Universal epitopes-based recombinant influenza vaccines

项目摘要 目前诱导针对可变血凝素（HA）蛋白的毒株特异性免疫的流感疫苗接种是 不能有效地提供针对抗原性不同的流行毒株的交叉保护， 大流行病毒提高针对抗原性不同的交叉保护的通用疫苗的开发 流感病毒是高度优先事项。融合肽（FP）位于HA茎域的N端， 在甲型和B型流感病毒中普遍保守。单克隆和多克隆抗体 FP显示出广泛的中和活性。在初步数据中，我们发现了一个新的HA 2茎 结构域接近FP，其可以产生对不同亚型流感高度交叉反应的多聚IgG抗体 A病毒和两种谱系流感B病毒。神经氨酸酶（NA）表位（NA 2 e）接近酶活性 还鉴定了在所有流感A和B病毒中普遍保守的位点。NA 2 e特异性单克隆 抗体用于定量不同流感疫苗批次中的NA含量。NA豁免权被认为是 除了HA之外，还存在独立保护相关物。甲型流感病毒M2蛋白胞外结构域（M2 e）， 在甲型流感病毒中高度保守，已被证明是开发 通用甲型流感疫苗然而，单独的M2 e免疫不会提供足够高的交叉免疫效力。 保护 没有疫苗包含普遍保守的多表位，包括M2 e、FP、茎结构域和NA 2 e 已经被开发出来了。病毒样颗粒（VLP）平台已被证明是一种有前途的递送方式 免疫原性差但交叉保护性表位的载体。初步数据显示，NA 2 e单克隆 抗体能够在被动接种后提供保护。我们假设新的VLP疫苗 除了M2 e之外，诱导针对通用FP-茎结构域表位和NA 2 e表位的抗体的构建体将 增强针对不同甲型和B型流感病毒株的交叉保护效力。在目标1中，我们 确定含有FP-茎、NA 2 e（或NA）和M2 e的新的重组VLP疫苗构建体是否 表位作为独立疫苗或与HA疫苗联合使用将增强交叉保护 对抗甲型流感病毒。在目标2中，我们将确定疫苗是否诱导针对FP-干细胞的抗体 和NA 2 e表位作为独立的疫苗或当在灭活病毒疫苗中补充时， 针对B型流感病毒的交叉保护。这个为期两年的关于开发交叉的概念验证项目 诱导免疫的保护性疫苗在流感A和B病毒中普遍保守的新表位将 提供支持性数据，支持进一步的临床前研究。

PROJECT SUMMARY Current influenza vaccination inducing strain-specific immunity against variable hemagglutinin (HA) proteins is not effective in providing cross protection against antigenically different epidemic strains and unanticipated new pandemic viruses. Development of universal vaccines improving cross protection against antigenically different influenza viruses is a high priority. The fusion peptide (FP) located in the N-terminus of the stalk domain of HA is universally conserved in both influenza (flu) A and B viruses. Monoclonal and polyclonal antibodies against FP were shown to exhibit broad neutralizing activity. In preliminary data, we discovered a new HA2 stem domain near to the FP, which could generate poly IgG antibodies highly cross reactive to different subtype flu A viruses and both lineage flu B viruses. A neuraminidase (NA) epitope (NA2e) near to the enzymatic active site was also identified to be universally conserved in all flu A and B viruses. NA2e specific monoclonal antibody was used to quantitate the NA contents in different flu vaccine lots. NA immunity is considered an independent protective correlate in addition to HA. Influenza A virus M2 protein extracellular domain (M2e), which is highly conserved among flu A viruses, has been shown to be a promising target for developing universal flu A vaccines. However, M2e immunity alone would not provide sufficiently high efficacy of cross protection. No vaccines incorporating universally conserved multi epitopes including M2e, FP, stem domains and NA2e have been developed. Virus-like particle (VLP) platform has been demonstrated to be a promising delivery vehicle for poor immunogenic but cross protective epitopes. Preliminary data showed that NA2e monoclonal antibody was able to provide protection after passive inoculation. We hypothesize that new VLP vaccine constructs inducing antibodies to universal FP-stem domain epitopes and NA2e epitopes in addition to M2e will enhance the efficacy of cross protection against different strains of flu A and B viruses. In the aim 1, we will determine whether new recombinant VLP vaccine constructs containing FP-stem, NA2e (or NA), and M2e epitopes as a standalone vaccine or in combination with HA-based vaccine will enhance the cross protection against influenza A viruses. In the aim 2, we will determine whether vaccines inducing antibodies to FP-stem and NA2e epitopes as a standalone vaccine or when supplemented in inactivated virus vaccines will enhance cross protection against influenza B viruses. This proof-of-concept of two-year project on developing cross protective vaccines inducing immunity universally conserved new epitopes in both flu A and B viruses would provide supporting data warranting further advanced preclinical studies.