, highly attenuated (att) in mice, and protects from a lethal homologous challenge. In addition, when our Cal/09 LAIV with PR8 hemagglutinin and neuraminidase was used to vaccinate mice, it provided enhanced protection against a wild-type Cal/09 challenge relative to a PR8 LAIV with the same attenuating mutations. These findings suggest it may be possible to improve the efficacy of LAIVs by better matching the sequence of the MDV to currently circulating strains.IMPORTANCE Seasonal influenza infection remains a major cause of disease and death, underscoring the need for improved vaccines. Among current influenza vaccines, the live attenuated influenza vaccine (LAIV) is unique in its ability to elicit T-cell immunity to the conserved internal proteins of the virus. Despite this, LAIV has shown limited efficacy in recent years. One possible reason is that the conserved, internal genes of all current LAIVs derive from virus strains that were isolated between 1957 and 1960 and that, as a result, do not resemble currently circulating influenza viruses. We have therefore developed and tested a new LAIV, based on a currently circulating pandemic strain of influenza. Our results show that this new LAIV elicits improved protective immunity compared to a more conventional LAIV.
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MESH Headings
- Animals
- Antibodies, Neutralizing
- Antibodies, Viral/immunology
- Dogs
- Female
- HEK293 Cells
- Humans
- Immunogenicity, Vaccine/immunology
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza A Virus, H2N2 Subtype/genetics
- Influenza A Virus, H2N2 Subtype/immunology
- Influenza A virus/genetics
- Influenza A virus/immunology
- Influenza Vaccines/genetics
- Influenza Vaccines/immunology
- Influenza, Human/genetics
- Influenza, Human/immunology
- Influenza, Human/virology
- Madin Darby Canine Kidney Cells
- Mice
- Mice, Inbred C57BL
- Vaccines, Attenuated/immunology
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Affiliation(s)
- Andrew Smith
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
- Medical Scientist Training Program, University of Rochester, Rochester, New York, USA
| | - Laura Rodriguez
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
| | - Maya El Ghouayel
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
| | - Aitor Nogales
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
| | - Jeffrey M Chamberlain
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
| | - Katherine Sortino
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
| | - Emma Reilly
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, New York, USA
| | - Changyong Feng
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, New York, USA
| | - David J Topham
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, New York, USA
| | - Luis Martínez-Sobrido
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
| | - Stephen Dewhurst
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
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20
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Abstract
Influenza A viruses (IAVs) of the Orthomyxoviridae virus family cause one of the most important respiratory diseases in pigs and humans. Repeated outbreaks and rapid spread of genetically and antigenically distinct IAVs represent a considerable challenge for animal production and public health. Bidirection transmission of IAV between pigs and people has altered the evolutionary dynamics of IAV, and a "One Health" approach is required to ameliorate morbidity and mortality in both hosts and improve control strategies. Although only subtypes of H1N1, H1N2, and H3N2 are endemic in swine around the world, considerable diversity can be found not only in the hemagglutinin (HA) and neuraminidase (NA) genes but in the remaining six genes as well. Human and swine IAVs have demonstrated a particular propensity for interspecies transmission, leading to regular and sometimes sustained incursions from man to pig and vice versa. The diversity of IAVs in swine remains a critical challenge in the diagnosis and control of this important pathogen for swine health and in turn contributes to a significant public health risk.
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Affiliation(s)
- Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA.
| | - Tavis K Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
| | - Kelly M Lager
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
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21
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Holzer B, Morgan SB, Martini V, Sharma R, Clark B, Chiu C, Salguero FJ, Tchilian E. Immunogenicity and Protective Efficacy of Seasonal Human Live Attenuated Cold-Adapted Influenza Virus Vaccine in Pigs. Front Immunol 2019; 10:2625. [PMID: 31787986 PMCID: PMC6856147 DOI: 10.3389/fimmu.2019.02625] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 10/22/2019] [Indexed: 01/31/2023] Open
Abstract
Influenza A virus infection is a global health threat to livestock and humans, causing substantial mortality and morbidity. As both pigs and humans are readily infected with influenza viruses of similar subtype, the pig is a robust and appropriate model for investigating swine and human disease. We evaluated the efficacy of the human cold-adapted 2017–2018 quadrivalent seasonal LAIV in pigs against H1N1pdm09 challenge. LAIV immunized animals showed significantly reduced viral load in nasal swabs. There was limited replication of the H1N1 component of the vaccine in the nose, a limited response to H1N1 in the lung lymph nodes and a low H1N1 serum neutralizing titer. In contrast there was better replication of the H3N2 component of the LAIV, accompanied by a stronger response to H3N2 in the tracheobronchial lymph nodes (TBLN). Our data demonstrates that a single administration of human quadrivalent LAIV shows limited replication in the nose and induces detectable responses to the H1N1 and H3N2 components. These data suggest that pigs may be a useful model for assessing LAIV against influenza A viruses.
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Affiliation(s)
- Barbara Holzer
- Enhanced Host Responses, The Pirbright Institute, Woking, United Kingdom
| | - Sophie B Morgan
- Enhanced Host Responses, The Pirbright Institute, Woking, United Kingdom
| | - Veronica Martini
- Enhanced Host Responses, The Pirbright Institute, Woking, United Kingdom
| | - Rajni Sharma
- Enhanced Host Responses, The Pirbright Institute, Woking, United Kingdom
| | - Becky Clark
- Enhanced Host Responses, The Pirbright Institute, Woking, United Kingdom
| | - Christopher Chiu
- Department of Infectious Disease, Hammersmith Campus Imperial College London, London, United Kingdom
| | | | - Elma Tchilian
- Enhanced Host Responses, The Pirbright Institute, Woking, United Kingdom
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22
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Holzer B, Martini V, Edmans M, Tchilian E. T and B Cell Immune Responses to Influenza Viruses in Pigs. Front Immunol 2019; 10:98. [PMID: 30804933 PMCID: PMC6371849 DOI: 10.3389/fimmu.2019.00098] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/14/2019] [Indexed: 01/31/2023] Open
Abstract
Influenza viruses are an ongoing threat to humans and are endemic in pigs, causing considerable economic losses to farmers. Pigs are also a source of new viruses potentially capable of initiating human pandemics. Many tools including monoclonal antibodies, recombinant cytokines and chemokines, gene probes, tetramers, and inbred pigs allow refined analysis of immune responses against influenza. Recent advances in understanding of the pig innate system indicate that it shares many features with that of humans, although there is a larger gamma delta component. The fine specificity and mechanisms of cross-protective T cell immunity have yet to be fully defined, although it is clear that the local immune response is important. The repertoire of pig antibody response to influenza has not been thoroughly explored. Here we review current understanding of adaptive immune responses against influenza in pigs and the use of the pig as a model to study human disease.
