Optimization of novel immunogen design to elicit broadly protective immune responses against influenza viruses

项目总结 我们对广中和抗体(BNAbs)特性的理解 流感病毒表位在过去五年中迅速演变，然而，我们仍在解开关键特征。 以及这一抗体类别的功能。整个计划项目拨款的首要目标是 通过接种疫苗产生针对流感病毒的长寿、广泛保护的免疫反应。为此， 我们小组开发了新的免疫原和疫苗接种方案，在 基于嵌合血凝素(CHA)的动物模型和候选疫苗目前正朝着 I期临床试验。 项目1中提出的工作旨在推动针对群体的下一代免疫原的开发 2甲型流感病毒(IAV)和B型流感病毒(IBV)，努力克服免疫优势 HA的球形头域，并允许改进对高度保守但免疫亚显性的识别 HA表位。应用我们先前在甲型H1N1流感免疫原方面的专业知识将使我们能够迅速 推进新的第2组CHA结构。然而，真正通用的流感病毒疫苗的开发 将需要共同努力，以诱导针对第1组和第2组IAV以及IBV的bNab反应。因此， 我们建议产生新的通用B型流感病毒结构，基于 免疫优势的HA头部结构域中的哪些主要抗原位点已被消除。针对以下方面优化的CHA 第二组IAV或IBV的马赛克免疫原将以DNA、重组蛋白、灭活的形式进行测试 流感疫苗(IIV)或减毒活疫苗(LAIV)制剂在小鼠中的诱导能力 识别保守表位的广泛和保护性体液免疫反应。同时，我们将继续 使用新技术探测相互作用进一步阐明Fc介导的保护的决定因素 广泛保护的HA抗体、受感染的靶细胞和效应细胞之间的关系。这些机制将是 延伸到识别额外流感病毒抗原的抗体的作用的研究，包括 病毒神经氨酸酶(NA)，与项目4合作。这项工作计划将通过CLOSE执行 与其他每个项目的协作。我们将鉴定人类和小鼠的单抗 (单抗)由项目4和单抗核心生产。疫苗构建物将与选定的佐剂一起配制 在项目2中，看看我们是否可以增强针对保守表位的抗体反应，并在体内 铅疫苗免疫原的效力将在项目3中的雪貂模型中进行评估。因此， 我们的项目是确定广泛保护性免疫反应的独特属性，这些属性可以被利用来 进一步加强和协助开发通用流感病毒疫苗。

PROJECT SUMMARY Our understanding of the properties of broadly-neutralizing antibodies (bnAbs) directed towards conserved influenza virus epitopes has rapidly evolved in the last five years and yet, we are still unraveling key features and functions of this antibody class. The overarching goal of this entire Program Project Grant is the generation of long-lived, broadly protective immune responses to influenza virus by vaccination. To this end, our group has developed novel immunogens and vaccination regimens that have yielded promising results in animal models and candidate vaccines based on chimeric hemagglutinins (cHA) are now advancing towards Phase I clinical trials. The work proposed in Project 1, seeks to advance the development of next-generation immunogens for group 2 influenza A viruses (IAVs) and influenza B viruses (IBVs), in an effort to overcome the immunodominance of the globular head domain of HA, and allow improved recognition of highly conserved, but immunosubdominant HA epitopes. The application of our prior expertise with influenza A cHA immunogens will allow us to rapidly advance new group 2 cHA constructs. However, the development of a truly universal influenza virus vaccine will require combined efforts to elicit bnAb responses against group 1 and 2 IAVs as well as IBVs. Therefore, we propose to generate new universal influenza B virus constructs, based on novel "mosaic" HA design in which major antigenic sites in the immunodominant HA head domain have been eliminated. Optimized cHA for group 2 IAVs, or mosaic immunogens for IBVs, will be tested as DNA, recombinant protein, inactivated influenza vaccine (IIV) or live attenuated influenza vaccine (LAIV) formulations in mice for their ability to elicit broad and protective humoral immune responses recognizing conserved epitopes. In parallel, we will continue to further elucidate the determinants of Fc-mediated protection using novel techniques to probe the interactions between broadly protective HA antibodies, infected target cells, and effector cells. These mechanisms will be extended to investigations of the role of antibodies recognizing additional influenza viral antigens, including the viral neuraminidase (NA), in collaboration with Project 4. This program of work will be executed through close collaborations with each of the other Projects. We will characterize human and murine monoclonal antibodies (mAb) produced by Project 4 and the mAb Core. Vaccine constructs will be formulated with adjuvants selected in Project 2 to see if we can enhance Ab responses directed towards conserved epitopes and the in vivo efficacy of lead vaccine immunogens will be evaluated in the ferret model in Project 3. Thus, the overall aim of our project is to identify unique properties of broadly protective immune responses that can be exploited to further enhance and aid in the development of universal influenza virus vaccines.