M2 peptide based vaccines against influenza

描述（由申请人提供）： 甲型流感病毒的年度流行导致超过32，000人死亡，仅在美国就有120，000人住院治疗。通常由人类和禽流感病毒株的基因组区段重配引起的甲型流感病毒的抗原组成的突然变化可导致与数十万人死亡相关的世界范围的大流行，最臭名昭著的是1918年的流感大流行，估计在全世界造成2000万人死亡。目前的流感疫苗由预期在人群中传播的灭活病毒株组成，该灭活病毒株基于上一日历年分离的毒株-鉴于流感病毒的变异倾向，这一过程耗时且固有风险。生产具有针对多种病毒株的活性的流感疫苗不仅可以减轻流感对当前人群的负担，还可以保护个人免受生物恐怖分子引发的目前不在人群中传播的甲型流感病毒株的释放。 M2蛋白是这种疫苗的有吸引力的候选物，因为M2的氨基酸序列在迄今为止测序的所有人甲型流感病毒株中几乎相同，并且甲型流感病毒M2蛋白胞外结构域的抗体可以保护小鼠免受致死剂量的甲型流感病毒的攻击。 目前的甲型流感病毒疫苗不能有效地诱导针对M2蛋白的抗体，因为M2在病毒颗粒中的代表性严重不足。肝炎核心平台将用于将M2的胞外区表达为杂合核心颗粒（核心-M2 e），并将通过血清抗体ELISA和保护小鼠免受甲型流感病毒攻击来评估其在免疫小鼠中诱导免疫应答的功效。Core-M2 e将单独使用或作为当前流感疫苗的补充，以确定哪种疫苗接种方法可增强对具有抗原性不同的HA和NA亚型的甲型流感病毒株的保护。由于猪和禽流感A病毒株的M2序列与人株的M2序列不同，我们将产生并表征含有这些序列的核心颗粒诱导对携带禽、猪或人M2序列的流感A病毒株的保护性免疫的能力。最后，我们将研究M2抗体在体内提供保护的机制，并表征M2抗体逃逸突变体的复制和毒力。

DESCRIPTION (provided by applicant): Annual epidemics of influenza A virus are responsible for over 32,000 deaths, 120,000 hospitalizations in the United States alone. Sudden shifts in the antigenic makeup of influenza A virus, usually caused by genome segment reassortment of human and avian influenza virus strains, can lead to worldwide pandemics that have been associated with hundreds of thousands of deaths, the most notorious being the 1918 influenza pandemic estimated to have caused 20 million deaths worldwide. The current influenza vaccine consists of inactivated virus strains expected to circulate in the human population based on strains isolated in the previous calendar year - a process that is time consuming and inherently risky given the propensity of influenza virus to mutate. Generating an influenza vaccine with activity against a variety of virus strains would not only ease the burden of influenza on the current population but also protect individuals from a bioterrorist-initiated release of an influenza A virus strain not currently circulating in the human population. The M2 protein is an attractive candidate for such a vaccine because the amino acid sequence of M2 is nearly identical in all human strains of influenza A virus sequenced to date and antibodies to the influenza A virus M2 protein extracellular domain can protect mice from challenge with a lethal dose of influenza A virus. Antibodies to the M2 protein are not efficiently induced by the current influenza A virus vaccine because M2 is grossly underrepresented in the virus particle. The hepatitis core platform will be used to express the extracellular region of M2 as a hybrid core particle (core-M2e) and its efficacy in inducing an immune response in immunized mice will be assessed by serum antibody ELISA and protection of mice from influenza A virus challenge. Core-M2e will be used by itself or as a supplement to the current influenza vaccine to determine which vaccination approach confers increased protection to influenza A virus strains bearing antigenically distinct HA and NA subtypes. Since the M2 sequence of swine and avian influenza A virus strains differs from that of human strains, we will generate and characterize the ability of core particles containing these sequences to induce protective immunity to influenza A virus strains bearing avian, swine or human M2 sequences. Finally, we will investigate the mechanism by which M2 antibodies confer protection in vivo and characterize the replication and virulence of M2 antibody escape mutants.