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Affiliation(s)
- Barbara Holzer
- Department of Mucosal Immunology, The Pirbright Institute (BBSRC), Pirbright, United Kingdom
| | - Veronica Martini
- Department of Mucosal Immunology, The Pirbright Institute (BBSRC), Pirbright, United Kingdom
| | - Matthew Edmans
- Department of Mucosal Immunology, The Pirbright Institute (BBSRC), Pirbright, United Kingdom
| | - Elma Tchilian
- Department of Mucosal Immunology, The Pirbright Institute (BBSRC), Pirbright, United Kingdom
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Lee YT, Kim KH, Ko EJ, Kim MC, Lee YN, Hwang HS, Lee Y, Jung YJ, Kim YJ, Santos J, Perez DR, Kang SM. Enhancing the cross protective efficacy of live attenuated influenza virus vaccine by supplemented vaccination with M2 ectodomain virus-like particles. Virology 2019; 529:111-121. [PMID: 30685658 DOI: 10.1016/j.virol.2019.01.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/12/2019] [Accepted: 01/14/2019] [Indexed: 10/27/2022]
Abstract
Current influenza vaccines including live attenuated influenza virus (LAIV) provide suboptimal protection against drift and potential pandemic strains. We hypothesized that supplementing LAIV with a highly conserved antigenic target M2 ectodomain (M2e) would confer cross-protection by inducing humoral and cellular immune responses to conserved antigenic targets. Intranasal vaccination with LAIV (A/Netherlands/602/09, H1N1) supplemented with tandem repeat M2e containing virus-like particles (M2e5x VLP) induced M2e- and virus-specific antibodies. Upon heterosubtypic virus challenge, M2e5x VLP-supplemented LAIV vaccination of mice induced significantly improved cross protection by preventing weight loss and lowering lung viral titers. Further mechanistic studies on heterosubtypic immunity suggest that T cell responses to M2e and nucleoprotein as well as systemic and mucosal antibodies to M2e and viruses might be contributing to cross protection. Therefore, this study demonstrates a novel vaccination strategy to improve the cross protective efficacy of LAIV by supplementing with a conserved M2e antigenic target.
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Affiliation(s)
- Young-Tae Lee
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Green Cross Cell Corp., Yongin-si, Gyeonggi-do 16924, Republic of Korea
| | - Ki-Hye Kim
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Eun-Ju Ko
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Min-Chul Kim
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Komipharm Co., Ltd., Siheung, Gyeonggi-do 15094, Republic of Korea
| | - Yu-Na Lee
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Animal and Plant Quarantine Agency, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Hye-Suk Hwang
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Department of Microbiology, Chonnam National University, Hwasun-gun, Jeonnam, Republic of Korea
| | - Youri Lee
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Yu-Jin Jung
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Yu Jin Kim
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Jefferson Santos
- Department of Population Health, University of Georgia, Athens, GA 30602, USA
| | - Daniel R Perez
- Department of Population Health, University of Georgia, Athens, GA 30602, USA
| | - Sang-Moo Kang
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA.
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Santos JJS, Abente EJ, Obadan AO, Thompson AJ, Ferreri L, Geiger G, Gonzalez-Reiche AS, Lewis NS, Burke DF, Rajão DS, Paulson JC, Vincent AL, Perez DR. Plasticity of Amino Acid Residue 145 Near the Receptor Binding Site of H3 Swine Influenza A Viruses and Its Impact on Receptor Binding and Antibody Recognition. J Virol 2019; 93:e01413-18. [PMID: 30355680 PMCID: PMC6321904 DOI: 10.1128/jvi.01413-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/13/2018] [Indexed: 11/20/2022] Open
Abstract
The hemagglutinin (HA), a glycoprotein on the surface of influenza A virus (IAV), initiates the virus life cycle by binding to terminal sialic acid (SA) residues on host cells. The HA gradually accumulates amino acid substitutions that allow IAV to escape immunity through a mechanism known as antigenic drift. We recently confirmed that a small set of amino acid residues are largely responsible for driving antigenic drift in swine-origin H3 IAV. All identified residues are located adjacent to the HA receptor binding site (RBS), suggesting that substitutions associated with antigenic drift may also influence receptor binding. Among those substitutions, residue 145 was shown to be a major determinant of antigenic evolution. To determine whether there are functional constraints to substitutions near the RBS and their impact on receptor binding and antigenic properties, we carried out site-directed mutagenesis experiments at the single-amino-acid level. We generated a panel of viruses carrying substitutions at residue 145 representing all 20 amino acids. Despite limited amino acid usage in nature, most substitutions at residue 145 were well tolerated without having a major impact on virus replication in vitro All substitution mutants retained receptor binding specificity, but the substitutions frequently led to decreased receptor binding. Glycan microarray analysis showed that substitutions at residue 145 modulate binding to a broad range of glycans. Furthermore, antigenic characterization identified specific substitutions at residue 145 that altered antibody recognition. This work provides a better understanding of the functional effects of amino acid substitutions near the RBS and the interplay between receptor binding and antigenic drift.IMPORTANCE The complex and continuous antigenic evolution of IAVs remains a major hurdle for vaccine selection and effective vaccination. On the hemagglutinin (HA) of the H3N2 IAVs, the amino acid substitution N 145 K causes significant antigenic changes. We show that amino acid 145 displays remarkable amino acid plasticity in vitro, tolerating multiple amino acid substitutions, many of which have not yet been observed in nature. Mutant viruses carrying substitutions at residue 145 showed no major impairment in virus replication in the presence of lower receptor binding avidity. However, their antigenic characterization confirmed the impact of the 145 K substitution in antibody immunodominance. We provide a better understanding of the functional effects of amino acid substitutions implicated in antigenic drift and its consequences for receptor binding and antigenicity. The mutation analyses presented in this report represent a significant data set to aid and test the ability of computational approaches to predict binding of glycans and in antigenic cartography analyses.
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Affiliation(s)
- Jefferson J S Santos
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
| | - Eugenio J Abente
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, USA
| | - Adebimpe O Obadan
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
| | - Andrew J Thompson
- Department of Molecular Medicine and Immunology & Microbiology, The Scripps Research Institute, La Jolla, California, USA
| | - Lucas Ferreri
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
| | - Ginger Geiger
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
| | - Ana S Gonzalez-Reiche
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Nicola S Lewis
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - David F Burke
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Daniela S Rajão
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
| | - James C Paulson
- Department of Molecular Medicine and Immunology & Microbiology, The Scripps Research Institute, La Jolla, California, USA
| | - Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, USA
| | - Daniel R Perez
- Department of Population Health, Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
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Comparison of Adjuvanted-Whole Inactivated Virus and Live-Attenuated Virus Vaccines against Challenge with Contemporary, Antigenically Distinct H3N2 Influenza A Viruses. J Virol 2018; 92:JVI.01323-18. [PMID: 30185589 DOI: 10.1128/jvi.01323-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 08/31/2018] [Indexed: 12/25/2022] Open
Abstract
Influenza A viruses in swine (IAV-S) circulating in the United States of America are phylogenetically and antigenically distinct. A human H3 hemagglutinin (HA) was introduced into the IAV-S gene pool in the late 1990s, sustained continued circulation, and evolved into five monophyletic genetic clades, H3 clades IV-A to -E, after 2009. Across these phylogenetic clades, distinct antigenic clusters were identified, with three clusters (cyan, red, and green antigenic cluster) among the most frequently detected antigenic phenotypes (Abente EJ, Santos J, Lewis NS, Gauger PC, Stratton J, et al. J Virol 90:8266-8280, 2016, https://doi.org/10.1128/JVI.01002-16). Although it was demonstrated that antigenic diversity of H3N2 IAV-S was associated with changes at a few amino acid positions in the head of the HA, the implications of this diversity for vaccine efficacy were not tested. Using antigenically representative H3N2 viruses, we compared whole inactivated virus (WIV) and live-attenuated influenza virus (LAIV) vaccines for protection against challenge with antigenically distinct H3N2 viruses in pigs. WIV provided partial protection against antigenically distinct viruses but did not prevent virus replication in the upper respiratory tract. In contrast, LAIV provided complete protection from disease and virus was not detected after challenge with antigenically distinct viruses.IMPORTANCE Due to the rapid evolution of the influenza A virus, vaccines require continuous strain updates. Additionally, the platform used to deliver the vaccine can have an impact on the breadth of protection. Currently, there are various vaccine platforms available to prevent influenza A virus infection in swine, and we experimentally tested two: adjuvanted-whole inactivated virus and live-attenuated virus. When challenged with an antigenically distinct virus, adjuvanted-whole inactivated virus provided partial protection, while live-attenuated virus provided effective protection. Additional strategies are required to broaden the protective properties of inactivated virus vaccines, given the dynamic antigenic landscape of cocirculating strains in North America, whereas live-attenuated vaccines may require less frequent strain updates, based on demonstrated cross-protection. Enhancing vaccine efficacy to control influenza infections in swine will help reduce the impact they have on swine production and reduce the risk of swine-to-human transmission.
