Development of a Virus-Like Particle Vaccine for Powassan Virus

项目摘要 该提案的重点是开发一种预防Powassan病毒（POWV）相关疾病的疫苗。 POWV是一种蜱传黄病毒，目前在北美流行，主要在东北部和北部， 美国中部地区，向北延伸到加拿大。由于硬蜱的传播范围不断扩大 由于POWV是一种重要的传染媒介，它有可能成为一种新的病原体和公共卫生威胁。在人类中， 是一种嗜神经病毒，可导致严重的，有时是致命的脑炎和脑膜炎。我们建议 开发一种基于非复制型病毒样颗粒（VLP）抗原的疫苗，所述VLP抗原通过表达病毒样颗粒（VLP）抗原而产生。 前膜（prM）和包膜（E）蛋白，然后从培养物中纯化VLP 上清液。VLP将与几种新型疫苗佐剂中的一种配对， 识别受体（PRRs）。将在小鼠中测试每种抗原/佐剂配对，以定量抗原/佐剂的诱导。 中和抗体和POWV特异性T细胞。我们还将详细描述B和T细胞表型 以确定疫苗驱动的反应与完整的POWV感染相比如何。与人类相似， 野生型实验室小鼠的POWV感染导致脑和CNS的致死性感染。所以我们会 还在小鼠中的POWV感染的攻击模型中评价疫苗效力。接种以下疫苗的小鼠队列 将用致死剂量的POWV攻击单个抗原/佐剂配对。这些部队将是 评价存活率的增加以及感染后多次组织中病毒载量的减少。 该项目完成后，我们预计将开发出一种最佳配方的POWV疫苗， 可以进行临床试验，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.