Novel VLP vaccines for pandemic influenza virus

描述(申请人提供)：野生水禽中存在大量人类尚未接触到的禽流感病毒，高致病性H5N1禽流感病毒株目前在东南亚几个国家流行，它们已导致数十人死亡。这些菌株特别令人担忧，因为它们对最具成本效益的抗病毒药物金刚烷胺和金刚乙胺具有抗药性。如果出现一种新的传染性流感病毒，而人们对这种病毒几乎没有免疫力，就会导致一场全球大流行，而目前还没有疫苗可用。目前的流感疫苗是由适应在鸡胚鸡蛋中生长良好的病毒生产的，而高致病性禽流感病毒对鸡蛋是致命的，这使得目前的疫苗生产方法存在问题。因此，迫切需要开发有效流感疫苗的替代方法。为了努力开发流感疫苗生产的替代品并应对大流行威胁，我们在这个项目中的目标是确定流感病毒样颗粒疫苗是否能够对高致病性禽流感病毒提供保护性免疫。其他目标是解决目前流感疫苗的其他缺点：它们显示出有限的效力，它们不能预防粘膜表面的感染，而且观察到的免疫是高度毒株特异性的，持续时间很短。因此，我们将开发方法来增强流感疫苗的免疫原性，增强对疫苗的记忆反应，并在粘膜表面诱导有效的免疫反应，从而对更广泛的病毒株具有保护作用。除了一组监测体液和细胞免疫反应的分析外，我们还将利用已经构建的新型转基因小鼠来直接测量免疫反应产生的B细胞记忆的大小。该项目的具体目标是：1.生产含有流感病毒糖蛋白和基质(M1)蛋白的病毒样颗粒；2.表征流感病毒样颗粒免疫后的体液和细胞免疫反应及其保护效果；以及3.通过引入针对抗原提呈细胞的VLP配体，开发更有效的流感VLP疫苗。

DESCRIPTION (provided by applicant): A large spectrum of avian influenza virus to which the human population is na?ve is present in wild aquatic birds, and highly pathogenic H5N1 avian strains are currently circulating in several countries in Southeast Asia where they have caused dozens of human fatalities. These strains are of particular concern because they are resistant to the most cost-effective antiviral drugs, amantadine and rimantadine. The emergence of a novel transmissible influenza virus against which the population has little or no immunity would cause a global pandemic, for which no vaccine is available. Current influenza vaccines are produced from viruses that are adapted to grow well in embryonated hens' eggs, whereas highly pathogenic avian influenza viruses are lethal for hens' eggs, making the current methods of vaccine production problematic. Alternative approaches to develop effective influenza vaccines are therefore urgently needed. In an effort to develop alternatives for influenza vaccine production and in response to a pandemic threat, our goal in this project is to determine whether influenza virus-like particle based vaccines will provide protective immunity against a highly pathogenic avian influenza virus. Additional goals are to address other shortcomings of current influenza vaccines: they exhibit limited efficacy, they fail to protect against infection at mucosal surfaces, and the observed immunity is highly strain-specific and of short duration. Thus, we will develop approaches to enhance the immunogenicity of influenza vaccines, to enhance memory responses to the vaccine, and to induce effective immune responses at mucosal surfaces which may be protective against a broader range of viral strains. In addition to a panel of assays to monitor humoral and cellular immune responses, we will make use of novel transgenic mice which have been constructed to directly measure the magnitude of B cell memory generated in response to immunization. The specific aims of the project are: 1. to produce virus-like particles (VLPs) incorporating influenza viral glycoproteins and matrix (M1) protein; 2. to characterize humoral and cellular immune responses after immunization with influenza VLPs and their protective efficacy; and 3. to develop more effective influenza VLP-based vaccines by incorporation of ligands designed to target the VLPs to antigen-presenting cells.