Development of a Virus-Like Particle Vaccine for Powassan Virus

项目总结 这项提议的重点是开发一种预防鲍瓦桑病毒(POWV)相关疾病的疫苗。 POWV是一种扁虱传播的黄病毒，目前流行于北美，主要分布在东北部和北部- 位于美国中部地区，向北延伸至加拿大。由于硬蜱的传播范围不断扩大 在媒介中，POWV有可能成为一种新的病原体和公共卫生威胁。在人类中，POWV 是一种嗜神经性病毒，可导致严重的、有时是致命的脑炎和脑膜炎。我们建议 基于病毒表达产生的非复制型病毒样颗粒(VLP)抗原开发疫苗 培养细胞膜前蛋白(PRM)和包膜蛋白(E)的纯化 上清液。VLP将与几种刺激特定模式的新型疫苗佐剂之一配对 识别受体(PRRs)。每种抗原/佐剂配对都将在小鼠身上进行测试，以量化对 中和抗体和POWV特异性T细胞。我们还将详细描述B细胞和T细胞的表型 以确定疫苗驱动的反应与完整POWV感染的比较。与人类相似， 野生型实验小鼠感染POWV可导致脑部和中枢神经系统的致死性感染。因此，我们将 在小鼠POWV感染的攻击模型中也评估了疫苗的效力。接种疫苗的小鼠队列 个别抗原/佐剂配对将受到致死剂量的POWV的挑战。这些队伍将成为 在感染后多次评估提高存活率以及降低组织中的病毒载量。 这个项目完成后，我们预计将开发出一种配方最优的POWV疫苗 可以推进到临床试验，并在出现POWV时迅速动员起来。

PROJECT SUMMARY This proposal is focused on developing a vaccine for prevention of Powassan virus (POWV)- associated disease. POWV is a tick-borne flavivirus currently endemic to North America, primarily in the northeastern and north- central regions of the United States and extending north into Canada. Due to the expanding range of Ixodid tick vectors, POWV has the potential to become an emerging pathogen and public health threat. In humans, POWV is a neurotropic virus that can lead to severe, sometimes fatal encephalitis and meningitis. We propose to develop a vaccine based on non-replicating virus-like particle (VLP) antigens produced by expression of the viral pre-membrane (prM) and envelope (E) proteins in cultured cells followed by purification of VLP from the culture supernatant. VLPs will be paired with one of several novel vaccine adjuvants that stimulate specific pattern recognition receptors (PRRs). Each antigen/ adjuvant pairing will be tested in mice to quantify elicitation of neutralizing antibodies and POWV-specific T cells. We will also characterize B- and T-cell phenotypes in detail to determine how the vaccine-driven response compares to infection with intact POWV. Similarly to humans, POWV infection of wild-type laboratory mice results in lethal infection of the brain and CNS. Therefore, we will also evaluate vaccine efficacy in a challenge model of POWV infection in mice. Cohorts of mice vaccinated with individual antigen/ adjuvant pairings will be challenged with a lethal dose of POWV. These cohorts will be evaluated for increased survival, as well as, for reduction of viral load in tissues at multiple times post infection. Upon completion of this project, we expect to have developed an optimally formulated POWV vaccine which could move forward to clinical testing and be rapidly mobilized in the event of POWV emergence.