Anti-galactose-α-1,3-galactose (anti-α-Gal) antibody is naturally expressed at a high level in humans. It constitutes about 1% of immunoglobulins found in human blood. Here, we designed a live attenuated influenza virus vaccine that can generate α-Gal epitopes in infected cells in order to facilitate opsonization of infected cells, thereby enhancing vaccine-induced immune responses. In the presence of normal human sera, cells infected with this mutant can enhance phagocytosis of human macrophages and cytotoxicity of NK cells in vitro Using a knockout mouse strain that allows expression of anti-α-Gal antibody in vivo, we showed that this strategy can increase vaccine immunogenicity and the breadth of protection. This vaccine can induce 100% protection against a lethal heterosubtypic group 1 (H5) or group 2 (mouse-adapted H3) influenza virus challenge in the mouse model. In contrast, its heterosubtypic protective effect in wild-type or knockout mice that do not have anti-α-Gal antibody expression is only partial, demonstrating that the enhanced vaccine-induced protection requires anti-α-Gal antibody upon vaccination. Anti-α-Gal-expressing knockout mice immunized with this vaccine produce robust humoral and cell-mediated responses upon a lethal virus challenge. This vaccine can stimulate CD11blo/- pulmonary dendritic cells, which are known to be crucial for clearance of influenza virus. Our approach provides a novel strategy for developing next-generation influenza virus vaccines.IMPORTANCE Influenza A viruses have multiple HA subtypes that are antigenically diverse. Classical influenza virus vaccines are subtype specific, and they cannot induce satisfactory heterosubtypic immunity against multiple influenza virus subtypes. Here, we developed a live attenuated H1N1 influenza virus vaccine that allows the expression of α-Gal epitopes by infected cells. Anti-α-Gal antibody is naturally produced by humans. In the presence of this antibody, human cells infected with this experimental vaccine virus can enhance several antibody-mediated immune responses in vitro Importantly, mice expressing anti-α-Gal antibody in vivo can be fully protected by this H1N1 vaccine against a lethal H5 or H3 virus challenge. Our work demonstrates a new strategy for using a single influenza virus strain to induce broadly cross-reactive immune responses against different influenza virus subtypes.

中文翻译：

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在感染的细胞中表达半乳糖-α-1,3-半乳糖表位的活的减毒流感病毒疫苗诱导的异型保护。

抗半乳糖-α-1,3-半乳糖（抗α-Gal）抗体在人类中自然高水平表达。它构成了人类血液中约1％的免疫球蛋白。在这里，我们设计了一种减毒活流感病毒活疫苗，可以在受感染的细胞中产生α-Gal表位，以促进受感染细胞的调理作用，从而增强疫苗诱导的免疫反应。在正常人血清的存在下，感染此突变体的细胞可以在体外增强人巨噬细胞的吞噬作用和NK细胞的细胞毒性。使用允许在体内表达抗α-Gal抗体的敲除小鼠品系，我们证明了这种策略可以增加疫苗的免疫原性和保护范围。该疫苗可在小鼠模型中针对致命的异型1组（H5）或2组（小鼠适应的H3）流感病毒激发诱导100％保护。相反，其在不具有抗α-Gal抗体表达的野生型或基因敲除小鼠中的异型保护作用仅是部分的，表明增强的疫苗诱导的保护在接种疫苗后需要抗α-Gal抗体。用这种疫苗免疫的表达抗α-Gal的基因敲除小鼠在致命病毒攻击后会产生强大的体液和细胞介导的反应。这种疫苗可以刺激CD11blo /-肺树突状细胞，这对于清除流感病毒至关重要。我们的方法为开发下一代流感病毒疫苗提供了一种新颖的策略。重要信息甲型流感病毒具有多种抗原性多样的HA亚型。经典的流感病毒疫苗是亚型特异性的，它们不能诱导令人满意的针对多种流感病毒亚型的异型免疫。在这里，我们开发了一种减毒的H1N1流感病毒活疫苗，可以使被感染的细胞表达α-Gal表位。抗α-Gal抗体是人类天然产生的。在存在这种抗体的情况下，感染此实验性疫苗病毒的人细胞可以增强体外的几种抗体介导的免疫反应。重要的是，这种H1N1疫苗可以充分保护体内表达抗α-Gal抗体的小鼠免受致命的H5或H3病毒挑战。