Mechanisms of Protection of Universal Therapeutic Antibodies to Influenza A

流感病毒感染会导致人和动物的传染性呼吸道疾病，并导致严重的发病率 以及全球范围内的死亡率。人类未能对流感做出普遍的保护性记忆免疫反应 A，作为血凝素和神经氨酸酶，这两个免疫主导的甲型流感病毒编码表位， 经历抗原性的转移和漂移，导致甲型流感病毒株，即使是以前感染的人类也是如此 易受影响。在没有通用甲型流感疫苗、预防或治疗剂的情况下，甲型流感 仍将是对人类健康的重大威胁。为了生成这样的代理，我们开发了一个矩阵面板 蛋白2细胞外(M2e)特异性单抗(MAb)。M2-离子的胞外区 Channel是一种通用治疗剂的理想抗原靶点：它在甲型流感中保持99%的保守性 血清型，突变率低，对病毒进入和复制是必不可少的。然而，只有不到20%的 受感染的人产生M2e特异性抗体来应对甲型流感，可能是由于 M2E的体积很小，而且很罕见。因此，我们寻求实现我们的长期目标，发展一个普遍的 预防或治疗甲型流感感染和相关病理的预防或治疗剂，通过 提供M2e特异性单抗，这是保护性甲型流感特异性免疫反应的重要组成部分 目前大多数人类都缺乏这种能力。为了实现这一目标，我们产生了七种针对 M2E，其中两种完全保护，三种部分保护高度敏感的甲型流感病毒 BALB/c小鼠免受致死攻击。基于这些考虑，我们的中心假设是 M2E特异性单抗可以预防或改善甲型流感感染和相关病理。作为抗体 可以调节多种有助于宿主保护的互补效应器功能，我们假设 能够干扰M2离子通道活性的M2e特异性单抗的组合，引发了 ADCC、吞噬和补体激活将是减少甲型流感病毒复制的最有效方法 以及相关的病理，同时防止免疫逃逸。我们希望测试我们的中心假设，并 通过追求以下三个具体目标来实现本应用程序的目标：目标1：确定 单抗结合对M2e功能和病毒复制的生物学效应；目标2：建立保护性和 体内治疗性单抗治疗方案；和目标3：剖析M2e特异性的个体贡献 依赖单抗的细胞毒性、吞噬和补体激活对甲型流感病毒宿主保护作用的研究 感染。为了实现我们的目标，我们召集了由合作科学家组成的专家团队：比顿博士，一位 离子通道功能专家；汤普金斯博士，人类和人畜共患流感动物模型专家 感染、疫苗接种和治疗学，具有特定的M2专业知识；罗斯博士，雪貂模型方面的专家 流感疫苗接种和感染；还有，我自己，Paust博士，一位详细的 了解甲型流感感染的先天和获得性免疫反应。

Influenza virus infection causes contagious respiratory illness in humans and animals, and significant morbidity and mortality worldwide. Humans fail to make a universally protective memory immune response to influenza A, as Hemagglutinin and Neuraminidase, the two immune-dominant influenza A virus-encoded epitopes, undergo antigenic shift and drift, resulting in influenza A strains to which even previously infected humans are susceptible to. In the absence of a universal influenza A vaccine, prophylactic or therapeutic agent, influenza A will remain a significant threat to human health. To generate such agents, we developed a panel of Matrix Protein 2 extracellular (M2e)-specific monoclonal antibodies (MAbs). The extracellular domain of the M2-ion channel is an ideal antigenic target for a universal therapeutic agent: It is 99% conserved across influenza A serotypes, has a low mutation rate, and is essential for viral entry and replication. However, less than 20% of infected individuals generate M2e-specific antibodies in response to influenza A infection, perhaps due to M2e's small size and rarity. Thus, we seek to accomplish our long-term goal, to develop a universal prophylactic or therapeutic agent to prevent or treat influenza A infection and associated pathologies, by provision of M2e-specific MAbs, an essential component of a protective influenza A-specific immune response currently lacking in most humans. To achieve this goal, we generated seven monoclonal antibodies specific to M2e, two of which completely protect, and three of which partially protect highly influenza A virus susceptible Balb/c mice from lethal challenge. Based on these considerations, it is our central hypothesis that a cocktail of M2e-specific MAbs can prevent or ameliorate influenza A infection and associated pathology. As antibodies can mediate a variety of complementary effector functions that contribute to host protection, we hypothesize that a combination of M2e-specific MAbs capable of interference with M2-ion channel activity, elicitation of ADCC, phagocytosis and complement activation will be most effective at reducing influenza A virus replication and associated pathology, while preventing immune escape. We expect to test our central hypothesis and to achieve the objective of this application by pursuing the following three specific aims: Aim 1: to identify biological effects of MAb binding on M2e-function and viral replication in vitro; Aim 2: to develop protective and therapeutic MAb treatment regimens in vivo; and Aim 3: to dissect the individual contributions of M2e-specific MAb-dependent cytotoxicity, phagocytosis and complement activation to host protection from influenza A virus infection. To achieve our aims, we have assembled and expert team of collaborating scientists: Dr. Beeton, an expert in the ion channel function; Dr. Tompkins, an expert in animal models of human and zoonotic influenza infection, vaccination, and therapeutics, with specified M2 expertise; Dr. Ross, an expert in the ferret model of influenza vaccination and infection; and, myself, Dr. Paust, an expert immunologist with a detailed understanding of the innate and adaptive immune response to Influenza A infection.