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Alternative Strategy for a Quadrivalent Live Attenuated Influenza Virus Vaccine. J Virol 2018; 92:JVI.01025-18. [PMID: 30135124 PMCID: PMC6189493 DOI: 10.1128/jvi.01025-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/14/2018] [Indexed: 02/07/2023] Open
Abstract
Seasonal influenza viruses infect 1 billion people worldwide and are associated with ∼500,000 deaths annually. In addition, the never-ending emergence of zoonotic influenza viruses associated with lethal human infections and of pandemic concern calls for the development of better vaccines and/or vaccination strategies against influenza virus. Regardless of the strategy, novel influenza virus vaccines must aim at providing protection against both seasonal influenza A and B viruses. In this study, we tested an alternative quadrivalent live attenuated influenza virus vaccine (QIV) formulation whose individual components have been previously shown to provide protection. We demonstrate in proof-of principle studies in mice that the QIV provides effective protection against lethal challenge with either influenza A or B virus. Influenza virus infections continue to pose a major public health threat worldwide associated with seasonal epidemics and sporadic pandemics. Vaccination is considered the first line of defense against influenza. Live attenuated influenza virus vaccines (LAIVs) may provide superior responses compared to inactivated vaccines because the former can better elicit a combination of humoral and cellular responses by mimicking a natural infection. Unfortunately, during the 2013–2014, 2014–2015, and 2015–2016 seasons, concerns emerged about the effectiveness of the only LAIV approved in the United States that prevented the Advisory Committee on Immunization Practices (ACIP) from recommending its use. Such drawbacks open up the opportunity for alternative LAIV strategies that could overcome such concerns. Previously, we developed a combined strategy of temperature-sensitive mutations in the PB2 and PB1 segments and an epitope tag in the C terminus of PB1 that effectively attenuates influenza A viruses of avian and mammalian origin. More recently, we adopted a similar strategy for influenza B viruses. The resulting attenuated (att) influenza A and B viruses were safe, immunogenic, and protective against lethal influenza virus challenge in a variety of animal models. In this report, we provide evidence of the potential use of our att strategy in a quadrivalent LAIV (QIV) formulation carrying H3N2 and H1N1 influenza A virus subtype viruses and two antigenic lineages of influenza B viruses. In naive DBA/2J mice, two doses of the QIV elicited hemagglutination inhibition (HI) responses with HI titers of ≥40 and effectively protected against lethal challenge with prototypical pandemic H1N1 influenza A and influenza B virus strains. IMPORTANCE Seasonal influenza viruses infect 1 billion people worldwide and are associated with ∼500,000 deaths annually. In addition, the never-ending emergence of zoonotic influenza viruses associated with lethal human infections and of pandemic concern calls for the development of better vaccines and/or vaccination strategies against influenza virus. Regardless of the strategy, novel influenza virus vaccines must aim at providing protection against both seasonal influenza A and B viruses. In this study, we tested an alternative quadrivalent live attenuated influenza virus vaccine (QIV) formulation whose individual components have been previously shown to provide protection. We demonstrate in proof-of principle studies in mice that the QIV provides effective protection against lethal challenge with either influenza A or B virus.
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Hughes HR, Brockmeier SL, Loving CL. Bordetella bronchiseptica Colonization Limits Efficacy, but Not Immunogenicity, of Live-Attenuated Influenza Virus Vaccine and Enhances Pathogenesis After Influenza Challenge. Front Immunol 2018; 9:2255. [PMID: 30337924 PMCID: PMC6180198 DOI: 10.3389/fimmu.2018.02255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 09/11/2018] [Indexed: 11/13/2022] Open
Abstract
Intranasally administered live-attenuated influenza virus (LAIV) vaccines provide significant protection against heterologous influenza A virus (IAV) challenge. However, LAIV administration can modify the bacterial microbiota in the upper respiratory tract, including alterations in species that cause pneumonia. We sought to evaluate the effect of Bordetella bronchiseptica colonization on LAIV immunogenicity and efficacy in swine, and the impact of LAIV and IAV challenge on B. bronchiseptica colonization and disease. LAIV immunogenicity was not significantly impacted by B. bronchiseptica colonization, but protective efficacy against heterologous IAV challenge in the upper respiratory tract was impaired. Titers of IAV in the nose and trachea of pigs that received LAIV were significantly reduced when compared to non-vaccinated, challenged controls, regardless of B. bronchiseptica infection. Pneumonia scores were higher in pigs colonized with B. bronchiseptica and challenged with IAV, but this was regardless of LAIV vaccination status. While LAIV vaccination provided significant protection against heterologous IAV challenge, the protection was not sterilizing and IAV replicated in the respiratory tract of all LAIV vaccinated pig. The interaction between IAV, B. bronchiseptica, and host led to development of acute-type B. bronchiseptica lesions in the lung. Thus, the data presented do not negate the efficacy of LAIV vaccination, but instead indicate that controlling B. bronchiseptica colonization in swine could limit the negative interaction between IAV and Bordetella on swine health.
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Affiliation(s)
- Holly R Hughes
- Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Services, U.S. Department of Agriculture, Ames, IA, United States
| | - Susan L Brockmeier
- Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Services, U.S. Department of Agriculture, Ames, IA, United States
| | - Crystal L Loving
- Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Services, U.S. Department of Agriculture, Ames, IA, United States.,Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Services, U.S. Department of Agriculture, Ames, IA, United States
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Kaplan BS, Souza CK, Gauger PC, Stauft CB, Robert Coleman J, Mueller S, Vincent AL. Vaccination of pigs with a codon-pair bias de-optimized live attenuated influenza vaccine protects from homologous challenge. Vaccine 2018; 36:1101-1107. [PMID: 29366707 DOI: 10.1016/j.vaccine.2018.01.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/05/2018] [Accepted: 01/06/2018] [Indexed: 11/16/2022]
Abstract
Influenza A virus (IAV) in swine constitutes a major economic burden for producers as well as a potential threat to public health. Whole inactivated virus vaccines (WIV) are the predominant countermeasure employed to control IAV in swine herds in the United States despite the superior protection, and diminished adverse effects, induced by live attenuated influenza vaccines (LAIV). A major hurdle for the development of LAIV exists in achieving the proper level of attenuation while maintaining immunogenicity. Using Synthetic Attenuated Virus Engineering (SAVE) to introduce codon-pair bias de-optimization (CPBD) into the hemagglutinin (HA) and neuraminidase (NA) gene segments of pandemic H1N1 IAV, a novel LAIV was produced and evaluated for attenuation, immunogenicity, and efficacy in pigs. The CPBD LAIV induced inappreciable pathology following intranasal administration yet induced robust serum and mucosal antibody titers. CPBD LAIV vaccinated pigs challenged with wild-type virus showed protection from disease and virus detection, highlighted by the absence of detectable virus titers in the nasal passages and lungs. These results demonstrate the efficacy of a LAIV designed by SAVE codon de-optimization in pigs, providing support for the continued development of CPBD LAIV for use in swine.
