Development of a Flavivirus E Protein Fusion Loop Vaccine

描述（由申请方提供）：本提案的目的是为基于合成肽的多黄病毒疫苗的全面开发工作奠定基础。在我们之前关于黄病毒的工作中，我们小组使用噬菌体展示人库筛选产生了针对西尼罗河病毒（WNV）包膜（E）蛋白的重组单克隆抗体。出乎意料的是，抗体识别融合环，一种黄病毒E蛋白表位，其通过膜融合介导病毒进入，并且在WN病毒感染或E蛋白免疫后通常不引起抗体应答。该mAb对WN病毒感染小鼠具有保护作用，并且还可以清除正在进行的WN感染。值得注意的是，mAb还与其他几种黄病毒（如登革热病毒）反应，表明它可能具有广泛的交叉保护作用（1）。在这里，我们提出了一种重组融合环肽疫苗，靶向的单克隆抗体识别的表位，可以预防和治疗广谱的黄病毒感染，WN病毒作为我们的初始模型感染。不幸的是，代表该表位的肽在小鼠中不是高度免疫原性的。因此，我们建议合成一组改进的融合环肽，修饰以增加天然肽的免疫原性。一组肽，包括多种抗原肽修饰，将用于使用已建立的佐剂和递送技术测试该方法。然后，我们将挑战小鼠并评估体液和细胞反应。然后将评价引起应答的候选制剂的西尼罗河病毒中和能力。本提案的主要目的是评价这些候选制剂对多种黄病毒的抵抗能力，如WN病毒、Kunjin病毒、日本脑炎病毒、墨累谷脑炎病毒、圣路易斯脑炎病毒（SLEV）、登革热病毒（血清型1至4）和黄热病病毒。最后，将针对我们已建立的神经侵袭性WNV的C3 H/HeN小鼠模型在体内测试确实显示出针对WNV和针对更广泛的黄病毒组的特异性活性的任何制剂。这种广泛的肽疫苗策略的试验方法可能对多种黄病毒病原体产生深远的影响，包括目前没有疫苗的黄病毒。 公共卫生相关性：黄病毒属的人类病原体在全球范围内引起显著的发病率和死亡率。该项目旨在开发一种新的候选疫苗，可以保护人类免受各种黄病毒感染。

DESCRIPTION (provided by applicant): The goal of this proposal is to lay the foundation for a full development effort of a synthetic peptide-based multi-flavivirus vaccine. In our previous work on flaviviruses, our group produced a recombinant monoclonal antibody against West Nile virus (WNV) envelope (E) protein using a phage display human library screen. Unexpectedly, the antibody recognized the fusion loop, a flavivirus E protein epitope that mediates viral entry by membrane fusion and that does not normally elicit an antibody response following infection with WN virus or immunization with E protein. The mAb was protective against WN virus infection in mice and could also clear an ongoing WN infection. Remarkably, the mAb also reacted with several other flaviviruses, such as dengue virus, suggesting it may be broadly cross-protective (1). Here we propose that a recombinant fusion loop peptide vaccine that targets the epitope recognized by the mAb can prevent and treat a broad spectrum of flavivirus infections, with WN virus serving as our initial model infection. Unfortunately, Peptides representing this epitope are not highly immunogenic in mice. We therefore propose to synthesize a set of improved fusion loop peptides, modified to increase the immunogenicity of the native peptides. A set of peptides including, multiple antigenic peptide modifications will be used to test this approach using established adjuvant and delivery techniques. We will then challenge mice and evaluate humoral and cellular responses. Candidate formulations that elicit a response will then be evaluated for their neutralizing capacity of WNV. The main goal of this proposal is then to evaluate these candidate formulations against a broad array of Flaviviruses such as WN virus, Kunjin, Japanese encephalitis virus, Murray valley encephalitis, St. Louis encephalitis virus (SLEV), Dengue virus (serotypes 1 to 4), and Yellow fever virus. Finally, any formulations that do show both specific activity against WNV and against a broader set of flaviviruses will be tested in vivo against our well established C3H/HeN mouse Model of neuroinvasive WNV. This pilot approach to a broad based peptide vaccine strategy could have profound impact against multiple flavivirus pathogens including flaviviruses for which no vaccines are currently available. PUBLIC HEALTH RELEVANCE: Human pathogens in the Flavivirus genus cause significant morbidity and mortality worldwide. This project is designed to develop a new vaccine candidate that might protect humans against a variety of Flavivirus infections.