- aDepartment of Microbiology and Immunology, University of Rochester, Rochester, Brand-new York, USA
- bDavid Smith Focus for Immunology and Vaccine Biology, University of Rochester, Rochester, Brand-new York, USA
ABSTRACT
Influenza viral infections represent a significant public good health problem, along with influenza virus causing a contagious respiratory ailment which is many properly avoided through vaccination. Segments 7 (M) and 8 (NS) of the influenza virus genome encode mRNA transcripts that are alternatively spliced to express two various viral proteins. This study describes the generation, making use of reverse genetics, of 3 various recombinant influenza A/Puerto Rico/8/1934 (PR8) H1N1 viruses containing M or NS viral segments individually or modified M or NS viral segments combined in which the overlapping open going through frames of matrix 1 (M1)/M2 for the modified M segment and the open going through frames of nonstructural healthy protein 1 (NS1)/nuclear export healthy protein (NEP) for the modified NS segment were split by making use of the porcine teschovirus 1 (PTV-1) 2A autoproteolytic cleavage site. Viruses along with an M split segment were impaired in replication at nonpermissive higher temperatures, whereas higher viral titers could be obtained at permissive reduced temperatures (33°C). Furthermore, viruses containing the M split segment were highly attenuated in vivo, while they retained their immunogenicity and given protection versus a lethal challenge along with wild-type PR8. These outcomes indicate that influenza viruses can easily be properly attenuated by the rearrangement of spliced segments and that such attenuated viruses represent a superb option as safe, immunogenic, and protective live-attenuated vaccines. Moreover, this is the initial time in which an influenza virus containing a restructured M segment has actually been described. Reorganization of the M segment to encode M1 and M2 from two separate, nonoverlapping, independent open going through frames represents a practical device to independently study mutations in the M1 and M2 viral proteins free of affecting the various other viral M product.
IMPORTANCE Vaccination represents our finest therapeutic option versus influenza viral infections. However, the efficacy of current influenza vaccines is suboptimal, and novel approaches are crucial for the prevention of ailment caused by this vital human respiratory pathogen. In this work, we describe a novel approach to yield safer and much more efficient live-attenuated influenza virus vaccines (LAIVs) based on recombinant viruses whose genomes encode nonoverlapping and independent M1/M2 (split M segment [Ms]) or the 2 M1/M2 and NS1/NEP (Ms and split NS segment [NSs]) open going through frames. Viruses containing a modified M segment were highly attenuated in mice yet were able to confer, upon a solitary intranasal immunization, finish protection versus a lethal homologous challenge along with wild-type virus. Notably, the protection efficacy conferred by our viruses along with split M segments was much better compared to that conferred by the most recent temperature-sensitive LAIV. Altogether, these outcomes open a Brand-new avenue for the improvement of safer and much more protective LAIVs on the basis of the reorganization of spliced viral RNA segments in the genome.
FOOTNOTES
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- Received 29 February 2016.
- Accepted 24 April 2016.
- Accepted manuscript posted online 27 April 2016.
- Address correspondence to Luis Martínez-Sobrido, luis_martinez{at}urmc.rochester.edu.
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A.N. and M.L.D. contributed equally as to this article.
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Citation Nogales A, DeDiego ML, Topham DJ, Martínez-Sobrido L. 2016. Rearrangement of influenza virus spliced segments for the improvement of live-attenuated vaccines. J Virol 90:6291–6302. doi:10.1128/JVI.00410-16.
- Copyright © 2016, American Society for Microbiology. every one of Rights Reserved.
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