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Affiliation(s)
- Bryan S Kaplan
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
| | - Carine K Souza
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
| | - Phillip C Gauger
- Dept. of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | | | | | | | - Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, 1920 Dayton Ave, Ames, IA 50010, USA.
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Rajão DS, Pérez DR. Universal Vaccines and Vaccine Platforms to Protect against Influenza Viruses in Humans and Agriculture. Front Microbiol 2018; 9:123. [PMID: 29467737 PMCID: PMC5808216 DOI: 10.3389/fmicb.2018.00123] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/18/2018] [Indexed: 01/22/2023] Open
Abstract
Influenza virus infections pose a significant threat to public health due to annual seasonal epidemics and occasional pandemics. Influenza is also associated with significant economic losses in animal production. The most effective way to prevent influenza infections is through vaccination. Current vaccine programs rely heavily on the vaccine's ability to stimulate neutralizing antibody responses to the hemagglutinin (HA) protein. One of the biggest challenges to an effective vaccination program lies on the fact that influenza viruses are ever-changing, leading to antigenic drift that results in escape from earlier immune responses. Efforts toward overcoming these challenges aim at improving the strength and/or breadth of the immune response. Novel vaccine technologies, the so-called universal vaccines, focus on stimulating better cross-protection against many or all influenza strains. However, vaccine platforms or manufacturing technologies being tested to improve vaccine efficacy are heterogeneous between different species and/or either tailored for epidemic or pandemic influenza. Here, we discuss current vaccines to protect humans and animals against influenza, highlighting challenges faced to effective and uniform novel vaccination strategies and approaches.
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Affiliation(s)
- Daniela S. Rajão
- Department of Population Health, University of Georgia, Athens, GA, United States
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Vincent AL, Perez DR, Rajao D, Anderson TK, Abente EJ, Walia RR, Lewis NS. Influenza A virus vaccines for swine. Vet Microbiol 2017; 206:35-44. [DOI: 10.1016/j.vetmic.2016.11.026] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/20/2016] [Accepted: 11/23/2016] [Indexed: 12/09/2022]
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Development of an Alternative Modified Live Influenza B Virus Vaccine. J Virol 2017; 91:JVI.00056-17. [PMID: 28381580 PMCID: PMC5446642 DOI: 10.1128/jvi.00056-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/31/2017] [Indexed: 12/27/2022] Open
Abstract
Influenza B virus (IBV) is considered a major human pathogen, responsible for seasonal epidemics of acute respiratory illness. Two antigenically distinct IBV hemagglutinin (HA) lineages cocirculate worldwide with little cross-reactivity. Live attenuated influenza virus (LAIV) vaccines have been shown to provide better cross-protective immune responses than inactivated vaccines by eliciting local mucosal immunity and systemic B cell- and T cell-mediated memory responses. We have shown previously that incorporation of temperature-sensitive (ts) mutations into the PB1 and PB2 subunits along with a modified HA epitope tag in the C terminus of PB1 resulted in influenza A viruses (IAV) that are safe and effective as modified live attenuated (att) virus vaccines (IAV att). We explored whether analogous mutations in the IBV polymerase subunits would result in a stable virus with an att phenotype. The PB1 subunit of the influenza B/Brisbane/60/2008 strain was used to incorporate ts mutations and a C-terminal HA tag. Such modifications resulted in a B/Bris att strain with ts characteristics in vitro and an att phenotype in vivo Vaccination studies in mice showed that a single dose of the B/Bris att candidate stimulated sterilizing immunity against lethal homologous challenge and complete protection against heterologous challenge. These studies show the potential of an alternative LAIV platform for the development of IBV vaccines.IMPORTANCE A number of issues with regard to the effectiveness of the LAIV vaccine licensed in the United States (FluMist) have arisen over the past three seasons (2013-2014, 2014-2015, and 2015-2016). While the reasons for the limited robustness of the vaccine-elicited immune response remain controversial, this problem highlights the critical importance of continued investment in LAIV development and creates an opportunity to improve current strategies so as to develop more efficacious vaccines. Our laboratory has developed an alternative strategy, the incorporation of 2 amino acid mutations and a modified HA tag at the C terminus of PB1, which is sufficient to attenuate the IBV. As a LAIV, this novel vaccine provides complete protection against IBV strains. The availability of attenuated IAV and IBV backbones based on contemporary strains offers alternative platforms for the development of LAIVs that may overcome current limitations.
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Tchilian E, Holzer B. Harnessing Local Immunity for an Effective Universal Swine Influenza Vaccine. Viruses 2017; 9:v9050098. [PMID: 28475122 PMCID: PMC5454411 DOI: 10.3390/v9050098] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 02/06/2023] Open
Abstract
Influenza A virus infections are a global health threat to humans and are endemic in pigs, contributing to decreased weight gain and suboptimal reproductive performance. Pigs are also a source of new viruses of mixed swine, avian, and human origin, potentially capable of initiating human pandemics. Current inactivated vaccines induce neutralising antibody against the immunising strain but rapid escape occurs through antigenic drift of the surface glycoproteins. However, it is known that prior infection provides a degree of cross-protective immunity mediated by cellular immune mechanisms directed at the more conserved internal viral proteins. Here we review new data that emphasises the importance of local immunity in cross-protection and the role of the recently defined tissue-resident memory T cells, as well as locally-produced, and sometimes cross-reactive, antibody. Optimal induction of local immunity may require aerosol delivery of live vaccines, but it remains unclear how long protective local immunity persists. Nevertheless, a universal vaccine might be extremely useful for disease prevention in the face of a pandemic. As a natural host for influenza A viruses, pigs are both a target for a universal vaccine and an excellent model for developing human influenza vaccines.
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Affiliation(s)
- Elma Tchilian
- The Pirbright Institute, Woking, Surrey GU24 0NF, UK.
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Olson ZF, Sandbulte MR, Souza CK, Perez DR, Vincent AL, Loving CL. Factors affecting induction of peripheral IFN-γ recall response to influenza A virus vaccination in pigs. Vet Immunol Immunopathol 2017; 185:57-65. [DOI: 10.1016/j.vetimm.2017.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/13/2017] [Accepted: 01/31/2017] [Indexed: 01/12/2023]
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35
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The Molecular Determinants of Antibody Recognition and Antigenic Drift in the H3 Hemagglutinin of Swine Influenza A Virus. J Virol 2016; 90:8266-80. [PMID: 27384658 DOI: 10.1128/jvi.01002-16] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/28/2016] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Influenza A virus (IAV) of the H3 subtype is an important respiratory pathogen that affects both humans and swine. Vaccination to induce neutralizing antibodies against the surface glycoprotein hemagglutinin (HA) is the primary method used to control disease. However, due to antigenic drift, vaccine strains must be periodically updated. Six of the 7 positions previously identified in human seasonal H3 (positions 145, 155, 156, 158, 159, 189, and 193) were also indicated in swine H3 antigenic evolution. To experimentally test the effect on virus antigenicity of these 7 positions, substitutions were introduced into the HA of an isogenic swine lineage virus. We tested the antigenic effect of these introduced substitutions by using hemagglutination inhibition (HI) data with monovalent swine antisera and antigenic cartography to evaluate the antigenic phenotype of the mutant viruses. Combinations of substitutions within the antigenic motif caused significant changes in antigenicity. One virus mutant that varied at only two positions relative to the wild type had a >4-fold reduction in HI titers compared to homologous antisera. Potential changes in pathogenesis and transmission of the double mutant were evaluated in pigs. Although the double mutant had virus shedding titers and transmissibility comparable to those of the wild type, it caused a significantly lower percentage of lung lesions. Elucidating the antigenic effects of specific amino acid substitutions at these sites in swine H3 IAV has important implications for understanding IAV evolution within pigs as well as for improved vaccine development and control strategies in swine. IMPORTANCE A key component of influenza virus evolution is antigenic drift mediated by the accumulation of amino acid substitutions in the hemagglutinin (HA) protein, resulting in escape from prior immunity generated by natural infection or vaccination. Understanding which amino acid positions of the HA contribute to the ability of the virus to avoid prior immunity is important for understanding antigenic evolution and informs vaccine efficacy predictions based on the genetic sequence data from currently circulating strains. Following our previous work characterizing antigenic phenotypes of contemporary wild-type swine H3 influenza viruses, we experimentally validated that substitutions at 6 amino acid positions in the HA protein have major effects on antigenicity. An improved understanding of the antigenic diversity of swine influenza will facilitate a rational approach for selecting more effective vaccine components to control the circulation of influenza in pigs and reduce the potential for zoonotic viruses to emerge.
