Nanoparticle-based vaccines against flaviviruses

描述(申请人提供)：这项提案的目标是开发基于纳米颗粒的疫苗来对抗西尼罗河病毒。西尼罗河病毒是一种新出现的人类病原体，也是登革热病毒等其他医学上重要的黄病毒的模型。我们和其他人已经证明，由截短形式的黄病毒包膜蛋白组成的重组亚单位疫苗可以保护动物免受其他致命病毒的挑战。在这里，我们建议将重组包膜蛋白包裹在由聚(乳酸-乙醇酸)(PLGA)制成的可生物降解的纳米颗粒核心中，PLGA经过修饰后加入了免疫调节剂。我们的假设是，这种配方将克服重组亚单位疫苗开发的传统方法中发现的许多弱点。首先，配制的抗原有望在室温下长时间稳定。其次，接种疫苗可以通过无针操作(口服或鼻腔给药)进行。最后，我们的结果表明，用PLGA颗粒免疫可以引起强烈的细胞免疫反应，这是完全消除传染性病毒的基本机制。我们将合成包括西尼罗河病毒包膜蛋白在内的PLGA颗粒。PLGA颗粒将包括不同浓度的CpG寡核苷酸作为佐剂。然后，我们将用PLGA制剂对小鼠进行皮下、口服和鼻腔免疫。我们将改变免疫接种的次数和疫苗的剂量。将对免疫反应进行详细描述。特别是，我们将监测病毒中和抗体以及病毒特异性T细胞的出现。我们将验证免疫在一种不同品系的老鼠身上也是有效的。此外，我们还将评估纳米颗粒在储存过程中的稳定性。最后，用我们的西尼罗河病毒疫苗免疫的小鼠将受到其他致命剂量的活病毒的挑战。我们希望发现，接种疫苗的动物现在能在这样的挑战中幸存下来。公共卫生相关性：西尼罗河病毒和登革热病毒等黄病毒会导致严重的人类疾病和死亡。我们建议开发一种针对这些病毒引起的疾病的疫苗。疫苗抗原将是从病毒包膜中提取的重组蛋白，并将被包裹在纳米颗粒中。这将使我们能够口服或滴鼻接种疫苗。

DESCRIPTION (provided by applicant): The objective of this proposal is to develop nanoparticle-based vaccines against West Nile virus. West Nile virus is an emerging human pathogen and a model for other medically important flaviviruses such as dengue virus. We and others have shown that a recombinant subunit vaccine consisting of a truncated form of the flaviviral envelope protein can protect animals from otherwise lethal viral challenges. Here we propose to encapsulate recombinant envelope proteins in biodegradable nanoparticulate cores fabricated from poly(lactic-co-glycolic acid) (PLGA) which have been modified to incorporate immune modulators. Our hypothesis is that this formulation will overcome many weaknesses found in traditional approaches to recombinant subunit vaccine development. First, the formulated antigen is expected to be stable at room temperature for extended periods of time. Second, vaccination can occur with a needle-free procedure (oral or intranasal administration). Finally, our results have shown that immunization with PLGA particles elicits a strong cellular immune response, an essential mechanism to fully eliminate infectious virus. We will synthesize PLGA particles including the envelope protein from West Nile virus. The PLGA particles will include varying concentrations of CpG oligonucleotides as an adjuvant. We will then immunize mice, subcutaneously, orally, and intranasally, with the PLGA preparations. We will vary the number of immunizations and the dose of vaccine administered. The immune response will be characterized in detail. In particular, we will monitor the appearance of virus-neutralizing antibodies as well as virus-specific T cells. We will verify that the immunization is also effective in a distinct strain of mice. Furthermore, we will evaluate the stability of the nanoparticles during storage. Finally, mice immunized with our vaccine against West Nile virus will be challenged with an otherwise lethal dose of live virus. We expect to find that vaccinated animals now survive such a challenge. PUBLIC HEALTH RELEVANCE: Flaviviruses such as West Nile virus and dengue virus cause significant human disease and death. We propose to develop a vaccine against diseases caused by these viruses. The vaccine antigen would be a recombinant protein derived from the viral envelope, and would be encapsulated in nanoparticles. This would allow us to administer the vaccine orally or intranasally.