Toward a Universal Influenza Virus Vaccine

描述(由申请人提供)：针对流感病毒的广谱疫苗的开发将对现有的预防流感的医疗机构做出巨大贡献。最近的研究证明了广泛中和抗流感抗体的存在，并首次表明病毒血凝素的某些区域可以介导对流感病毒的广泛免疫。现在的挑战是，开发一种基于这些区域的疫苗，在人类中引发广谱免疫。在这项提案中，我们勾勒出了一种开发通用流感病毒疫苗的实验方法。基本策略是确定介导广泛病毒中和的血凝素表位，随后将这些表位整合到新的免疫原中，最后通过添加将使用人类体外实验系统识别的佐剂成分来增强和增强免疫原。我们将在小鼠和雪貂的疾病模型中测试免疫原和佐剂制剂。我们在本提案中概述的策略是通过大量的初步实验来开发和完善的，无论是在鉴定广谱中和抗体方面，还是在生产中。 广谱流感疫苗的原型。我们自己的初步研究，以及合作调查人员的综合专门知识，支持这项拟议工作的可行性。我们坚信，我们在这一领域的持续努力可能会产生一种提供广谱保护的流感疫苗，它比目前可用的疫苗所提供的保护要强得多。 相关性：这项拟议工作的目的是生产具有广泛保护性的流感病毒疫苗，并研究人类对流感病毒的免疫力。这里概述的实验方法是在初步实验中开发和改进的，在这些实验中，我们识别了广泛的中和抗体，并产生了原型流感免疫原，旨在提供比现有疫苗更高的广谱覆盖率。我们的初步研究以及其他小组的工作证明了广谱流感病毒疫苗的概念验证，并证明了这一疫苗设计领域的主要努力是合理的。 项目1：基于流感病毒血凝素的保守表位设计新的免疫原 项目负责人：Palese，P. 描述(由申请人提供)：拟议的工作是生产具有广泛保护性的流感病毒疫苗。我们将用来实现疫苗生产目标的基本实验方法分为两个阶段。目的1鉴定对不同流感病毒株的血凝素具有广泛保护活性的人和鼠的单抗。将努力确定这些广泛保护性抗体在血凝素分子上的准确结合区域。这项工作的目标2将涉及设计和生产新的疫苗结构，使免疫集中于那些被确定为介导广泛保护的表位。我们将构建一系列新的免疫原：一些基于血凝素的保守的、连续的、多肽区，另一些基于构象的、不连续的部分或嵌合的血凝素。疫苗接种策略将涉及使用DNA、重组纯化蛋白或纯化(嵌合)病毒。在与项目2和项目3的合作下，将通过使用补充佐剂制剂来优化疫苗结构，并将评估疫苗在小鼠和雪貂疾病模型中的有效性。 相关性：目前的流感病毒疫苗必须每年新生产，因为流行的流感病毒毒株在不断变化。我们正在尝试设计新的通用流感病毒疫苗，这种疫苗对不同的毒株具有交叉保护作用，因此寿命更长，从而避免了每年重新接种的必要性；这将通过首先识别交叉保护的单抗(针对病毒血凝素)和它们识别的准确表位/序列来实现。然后，这些表位将被用来指导疫苗构建体的设计，这些构建体可以诱导对许多不同流感病毒变种的交叉保护性免疫反应。

DESCRIPTION (provided by applicant): The development of a broad-spectrum vaccine against influenza viruses would represent a tremendous contribution to the available armamentarium against influenza. Recent studies demonstrate the existence of broadly neutralizing anti-influenza antibodies and show, for the first time, that there are regions of the viral hemagglutinin that can mediate broad immunity against influenza viruses. The challenge, now, is to develop a vaccine based on these regions that elicits broad-spectrum immunity in humans. In this proposal, we delineate an experimental approach toward the development of a universal influenza virus vaccine. The basic strategy is to identify epitopes of the hemagglutinin that mediate broad virus neutralization, to subsequently incorporate those epitopes into novel immunogens, and finally to enhance and augment the immunogens by addition of adjuvanting components that will be identified using a human ex vivo experimental system. We will test immunogens and adjuvant preparations in mice and in ferret models of disease. The strategy that we outline in this proposal was developed and refined by way of substantial preliminary experimentation both in the identification of broadly neutralizing antibodies and in the production of prototype broad-spectrum influenza vaccines. Our own preliminary studies, along with the combined expertise of the collaborating investigators, support the feasibility of this proposed work. We strongly believe that our continued efforts in this area are likely to result in an influenza vaccine that provides broad-spectrum protection that is much enhanced over that provided by currently available vaccines. RELEVANCE: The purpose of this proposed work is to generate broadly-protective influenza virus vaccines and to study human immunity to influenza viruses. The experimental approach outlined here was developed and refined during preliminary experiments in which we identified broadly neutralizing antibodies and generated prototype influenza immunogens designed to provide enhanced broad-spectrum coverage over current vaccines. Our preliminary studies along with work from other groups demonstrate proof-of-concept for broad-spectrum influenza virus vaccines and justify major efforts in this area of vaccine design. Project 1: Design of New Immunogens Based on Conserved Epitopes in the Influenza Virus Hemagglutinin Project Leader: Palese, P. DESCRIPTION (provided by applicant): The proposed work is to generate broadly-protective influenza virus vaccines. The basic experimental approach that we will use to accomplish the goal of vaccine generation is divided into two phases. Aim 1 involves characterization of human and murine monoclonal antibodies with broad protective activity against hemagglutinins of distinct influenza virus strains. Efforts will be made to determine the precise region of binding o these broadly-protective antibodies on the hemagglutinin molecule. Aim 2 of this work will involve the design and production of novel vaccine constructs that focus immunity towards those epitopes determined to mediate broad protection. We will construct a set of novel immunogens: several will be based on conserved, continuous, polypeptidic regions of the hemagglutinin, others are based on conformational, discontinuous moieties or on chimeric hemagglutinins. The vaccination strategies will involve the use of DNA, recombinantly purified protein or purified (chimeric) virus. In collaboration with Projects 2 and 3, the vaccine construct will be optimized by use of complementary adjuvant preparations and will be evaluated for efficacy in both mouse and in ferret models of disease. RELEVANCE: Present influenza virus vaccines have to be newly manufactured every year because the circulating influenza virus strains are continuously changing. We are attempting to design novel universal influenza virus vaccines which would be cross-protective against different strains and thus last longer, avoiding the necessity of annual revaccinations; this will e done by first identifying cross-protective monoclonal antibodies (directed against the viral hemagglutinin) and the precise epitopes/sequences they recognize. These epitopes will then be used to guide the design of vaccine constructs which induce cross-protective immune responses against many different influenza virus variants.