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Tremblay N, Baril M, Chatel-Chaix L, Es-Saad S, Park AY, Koenekoop RK, Lamarre D. Spliceosome SNRNP200 Promotes Viral RNA Sensing and IRF3 Activation of Antiviral Response. PLoS Pathog 2016; 12:e1005772. [PMID: 27454487 PMCID: PMC4959778 DOI: 10.1371/journal.ppat.1005772] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 06/27/2016] [Indexed: 12/18/2022] Open
Abstract
Spliceosomal SNRNP200 is a Ski2-like RNA helicase that is associated with retinitis pigmentosa 33 (RP33). Here we found that SNRNP200 promotes viral RNA sensing and IRF3 activation through the ability of its amino-terminal Sec63 domain (Sec63-1) to bind RNA and to interact with TBK1. We show that SNRNP200 relocalizes into TBK1-containing cytoplasmic structures upon infection, in contrast to the RP33-associated S1087L mutant, which is also unable to rescue antiviral response of SNRNP200 knockdown cells. This functional rescue correlates with the Sec63-1-mediated binding of viral RNA. The hindered IFN-β production of knockdown cells was further confirmed in peripheral blood cells of RP33 patients bearing missense mutation in SNRNP200 upon infection with Sendai virus (SeV). This work identifies a novel immunoregulatory role of the spliceosomal SNRNP200 helicase as an RNA sensor and TBK1 adaptor for the activation of IRF3-mediated antiviral innate response. The innate immune system is the first line of defense against pathogens and relies on the recognition of molecular structures specific to pathogens by sensor receptors. These receptors activate a signaling cascade and induce a protective cellular innate immune response. In this study, we provide evidence for a role of the spliceosomal SNRNP200 RNA helicase in promoting antiviral response that is clearly distinguishable of the one in pre-mRNA splicing. The depletion of SNRNP200 in human cells resulted in a reduced interferon-β (IFNB1) production and increased susceptibility to viral infection. We showed that SNRNP200 positively regulates activation of the key transcription factor IRF3 via interaction with TANK kinase 1 (TBK1). Upon infection, SNRNP200 binds viral RNA and relocalizes into TBK1-containing cytoplasmic structures to promote IRF3 activation and IFNB1 production. Of clinical relevance, we observed a significantly hindered antiviral response of PBMCs from patients carrying a dominant SNRNP200 mutation associated with retina pigmentosa type 33 (RP33), an inherited degenerative eye disease. We showed that the RP33-associated S1087L SNRNP200 mutant has lost the ability to bind RNA and that its expression fails to rescue antiviral response in SNRNP200 silenced cells. Our study provides new insights into a role within the antiviral response for spliceosome SNRNP200 helicase as an RNA sensor and TBK1 adaptor in IRF3 signaling.
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Affiliation(s)
- Nicolas Tremblay
- Centre de Recherche du CHUM (CRCHUM), Montréal, Québec, Canada
- Faculté de Médecine, Université de Montréal, Montréal, Canada
| | - Martin Baril
- Centre de Recherche du CHUM (CRCHUM), Montréal, Québec, Canada
| | | | - Salwa Es-Saad
- Centre de Recherche du CHUM (CRCHUM), Montréal, Québec, Canada
| | - Alex Young Park
- Centre de Recherche du CHUM (CRCHUM), Montréal, Québec, Canada
- Faculté de Médecine, Université de Montréal, Montréal, Canada
| | - Robert K. Koenekoop
- Departments of Pediatric Surgery, Human Genetics and Ophthalmology, McGill University, Montréal, Canada
| | - Daniel Lamarre
- Centre de Recherche du CHUM (CRCHUM), Montréal, Québec, Canada
- Faculté de Médecine, Université de Montréal, Montréal, Canada
- * E-mail:
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Rajão DS, Chen H, Perez DR, Sandbulte MR, Gauger PC, Loving CL, Shanks GD, Vincent A. Vaccine-associated enhanced respiratory disease is influenced by haemagglutinin and neuraminidase in whole inactivated influenza virus vaccines. J Gen Virol 2016; 97:1489-1499. [DOI: 10.1099/jgv.0.000468] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Daniela S. Rajão
- Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA, USA
| | - Hongjun Chen
- Department of Veterinary Medicine, University of Maryland, College Park, and Virginia-Maryland Regional College of Veterinary Medicine, College Park, MD, USA
| | - Daniel R. Perez
- Department of Veterinary Medicine, University of Maryland, College Park, and Virginia-Maryland Regional College of Veterinary Medicine, College Park, MD, USA
| | - Matthew R. Sandbulte
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA
| | - Phillip C. Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Crystal L. Loving
- Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA, USA
| | | | - Amy Vincent
- Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA, USA
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Neuraminidase inhibiting antibody responses in pigs differ between influenza A virus N2 lineages and by vaccine type. Vaccine 2016; 34:3773-9. [PMID: 27325350 DOI: 10.1016/j.vaccine.2016.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 05/16/2016] [Accepted: 06/01/2016] [Indexed: 11/22/2022]
Abstract
The neuraminidase (NA) protein of influenza A viruses (IAV) has important functional roles in the viral replication cycle. Antibodies specific to NA can reduce viral replication and limit disease severity, but are not routinely measured. We analyzed NA inhibiting (NI) antibody titers in serum and respiratory specimens of pigs vaccinated with intramuscular whole-inactivated virus (WIV), intranasal live-attenuated influenza virus (LAIV), and intranasal wild type (WT) IAV. NI titers were also analyzed in sera from an investigation of piglet vaccination in the presence of passive maternally-derived antibodies. Test antigens contained genetically divergent swine-lineage NA genes homologous or heterologous to the vaccines with mismatched hemagglutinin genes (HA). Naïve piglets responded to WIV and LAIV vaccines and WT infection with strong homologous serum NI titers. Cross-reactivity to heterologous NAs depended on the degree of genetic divergence between the NA genes. Bronchoalveolar lavage specimens of LAIV and WT-immunized groups also had significant NI titers against the homologous antigen whereas the WIV group did not. Piglets of vaccinated sows received high levels of passive NI antibody, but their NI responses to homologous LAIV vaccination were impeded. These data demonstrate the utility of the enzyme-linked lectin assay for efficient NI antibody titration of serum as well as respiratory tract secretions. Swine IAV vaccines that induce robust NI responses are likely to provide broader protection against the diverse and rapidly evolving IAV strains that circulate in pig populations. Mucosal antibodies to NA may be one of the protective immune mechanisms induced by LAIV vaccines.
