DNA Vaccine for Seasonal & Pandemic Influenza

描述(由申请人提供)：开发新的流感疫苗的一个重大挑战是确定既能加快疫苗生产又能预防出现流行病和大流行毒株的战略。这项提议将开发一种DNA疫苗来满足这些需求。DNA疫苗可以快速设计和制造，以表达多种抗原，并诱导抗体和细胞介导的保护作用，防止远距离漂移变异体。这项建议将采用DNA疫苗的颗粒介导的表皮递送(PMEd)，并建立在最近成功的季节性流感PMEd DNA疫苗的基础上，该疫苗在I期人体临床试验中在接种对象中诱导保护性抗体水平。这项建议的目的是提高PMEd DNA疫苗的免疫原性，并进一步将该疫苗开发为大流行流感产品。该提案的主要目标是：1)通过包括多个HA序列来扩大疫苗对遗传漂移毒株和禽流感的特异性。2)研究核蛋白(NP)基因在多价DNA疫苗中的作用，并对其序列进行修改和优化，以增加针对该基因高度保守区域的CD8T细胞反应的广度和效力。3)确定我们已经展示的一种新的基因佐剂是否可以增强针对其他DNA疫苗抗原的抗体和细胞免疫反应，是否同样可以提高候选大流行流感DNA疫苗的免疫原性和保护效力。该疫苗将在高度相关的雪貂和非人类灵长类临床前模型中进行免疫原性测试。将开发猕猴模型，以利用分析T细胞免疫所需的该物种I类基因座上可用的信息。将采用雾化流感挑战，以便在模拟人口自然暴露的环境中评估对同源和漂移的禽流感毒株的保护效果。这些努力将产生三种候选DNA疫苗产品，它们可以诱导抗体和细胞免疫反应，以预防季节性和大流行流感病毒株。这些实验还将检验这样一种假设，即疫苗诱导针对病毒保守区域的CD8 T细胞反应将提高对HA-DRIFE变种的保护效力，并对新出现的流感病毒大流行毒株造成的死亡提供关键保护。

DESCRIPTION (provided by applicant): A significant challenge for the development of new influenza vaccines is to identify strategies that can both accelerate vaccine production and protect against the emergence of epidemic and pandemic strains. This proposal will develop a DNA vaccine to meet these needs. DNA vaccines can be rapidly designed and manufactured to express multiple antigens and induce antibody and cell-mediated protection against distant drift variants. This proposal will employ particle-mediated epidermal delivery (PMED) of the DNA vaccine and builds on the recent success of a seasonal influenza PMED DNA vaccine that induced protective levels of antibody in vaccinated subjects in a phase I human clinical trial. The purpose of this proposal is to increase PMED DNA vaccine immunogenicity and further develop the vaccine as a pandemic flu product. The primary objectives of the proposal are to: 1) Broaden the specificity of the vaccine against genetically drifted strains and avian influenza by including multiple HA sequences. 2) Investigate the effects of including a nucleoprotein (NP) gene in the multivalent DNA vaccine with sequences modified and optimized to increase the breadth and potency of CD8+ T cell responses against highly conserved regions of the gene. 3) Determine if a novel genetic adjuvant that we have shown enhances antibody and cellular immune responses against other DNA vaccine antigens will similarly increase the immunogenicity and protective efficacy of the candidate pandemic influenza DNA vaccine. The vaccine will be tested for immunogenicity in the highly relevant ferret and nonhuman primate preclinical models. A model in rhesus macaques will be developed to take advantage of the information available on the Class I locus of this species required for analysis of T cell immunity. Aerosolized influenza challenges will be employed so that protective efficacy against homologous and drifted strains of avian influenza can be evaluated in a setting that mimics natural exposure in the population. These efforts will generate three candidate DNA vaccine products that induce antibody and cellular immune responses for protection against both seasonal and pandemic strains of influenza. These experiments will also test the hypothesis that vaccine induction of CD8+ T cell responses against conserved regions of the virus will increase protective efficacy against HA-drift variants and provide critical protection against mortality caused by emerging pandemic strains of influenza viruses.