CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 YueYang Road, Shanghai 200031, China.
CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 YueYang Road, Shanghai 200031, China; Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 MeiLong Road, Shanghai 200237, China.
Vaccine. 2018 Aug 6;36(32 Pt B):4837-4845. doi: 10.1016/j.vaccine.2018.06.048. Epub 2018 Jun 28.
H1N1, one of the most prevalent influenza A virus subtypes affecting the human population, can cause infections varying from mild respiratory syndrome to severe pneumonia. The current H1N1 vaccine needs to be updated annually and does not protect against future outbreaks. Here, we downloaded 2,656 HA protein sequences of human H1N1 viruses from the NCBI influenza database (up to the date of Aug. 2012) and constructed a phylogenetic tree of these H1 proteins via the neighbor-joining method using MEGA 5.0 software. A consensus H1 protein (CH1) was generated and was further modified with published conserved T-cell and B-cell epitopes. Interestingly, this CH1 protein is genetically similar to an H1 isolate obtained during the 1980s (A/Memphis/7/1980), indicating that a universal HA antigen may exist in nature. Vaccination with a DNA vaccine expressing CH1 elicited broadly reactive T-cell and B-cell responses to heterologous H1N1 viruses, though this vaccine did not successfully neutralize pdm09 H1N1 viruses. A combination of CH1 and pdm09 HA in a DNA vaccination neutralized pdm09 H1N1 viruses and protected mice from lethal infections by all representative H1N1 viruses. Moreover, a recombinant chimeric PR8-CH1 virus carrying HA sequence of the consensus H1 and all other seven genes from the PR8 strain was highly attenuated in mice, with a lethal dose (LD) of more than 10 pfu. Vaccination with PR8-CH1 virus provided complete protection against infections by heterologous H1N1 strains. Taken together, a universal H1 antigen, CH1, was developed by constructing a consensus HA sequence, and the PR8-CH1 virus containing this consensus sequence elicited broadly protective immunity against heterologous H1N1 viruses.
H1N1 是一种流行的影响人类的甲型流感病毒亚型，可引起从轻度呼吸道综合征到严重肺炎等不同程度的感染。目前的 H1N1 疫苗需要每年更新，不能预防未来的爆发。在这里，我们从 NCBI 流感数据库中下载了 2656 个人类 H1N1 病毒的 HA 蛋白序列（截至 2012 年 8 月），并通过 MEGA 5.0 软件的邻接法构建了这些 H1 蛋白的系统发育树。生成了一个共识 H1 蛋白（CH1），并进一步修改了已发表的保守 T 细胞和 B 细胞表位。有趣的是，这种 CH1 蛋白在遗传上与 20 世纪 80 年代获得的 H1 分离株（A/Memphis/7/1980）相似，表明自然界中可能存在通用的 HA 抗原。用表达 CH1 的 DNA 疫苗进行免疫接种，可引起针对异源 H1N1 病毒的广泛反应性 T 细胞和 B 细胞反应，但该疫苗未能成功中和 pdm09 H1N1 病毒。在 DNA 疫苗接种中，CH1 和 pdm09HA 的组合可中和 pdm09H1N1 病毒，并保护小鼠免受所有代表性 H1N1 病毒的致死性感染。此外，携带共识 H1 的 HA 序列和来自 PR8 株的所有其他七个基因的重组嵌合 PR8-CH1 病毒在小鼠中高度减毒，LD 超过 10 pfu。用 PR8-CH1 病毒免疫接种可提供针对异源 H1N1 株感染的完全保护。总之，通过构建共识 HA 序列，开发了一种通用的 H1 抗原 CH1，含有该共识序列的 PR8-CH1 病毒可引起针对异源 H1N1 病毒的广泛保护性免疫。