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Souza CK, Rajão DS, Loving CL, Gauger PC, Pérez DR, Vincent AL. Age at Vaccination and Timing of Infection Do Not Alter Vaccine-Associated Enhanced Respiratory Disease in Influenza A Virus-Infected Pigs. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2016; 23:470-482. [PMID: 27030585 PMCID: PMC4895012 DOI: 10.1128/cvi.00563-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 03/24/2016] [Indexed: 12/12/2022]
Abstract
Whole inactivated virus (WIV) vaccines are widely used in the swine industry to reduce clinical disease against homologous influenza A virus (IAV) infection. In pigs experimentally challenged with antigenically distinct heterologous IAV of the same hemagglutinin subtype, WIV vaccinates have been shown to develop vaccine-associated enhanced respiratory disease (VAERD). We evaluated the impact of vaccine valency, age at vaccination, and duration between vaccination and challenge on the development of VAERD using vaccine containing δ1-H1N2 and challenge with pandemic H1N1 (pH1N1) virus. Pigs were vaccinated with monovalent WIV MN08 (δ1-H1N2) and bivalent (δ1-H1N2-H3N2 or δ1-H1N2-pH1N1) vaccines and then were challenged with pH1N1 at 3 weeks postboost (wpb). Another group was vaccinated with the same monovalent WIV and challenged at 6 wpb to determine if the time postvaccination plays a role in the development of VAERD. In a follow-up study, the impact of age of first WIV vaccination (at 4 versus 9 weeks of age) with a boost 3 weeks later (at 7 versus 12 weeks of age) was evaluated. A monovalent live-attenuated influenza virus (LAIV) vaccine administered at 4 and 7 weeks of age was also included. All mismatched WIV groups had significantly higher lung lesions than the LAIV, bivalent MN08-CA09, and control groups. Age of first vaccination or length of time between booster dose and subsequent challenge did not alter the development of VAERD in WIV-vaccinated pigs. Importantly, the mismatched component of the bivalent MN08-CA09 WIV did not override the protective effect of the matched vaccine component.
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MESH Headings
- Age Factors
- Animals
- Antibodies, Viral/blood
- Follow-Up Studies
- Humans
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza A Virus, H1N1 Subtype/isolation & purification
- Influenza A Virus, H1N1 Subtype/physiology
- Influenza A Virus, H3N2 Subtype/immunology
- Influenza A Virus, H3N2 Subtype/isolation & purification
- Influenza A Virus, H3N2 Subtype/physiology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/adverse effects
- Influenza Vaccines/immunology
- Lung/pathology
- Lung/virology
- Orthomyxoviridae Infections/immunology
- Orthomyxoviridae Infections/veterinary
- Orthomyxoviridae Infections/virology
- Respiratory Tract Diseases/immunology
- Respiratory Tract Diseases/prevention & control
- Respiratory Tract Diseases/veterinary
- Respiratory Tract Diseases/virology
- Swine
- Swine Diseases/immunology
- Swine Diseases/prevention & control
- Swine Diseases/virology
- Time Factors
- Vaccination/adverse effects
- Vaccines, Attenuated/administration & dosage
- Vaccines, Attenuated/immunology
- Vaccines, Inactivated/administration & dosage
- Vaccines, Inactivated/adverse effects
- Vaccines, Inactivated/immunology
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Affiliation(s)
- Carine K Souza
- Virus and Prion Diseases Research Unit, USDA-ARS, Ames, Iowa, USA
- Laboratório de Virologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Daniela S Rajão
- Virus and Prion Diseases Research Unit, USDA-ARS, Ames, Iowa, USA
| | - Crystal L Loving
- Virus and Prion Diseases Research Unit, USDA-ARS, Ames, Iowa, USA
| | | | - Daniel R Pérez
- Poultry Diagnostic and Research Center, University of Georgia, Athens, Georgia, USA
| | - Amy L Vincent
- Virus and Prion Diseases Research Unit, USDA-ARS, Ames, Iowa, USA
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Morgan SB, Hemmink JD, Porter E, Harley R, Shelton H, Aramouni M, Everett HE, Brookes SM, Bailey M, Townsend AM, Charleston B, Tchilian E. Aerosol Delivery of a Candidate Universal Influenza Vaccine Reduces Viral Load in Pigs Challenged with Pandemic H1N1 Virus. THE JOURNAL OF IMMUNOLOGY 2016; 196:5014-23. [PMID: 27183611 PMCID: PMC4891568 DOI: 10.4049/jimmunol.1502632] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/11/2016] [Indexed: 11/19/2022]
Abstract
Influenza A viruses are a major health threat to livestock and humans, causing considerable mortality, morbidity, and economic loss. Current inactivated influenza vaccines are strain specific and new vaccines need to be produced at frequent intervals to combat newly arising influenza virus strains, so that a universal vaccine is highly desirable. We show that pandemic H1N1 influenza virus in which the hemagglutinin signal sequence has been suppressed (S-FLU), when administered to pigs by aerosol can induce CD4 and CD8 T cell immune responses in blood, bronchoalveolar lavage (BAL), and tracheobronchial lymph nodes. Neutralizing Ab was not produced. Detection of a BAL response correlated with a reduction in viral titer in nasal swabs and lungs, following challenge with H1N1 pandemic virus. Intratracheal immunization with a higher dose of a heterologous H5N1 S-FLU vaccine induced weaker BAL and stronger tracheobronchial lymph node responses and a lesser reduction in viral titer. We conclude that local cellular immune responses are important for protection against influenza A virus infection, that these can be most efficiently induced by aerosol immunization targeting the lower respiratory tract, and that S-FLU is a promising universal influenza vaccine candidate.
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Affiliation(s)
| | | | - Emily Porter
- School of Veterinary Sciences, University of Bristol, Bristol BS40 5DU, United Kingdom
| | - Ross Harley
- School of Veterinary Sciences, University of Bristol, Bristol BS40 5DU, United Kingdom
| | - Holly Shelton
- The Pirbright Institute, Surrey GU24 0NF, United Kingdom
| | - Mario Aramouni
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Helen E Everett
- Virology Department, Animal and Plant Health Agency, Weybridge, Surrey KT15 3NB, United Kingdom; and
| | - Sharon M Brookes
- Virology Department, Animal and Plant Health Agency, Weybridge, Surrey KT15 3NB, United Kingdom; and
| | - Michael Bailey
- School of Veterinary Sciences, University of Bristol, Bristol BS40 5DU, United Kingdom
| | - Alain M Townsend
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | | | - Elma Tchilian
- The Pirbright Institute, Surrey GU24 0NF, United Kingdom;
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41
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Halasa NB, Savani BN, Asokan I, Kassim A, Simons R, Summers C, Bourgeois J, Clifton C, Vaughan LA, Lucid C, Wang L, Fonnesbeck C, Jagasia M. Randomized Double-Blind Study of the Safety and Immunogenicity of Standard-Dose Trivalent Inactivated Influenza Vaccine versus High-Dose Trivalent Inactivated Influenza Vaccine in Adult Hematopoietic Stem Cell Transplantation Patients. Biol Blood Marrow Transplant 2016; 22:528-35. [DOI: 10.1016/j.bbmt.2015.12.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 12/02/2015] [Indexed: 01/04/2023]
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Codon Deletions in the Influenza A Virus PA Gene Generate Temperature-Sensitive Viruses. J Virol 2016; 90:3684-93. [PMID: 26792748 DOI: 10.1128/jvi.03101-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/14/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The influenza virus RNA-dependent RNA polymerase, which is composed of three subunits, PB1, PB2, and PA, catalyzes genome replication and transcription within the cell nucleus. The PA linker (residues 197 to 256) can be altered by nucleotide substitutions to engineer temperature-sensitive (ts), attenuated mutants that display a defect in the transport of the PA-PB1 complex to the nucleus at a restrictive temperature. In this study, we investigated the ability of the PA linker to tolerate deletion mutations for further in vitro and in vivo characterization. Four viable mutants with single-codon deletions were generated; all of them exhibited a ts phenotype that was associated with the reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using fluorescently tagged PB1, we observed that the deletion mutants did not efficiently recruit PB1 to reach the nucleus at a restrictive temperature (39.5°C). Mouse infections showed that the four mutants were attenuated and induced antibodies that were able to protect mice from challenge with a lethal homologous wild-type virus. Serial in vitro passages of two deletion mutants at 39.5°C and 37°C did not allow the restoration of a wild-type phenotype among virus progeny. Thus, our results identify codons that can be deleted in the PA gene to engineer genetically stable ts mutants that could be used to design novel attenuated vaccines. IMPORTANCE In order to generate genetically stable live influenza A virus vaccines, we constructed viruses with single-codon deletions in a discrete domain of the RNA polymerase PA gene. The four rescued viruses exhibited a temperature-sensitive phenotype that we found was associated with a defect in the transport of the PA-PB1 dimer to the nucleus, where viral replication occurs. These ts deletion mutants were shown to be attenuated and to be able to produce antibodies in mice and to protect them from a lethal challenge. Assays to select revertants that were able to grow efficiently at a restrictive temperature failed, showing that these deletion mutants are genetically more stable than conventional substitution mutants. These results are of interest for the design of genetically stable live influenza virus vaccines.
