Nogales Aitor, Baker Steven F, Ortiz-Riaño Emilio, Dewhurst Stephen, Topham David J, Martínez-Sobrido Luis
Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA.
Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA New York Influenza Center of Excellence, University of Rochester, Rochester, New York, USA Center for Biodefense and Immune Modeling, University of Rochester, Rochester, New York, USA David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, New York, USA.
J Virol. 2014 Sep;88(18):10525-40. doi: 10.1128/JVI.01565-14. Epub 2014 Jun 25.
Influenza viral 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 nonstructural (NS) gene of influenza A virus encodes an mRNA transcript that is alternatively spliced to express two viral proteins, the nonstructural protein 1 (NS1) and the nuclear export protein (NEP). The importance of the NS gene of influenza A virus 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 employed the use of misrepresented mammalian codons (codon deoptimization) for the de novo synthesis of a viral NS RNA segment based on influenza A/Puerto Rico/8/1934 (H1N1) (PR8) virus. 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 protein 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 they retained 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.
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 disease cause by this important human respiratory pathogen. The nonstructural (NS) gene of influenza virus encodes both the multifunctional nonstructural 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.
流感病毒感染是一个严重的公共卫生问题，可引发传染性呼吸道疾病，通过接种疫苗减少传播和未来感染是预防该病最有效的方法。甲型流感病毒的非结构（NS）基因编码一种mRNA转录本，该转录本经过可变剪接以表达两种病毒蛋白，即非结构蛋白1（NS1）和核输出蛋白（NEP）。甲型流感病毒NS基因对病毒复制和毒力的重要性已得到充分描述，是产生具有疫苗潜力的减毒活流感病毒的一个有吸引力的靶点。鉴于大多数氨基酸可由多个同义密码子合成，本研究采用错误呈现的哺乳动物密码子（密码子去优化），从头合成基于甲型流感病毒/波多黎各/8/1934（H1N1）（PR8）病毒的病毒NS RNA片段。我们产生了三种不同的重组流感PR8病毒，它们在包含整个NS基因或与单个病毒蛋白NS1或NEP对应的mRNA的编码区域含有密码子去优化的同义突变，同时未改变病毒片段各自的剪接和包装信号。这些合成病毒在体内的适应性减弱，同时保留了免疫原性，对甲型流感病毒攻击提供同源和异源保护。这些结果表明，通过对NS基因进行同义密码子去优化可有效减弱流感病毒，并为将其用作预防这些重要人类病原体感染的安全疫苗开辟了可能性。
接种疫苗是保护人类免受流感病毒感染的最佳治疗选择。然而，目前流感疫苗的效果并不理想，需要新的方法来预防这种重要的人类呼吸道病原体引起的疾病。流感病毒的非结构（NS）基因既编码对先天免疫逃避至关重要的多功能非结构蛋白1（NS1），也编码病毒核糖核蛋白核输出及病毒生命周期定时所需的核输出蛋白（NEP）。在此，我们产生了一种重组甲型流感病毒/波多黎各/8/1934（H1N1）（PR8）病毒，其含有一个密码子去优化的NS片段，该片段在体内减弱但保留免疫原性以及对同源和异源流感病毒攻击的保护效力。这些结果为单独使用这种NS密码子去优化方法或与其他方法结合用于未来开发预防流感病毒感染的候选疫苗开辟了令人兴奋的可能性。
