Nanoparticle-based vaccines against flaviviruses

描述（由申请人提供）：本提案的目标是开发针对西尼罗病毒的纳米颗粒疫苗。西尼罗河病毒是一种新兴的人类病原体，也是其他医学上重要的黄病毒（如登革热病毒）的模型。我们和其他人已经证明，由黄病毒包膜蛋白的截断形式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攻击。在这里，我们建议将重组包膜蛋白封装在由聚乳酸-羟基乙酸（PLGA）制成的可生物降解的纳米粒核中，这些纳米粒核经过了免疫调节剂的修饰。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，期望配制的抗原在室温下长时间保持稳定。第二，疫苗接种可以通过无针程序（口服或鼻内给药）进行。最后，我们的研究结果表明，PLGA颗粒免疫引起强烈的细胞免疫反应，这是完全消除感染性病毒的重要机制。我们将合成含有西尼罗病毒包膜蛋白的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、口服和鼻内免疫。我们将改变免疫接种的次数和接种疫苗的剂量。免疫反应将被详细描述。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的小鼠品系中也有效。此外，我们将评估纳米颗粒在储存期间的稳定性。最后，用我们的西尼罗病毒疫苗免疫的小鼠将受到致命剂量的活病毒的攻击。我们希望发现接种过疫苗的动物现在能在这样的挑战中生存下来。公共卫生相关性：黄病毒如西尼罗河病毒和登革热病毒引起重大人类疾病和死亡。我们建议研制一种疫苗来对付由这些病毒引起的疾病。疫苗抗原将是一种从病毒包膜中提取的重组蛋白，并被包裹在纳米颗粒中。这将使我们能够口服或鼻内注射疫苗。

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.