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43
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Oral Fluids as a Live-Animal Sample Source for Evaluating Cross-Reactivity and Cross-Protection following Intranasal Influenza A Virus Vaccination in Pigs. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:1109-20. [PMID: 26291090 DOI: 10.1128/cvi.00358-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/13/2015] [Indexed: 12/13/2022]
Abstract
In North American swine, there are numerous antigenically distinct H1 influenza A virus (IAV) variants currently circulating, making vaccine development difficult due to the inability to formulate a vaccine that provides broad cross-protection. Experimentally, live-attenuated influenza virus (LAIV) vaccines demonstrate increased cross-protection compared to inactivated vaccines. However, there is no standardized assay to predict cross-protection following LAIV vaccination. Hemagglutination-inhibiting (HI) antibody in serum is the gold standard correlate of protection following IAV vaccination. LAIV vaccination does not induce a robust serum HI antibody titer; however, a local mucosal antibody response is elicited. Thus, a live-animal sample source that could be used to evaluate LAIV immunogenicity and cross-protection is needed. Here, we evaluated the use of oral fluids (OF) and nasal wash (NW) collected after IAV inoculation as a live-animal sample source in an enzyme-linked immunosorbent assay (ELISA) to predict cross-protection in comparison to traditional serology. Both live-virus exposure and LAIV vaccination provided heterologous protection, though protection was greatest against more closely phylogenetically related viruses. IAV-specific IgA was detected in NW and OF samples and was cross-reactive to representative IAV from each H1 cluster. Endpoint titers of cross-reactive IgA in OF from pigs exposed to live virus was associated with heterologous protection. While LAIV vaccination provided significant protection, LAIV immunogenicity was reduced compared to live-virus exposure. These data suggest that OF from pigs inoculated with wild-type IAV, with surface genes that match the LAIV seed strain, could be used in an ELISA to assess cross-protection and the antigenic relatedness of circulating and emerging IAV in swine.
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44
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Feng C, Tan M, Sun W, Shi Y, Xing Z. Attenuation of the influenza virus by microRNA response element in vivo and protective efficacy against 2009 pandemic H1N1 virus in mice. Int J Infect Dis 2015; 38:146-52. [PMID: 26163223 DOI: 10.1016/j.ijid.2015.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/29/2015] [Accepted: 07/02/2015] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The 2009 influenza pandemics underscored the need for effective vaccines to block the spread of influenza virus infection. Most live attenuated vaccines utilize cold-adapted, temperature-sensitive virus. An alternative to live attenuated virus is presented here, based on microRNA-induced gene silencing. METHODS In this study, miR-let-7b target sequences were inserted into the H1N1 genome to engineer a recombinant virus - miRT-H1N1. Female BALB/c mice were vaccinated intranasally with the miRT-H1N1 and challenged with a lethal dose of homologous virus. RESULTS This miRT-H1N1 virus was attenuated in mice, while it exhibited wild-type characteristics in chicken embryos. Mice vaccinated intranasally with the miRT-H1N1 responded with robust immunity that protected the vaccinated mice from a lethal challenge with the wild-type 2009 pandemic H1N1 virus. CONCLUSIONS These results indicate that the influenza virus containing microRNA response elements (MREs) is attenuated in vivo and can be used to design a live attenuated vaccine.
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Affiliation(s)
- Chunlai Feng
- Department of Respiratory and Critical Care Medicine, Jinling Hospital affiliated to Southern Medical University, Nanjing, China
| | - Mingming Tan
- Department of Respiratory and Critical Care Medicine, Jinling Hospital affiliated to Southern Medical University, Nanjing, China
| | - Wenkui Sun
- Department of Respiratory and Critical Care Medicine, Jinling Hospital affiliated to Southern Medical University, Nanjing, China
| | - Yi Shi
- Department of Respiratory and Critical Care Medicine, Jinling Hospital affiliated to Southern Medical University, Nanjing, China.
| | - Zheng Xing
- The Key Laboratory of Pharmaceutical Biotechnology and Medical School, Nanjing University, Nanjing, China; Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, University of Minnesota at Twin Cities, Saint Paul, Minnesota, USA.
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45
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Temperature-Sensitive Mutants in the Influenza A Virus RNA Polymerase: Alterations in the PA Linker Reduce Nuclear Targeting of the PB1-PA Dimer and Result in Viral Attenuation. J Virol 2015; 89:6376-90. [PMID: 25855727 DOI: 10.1128/jvi.00589-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 03/30/2015] [Indexed: 01/08/2023] Open
Abstract
UNLABELLED The influenza virus RNA-dependent RNA polymerase catalyzes genome replication and transcription within the cell nucleus. Efficient nuclear import and assembly of the polymerase subunits PB1, PB2, and PA are critical steps in the virus life cycle. We investigated the structure and function of the PA linker (residues 197 to 256), located between its N-terminal endonuclease domain and its C-terminal structured domain that binds PB1, the polymerase core. Circular dichroism experiments revealed that the PA linker by itself is structurally disordered. A large series of PA linker mutants exhibited a temperature-sensitive (ts) phenotype (reduced viral growth at 39.5°C versus 37°C/33°C), suggesting an alteration of folding kinetic parameters. The ts phenotype was associated with a reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using a fluorescent-tagged PB1, we observed that ts and lethal PA mutants did not efficiently recruit PB1 to reach the nucleus at 39.5°C. A protein complementation assay using PA mutants, PB1, and β-importin IPO5 tagged with fragments of the Gaussia princeps luciferase showed that increasing the temperature negatively modulated the PA-PB1 and the PA-PB1-IPO5 interactions or complex stability. The selection of revertant viruses allowed the identification of different types of compensatory mutations located in one or the other of the three polymerase subunits. Two ts mutants were shown to be attenuated and able to induce antibodies in mice. Taken together, our results identify a PA domain critical for PB1-PA nuclear import and that is a "hot spot" to engineer ts mutants that could be used to design novel attenuated vaccines. IMPORTANCE By targeting a discrete domain of the PA polymerase subunit of influenza virus, we were able to identify a series of 9 amino acid positions that are appropriate to engineer temperature-sensitive (ts) mutants. This is the first time that a large number of ts mutations were engineered in such a short domain, demonstrating that rational design of ts mutants can be achieved. We were able to associate this phenotype with a defect of transport of the PA-PB1 complex into the nucleus. Reversion substitutions restored the ability of the complex to move to the nucleus. Two of these ts mutants were shown to be attenuated and able to produce antibodies in mice. These results are of high interest for the design of novel attenuated vaccines and to develop new antiviral drugs.
