Nanoparticle-based vaccines against flaviviruses

描述（由申请方提供）：本提案的目的是开发针对西尼罗河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。我们和其他人已经表明，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-羟基乙酸共聚物（PLGA）制成的可生物降解的纳米颗粒核心中，该纳米颗粒核心已被修改为包含免疫调节剂。我们的假设是，这种配方将克服许多弱点，发现在传统的方法重组亚单位疫苗的发展。首先，预期配制的抗原在室温下长时间稳定。第二，疫苗接种可以通过无针程序（口服或鼻内施用）进行。最后，我们的研究结果表明，用PLGA颗粒免疫激发了强烈的细胞免疫应答，这是完全消除感染性病毒的重要机制。我们将合成PLGA颗粒，包括来自西尼罗河病毒的包膜蛋白。PLGA颗粒将包含不同浓度的CpG寡核苷酸作为佐剂。然后，我们将用PLGA制剂皮下、口服和鼻内免疫小鼠。我们将改变免疫接种的数量和疫苗的剂量。将详细描述免疫应答。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。我们将验证免疫在不同品系的小鼠中也有效。此外，我们将评估纳米颗粒在储存期间的稳定性。最后，用我们的西尼罗河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，导致重大人类疾病和死亡。我们建议研制一种疫苗来预防由这些病毒引起的疾病。疫苗抗原将是来自病毒包膜的重组蛋白，并将被封装在纳米颗粒中。这将使我们能够口服或鼻内接种疫苗。

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.