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J Virol. 2014 Jun 25. pii: JVI.01565-14. [Epub ahead of print]
Influenza A virus attenuation by codon deoptimization of the NS gene for vaccine development.
Nogales A1, Baker SF1, Ortiz-Ria?o E1, Dewhurst S1, Topham DJ2, Mart?nez-Sobrido L3.
Author information
Abstract
Influenza virus infection represents a serious public health problem that causes contagious respiratory disease, which is most effectively prevented through vaccination to reduce transmission and future infection. The non-structural (NS) gene of influenza A virus encodes an mRNA transcript that is alternatively spliced to express two viral proteins, the non-structural protein 1 (NS1) and the nuclear export protein (NEP). The importance of the NS gene of influenza A for viral replication and virulence has been well described and represents an attractive target to generate live attenuated influenza viruses with vaccine potential. Considering that most amino acids can be synthesized from several synonymous codons, this study employs the use of misrepresented mammalian codons (codon deoptimization) for the de novo synthesis of an NS viral RNA segment based on influenza A/Puerto Rico/8/34 (H1N1). We generated three different recombinant influenza PR8 viruses containing codon deoptimized synonymous mutations in coding regions comprising the entire NS gene, or the mRNA corresponding to the individual viral proteins NS1 or NEP, without modifying the respective splicing and packaging signals of the viral segment. The fitness of these synthetic viruses was attenuated in vivo, while retaining immunogenicity, conferring both homologous and heterologous protection against influenza A virus challenges. These results indicate that influenza viruses can be effectively attenuated by synonymous codon deoptimization of the NS gene and open the possibility of their use as a safe vaccine to prevent infections with these important human pathogens.
IMPORTANCE:
Vaccination serves as the best therapeutic option to protect humans against influenza viral infections. However, the efficacy of current influenza vaccines is suboptimal and novel approaches are necessary for the prevention of this important human respiratory pathogen. The non-structural (NS) gene of influenza virus encodes both the multifunctional non-structural protein 1 (NS1), essential for innate immune evasion, and the nuclear export protein (NEP), required for the nuclear export of viral ribonucleoproteins and for timing of the virus life cycle. Here, we have generated a recombinant influenza A/Puerto Rico/8/1934 H1N1 (PR8) virus containing a codon deoptimized NS segment that is attenuated in vivo, yet retains immunogenicity and protection efficacy against homologous and heterologous influenza virus challenges. These results open the exciting possibility of using this NS codon deoptimization methodology alone or in combination with other approaches for the future development of vaccine candidates to prevent influenza viral infections.
Copyright ? 2014, American Society for Microbiology. All Rights Reserved.
PMID:
24965472
[PubMed - as supplied by publisher]
Influenza A virus attenuation by codon deoptimization of the NS gene for vaccine development.
Nogales A1, Baker SF1, Ortiz-Ria?o E1, Dewhurst S1, Topham DJ2, Mart?nez-Sobrido L3.
Author information
Abstract
Influenza virus infection represents a serious public health problem that causes contagious respiratory disease, which is most effectively prevented through vaccination to reduce transmission and future infection. The non-structural (NS) gene of influenza A virus encodes an mRNA transcript that is alternatively spliced to express two viral proteins, the non-structural protein 1 (NS1) and the nuclear export protein (NEP). The importance of the NS gene of influenza A for viral replication and virulence has been well described and represents an attractive target to generate live attenuated influenza viruses with vaccine potential. Considering that most amino acids can be synthesized from several synonymous codons, this study employs the use of misrepresented mammalian codons (codon deoptimization) for the de novo synthesis of an NS viral RNA segment based on influenza A/Puerto Rico/8/34 (H1N1). We generated three different recombinant influenza PR8 viruses containing codon deoptimized synonymous mutations in coding regions comprising the entire NS gene, or the mRNA corresponding to the individual viral proteins NS1 or NEP, without modifying the respective splicing and packaging signals of the viral segment. The fitness of these synthetic viruses was attenuated in vivo, while retaining immunogenicity, conferring both homologous and heterologous protection against influenza A virus challenges. These results indicate that influenza viruses can be effectively attenuated by synonymous codon deoptimization of the NS gene and open the possibility of their use as a safe vaccine to prevent infections with these important human pathogens.
IMPORTANCE:
Vaccination serves as the best therapeutic option to protect humans against influenza viral infections. However, the efficacy of current influenza vaccines is suboptimal and novel approaches are necessary for the prevention of this important human respiratory pathogen. The non-structural (NS) gene of influenza virus encodes both the multifunctional non-structural protein 1 (NS1), essential for innate immune evasion, and the nuclear export protein (NEP), required for the nuclear export of viral ribonucleoproteins and for timing of the virus life cycle. Here, we have generated a recombinant influenza A/Puerto Rico/8/1934 H1N1 (PR8) virus containing a codon deoptimized NS segment that is attenuated in vivo, yet retains immunogenicity and protection efficacy against homologous and heterologous influenza virus challenges. These results open the exciting possibility of using this NS codon deoptimization methodology alone or in combination with other approaches for the future development of vaccine candidates to prevent influenza viral infections.
Copyright ? 2014, American Society for Microbiology. All Rights Reserved.
PMID:
24965472
[PubMed - as supplied by publisher]