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46
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Rahn J, Hoffmann D, Harder TC, Beer M. Vaccines against influenza A viruses in poultry and swine: Status and future developments. Vaccine 2015; 33:2414-24. [PMID: 25835575 DOI: 10.1016/j.vaccine.2015.03.052] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/01/2015] [Accepted: 03/18/2015] [Indexed: 12/29/2022]
Abstract
Influenza A viruses are important pathogens with a very broad host spectrum including domestic poultry and swine. For preventing clinical disease and controlling the spread, vaccination is one of the most efficient tools. Classical influenza vaccines for domestic poultry and swine are conventional inactivated preparations. However, a very broad range of novel vaccine types ranging from (i) nucleic acid-based vaccines, (ii) replicon particles, (iii) subunits and virus-like particles, (iv) vectored vaccines, or (v) live-attenuated vaccines has been described, and some of them are now also used in the field. The different novel approaches for vaccines against avian and swine influenza virus infections are reviewed, and additional features like universal vaccines, novel application approaches and the "differentiating infected from vaccinated animals" (DIVA)-strategy are summarized.
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Affiliation(s)
- J Rahn
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald-Insel Riems, Germany
| | - D Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald-Insel Riems, Germany
| | - T C Harder
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald-Insel Riems, Germany
| | - M Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald-Insel Riems, Germany.
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47
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Finch C, Li W, Perez DR. Design of alternative live attenuated influenza virus vaccines. Curr Top Microbiol Immunol 2015; 386:205-35. [PMID: 25005928 DOI: 10.1007/82_2014_404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Each year due to the ever-evolving nature of influenza, new influenza vaccines must be produced to provide protection against the influenza viruses in circulation. Currently, there are two mainstream strategies to generate seasonal influenza vaccines: inactivated and live-attenuated. Inactivated vaccines are non-replicating forms of whole influenza virus, while live-attenuated vaccines are viruses modified to be replication impaired. Although it is widely believed that by inducing both mucosal and humoral immune responses the live-attenuated vaccine provides better protection than that of the inactivated vaccine, there are large populations of individuals who cannot safely receive the LAIV vaccine. Thus, safer LAIV vaccines are needed to provide adequate protection to these populations. Improvement is also needed in the area of vaccine production. Current strategies relying on traditional tissue culture-based and egg-based methods are slow and delay production time. This chapter describes experimental vaccine generation and production strategies that address the deficiencies in current methods for potential human and agricultural use.
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Affiliation(s)
- Courtney Finch
- Department of Veterinary Medicine, College Park and Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD, USA
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48
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Sandbulte MR, Spickler AR, Zaabel PK, Roth JA. Optimal Use of Vaccines for Control of Influenza A Virus in Swine. Vaccines (Basel) 2015; 3:22-73. [PMID: 26344946 PMCID: PMC4494241 DOI: 10.3390/vaccines3010022] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/09/2015] [Accepted: 01/19/2015] [Indexed: 12/29/2022] Open
Abstract
Influenza A virus in swine (IAV-S) is one of the most important infectious disease agents of swine in North America. In addition to the economic burden of IAV-S to the swine industry, the zoonotic potential of IAV-S sometimes leads to serious public health concerns. Adjuvanted, inactivated vaccines have been licensed in the United States for over 20 years, and there is also widespread usage of autogenous/custom IAV-S vaccines. Vaccination induces neutralizing antibodies and protection against infection with very similar strains. However, IAV-S strains are so diverse and prone to mutation that these vaccines often have disappointing efficacy in the field. This scientific review was developed to help veterinarians and others to identify the best available IAV-S vaccine for a particular infected herd. We describe key principles of IAV-S structure and replication, protective immunity, currently available vaccines, and vaccine technologies that show promise for the future. We discuss strategies to optimize the use of available IAV-S vaccines, based on information gathered from modern diagnostics and surveillance programs. Improvements in IAV-S immunization strategies, in both the short term and long term, will benefit swine health and productivity and potentially reduce risks to public health.
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Affiliation(s)
- Matthew R Sandbulte
- Center for Food Security and Public Health, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
| | - Anna R Spickler
- Center for Food Security and Public Health, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
| | - Pamela K Zaabel
- Center for Food Security and Public Health, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
| | - James A Roth
- Center for Food Security and Public Health, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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Protection of pigs against pandemic swine origin H1N1 influenza A virus infection by hemagglutinin- or neuraminidase-expressing attenuated pseudorabies virus recombinants. Virus Res 2015; 199:20-30. [PMID: 25599604 DOI: 10.1016/j.virusres.2015.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/18/2014] [Accepted: 01/10/2015] [Indexed: 11/20/2022]
Abstract
Influenza is an important respiratory disease of pigs, and may lead to novel human pathogens like the 2009 pandemic H1N1 swine-origin influenza virus (SoIV). Therefore, improved influenza vaccines for pigs are required. Recently, we demonstrated that single intranasal immunization with a hemagglutinin (HA)-expressing pseudorabies virus recombinant of vaccine strain Bartha (PrV-Ba) protected pigs from H1N1 SoIV challenge (Klingbeil et al., 2014). Now we investigated enhancement of efficacy by prime-boost vaccination and/or intramuscular administration. Furthermore, a novel PrV-Ba recombinant expressing codon-optimized N1 neuraminidase (NA) was included. In vitro replication of this virus was only slightly affected compared to parental virus. Unlike HA, the abundantly expressed NA was efficiently incorporated into PrV particles. Immunization of pigs with the two PrV recombinants, either singly or in combination, induced B cell proliferation and the expected SoIV-specific antibodies, whose titers increased substantially after boost vaccination. After immunization of animals with either PrV recombinant H1N1 SoIV challenge virus replication was significantly reduced compared to PrV-Ba vaccinated or naïve controls. Protective efficacy of HA-expressing PrV was higher than of NA-expressing PrV, and not significantly enhanced by combination. Despite higher serum antibody titers obtained after intramuscular immunization, transmission of challenge virus to naïve contact animals was only prevented after intranasal prime-boost vaccination with HA-expressing PrV-Ba.
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Nelson MI, Vincent AL. Reverse zoonosis of influenza to swine: new perspectives on the human-animal interface. Trends Microbiol 2015; 23:142-53. [PMID: 25564096 DOI: 10.1016/j.tim.2014.12.002] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 01/09/2023]
Abstract
The origins of the 2009 influenza A (H1N1) pandemic in swine are unknown, highlighting gaps in our understanding of influenza A virus (IAV) ecology and evolution. We review how recently strengthened influenza virus surveillance in pigs has revealed that influenza virus transmission from humans to swine is far more frequent than swine-to-human zoonosis, and is central in seeding swine globally with new viral diversity. The scale of global human-to-swine transmission represents the largest 'reverse zoonosis' of a pathogen documented to date. Overcoming the bias towards perceiving swine as sources of human viruses, rather than recipients, is key to understanding how the bidirectional nature of the human-animal interface produces influenza threats to both hosts.
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Affiliation(s)
- Martha I Nelson
- Fogarty International Center, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, US Department of Agriculture (USDA) Agricultural Research Service (ARS), Ames, IA 50010, USA
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