Institute for Viral Disease Control and Prevention, China CDC, Changbai Road 155, Beijing, 102206, China.
Vaccine. 2012 Oct 12;30(46):6527-33. doi: 10.1016/j.vaccine.2012.08.054. Epub 2012 Sep 7.
Vaccination is the most effective means for preventing influenza-associated morbidity and mortality. Since the influenza virus mutates frequently, the virus strains for new vaccine production should be changed according to predicted epidemic strains. The extracellular domain of matrix protein 2 (M2e) is 24 amino acids long, which is highly conserved and therefore a good target for the development of a universal vaccine which may protect against a much wider range of influenza A virus strains. However its low antigenicity and immunogenicity, which are related to its small size, poses a big challenge for vaccine development. Multiple antigen peptide system (MAP) is based on an inert core molecule of radially branching lysine dendrites onto which a number of peptide antigens are anchored. Tuftsin is an immuno-stimulant molecule peptide. Here we developed a novel peptide vaccine by connecting a tuftsin to a branched, four-copy M2e. Not only did this increase the molecular mass, but also potentiate the immunogenicity. Two branched peptides, (M2e)4-tuftsin and (M2e)4-G4(tuftsin was replaced with four glycines), and a M2e monomer were synthesized using standard solid-phase methods. In vitro and in vivo studies were performed to compare their antigenicity and immunogenicity. Experiments in BALB/c mice demonstrated that the branched M2e could induce stronger humoral and cellular immune responses than the M2e monomer, and (M2e)4-tuftsin induced stronger humoral and cellular immune response than (M2e)4-G4. After lethal challenge with influenza virus PR8 strain, up to 80% of the animals in the (M2e)4-tuftsin vaccinated group still survived, in contrast to 44% in the (M2e)4-G4 group and 30% in the M2e monomer group. The combination of branched polypeptides and tuftsin in vaccine design is presented here for the first time, and the results show that the new construct is a promising candidate for a universal vaccine against the influenza A virus.
疫苗接种是预防流感相关发病率和死亡率的最有效手段。由于流感病毒频繁变异，新疫苗生产用的病毒株应根据预测的流行株进行更换。基质蛋白 2（M2）的细胞外结构域（M2e）由 24 个氨基酸组成，高度保守，因此是开发通用疫苗的良好靶点，这种疫苗可能对更广泛范围的流感 A 病毒株具有保护作用。但是，由于其抗原性和免疫原性较低，与它的小尺寸有关，这给疫苗的开发带来了很大的挑战。多抗原肽系统（MAP）是基于惰性核心分子的，该核心分子为放射状分支赖氨酸树突，其上连接了多个肽抗原。Tuftsin 是一种免疫刺激分子肽。在这里，我们通过将一个 tuftsin 连接到一个分支的、四拷贝的 M2e 上来开发一种新型肽疫苗。这不仅增加了分子量，而且增强了免疫原性。两个分支的肽（M2e）4-tuftsin 和（M2e）4-G4（tuftsin 被四个甘氨酸取代）以及一个 M2e 单体，使用标准的固相方法进行合成。进行了体外和体内研究以比较它们的抗原性和免疫原性。在 BALB/c 小鼠中的实验表明，分支的 M2e 能够诱导比 M2e 单体更强的体液和细胞免疫应答，并且（M2e）4-tuftsin 诱导比（M2e）4-G4 更强的体液和细胞免疫应答。在致命性流感病毒 PR8 株攻击后，高达 80％的（M2e）4-tuftsin 疫苗接种组的动物仍然存活，而（M2e）4-G4 组为 44％，M2e 单体组为 30％。分支多肽和 tuftsin 在疫苗设计中的组合在这里是首次提出的，结果表明，新构建体是针对流感 A 病毒的通用疫苗的有希望的候选物。
