Improving the Translational Potential of a Prime-and-Trap Malaria Vaccine

项目摘要 疟疾是一种寄生虫病，每年造成约2.29亿人感染和40万人死亡。有效 由于寄生虫对药物治疗迅速产生抗药性，迫切需要疫苗。肝脏阶段（LS）是 是寄生虫生命周期的关键瓶颈如果停止LS，这将防止血液阶段感染， 临床疾病和传播。辐射减毒子孢子（RAS）疫苗靶向子孢子（spz） 和LS，并可通过诱导保护性抗体和CD 8 + T细胞产生灭菌保护。在临床前 研究表明，RAS诱导了一个记忆性CD 8 + T细胞亚群，这些细胞位于肝脏中，称为肝脏驻留记忆T细胞。 (Trm)对长期LS保护至关重要的细胞。尽管RAS具有高度免疫原性， 由于RAS疫苗具有许多抗原（包括环子孢子蛋白（CSP）），因此RAS疫苗的功效在不同的 人群，并且实施受到重复高剂量静脉内（IV）注射的要求的阻碍。 Prime-and-Trap是一种两步疫苗策略，旨在通过以下方式简化和改善仅RAS免疫接种 将皮内递送的编码CSP抗原的DNA与随后的单次IV剂量的RAS组合， 并“捕获”肝脏中激活和扩增的T细胞。这种策略增加了保护性CD 8+肝Trm 细胞，但依赖于单独的CSP引发抗原和需要高剂量的IV- 在捕获后施用RAS对转化到较大的动物模型和人造成障碍。这项建议 将提供临床前研究，以提高引发和陷阱疟疾的疗效和转化潜力 疫苗我们假设可以通过以下方式改善引发-陷阱：a）减少剂量或改变递送 RAS陷阱的途径，和B）通过鉴定用于引发的另外的保护性LS抗原。 在目的1中，我们将研究与糖脂佐剂7 DW 8 - 1000共同施用对RAS捕获的改善。 5.我们将评估低剂量和非IV方法递送RAS而不降低免疫原性或保护性。 在目的2中，我们将鉴定用于引发的保护性LS抗原。最近，核糖体蛋白（RP）被鉴定为 一种在小鼠中诱导保护性肝Trm细胞的有效疫苗抗原。如果有保护性，RP是有吸引力的疫苗 因为它们是高度保守和丰富的。在这里，我们将研究总体RP免疫原性， 在引发和捕获中诱导CD 8 + T细胞。这项研究将在华盛顿大学进行， 如果申请人组建了一个多学科指导小组，具有疟疾生物学、疫苗 发育和T细胞免疫学。已经设计了一个培训计划， 全球健康，会议出席和指导会议，以培养申请人的必要技能， 完成她提出的研究，成为一名独立的研究人员。简而言之，Prime-and-Trap是一个 一种多功能疟疾疫苗候选物，其可以使用单一RAS剂量诱导保护性LS免疫， 需要进一步研究以提高其翻译潜力。对这种候选疫苗的研究 为疫苗转化科学领域的候选人提供了最佳的培训机会。

PROJECT SUMMARY Malaria is a parasitic disease responsible for ~229 million infections and 400,000 deaths annually. An effective vaccine is urgently needed as parasites are rapidly growing resistant to drug treatments. The liver stage (LS) is a critical bottleneck in the parasite life cycle. If the LS was stopped, this would prevent blood stage infection, clinical disease, and transmission. Radiation-attenuated sporozoite (RAS) vaccines target the sporozoite (spz) and LS and can result in sterilizing protection by inducing protective antibodies and CD8+ T cells. In pre-clinical studies, RAS induced a subset of memory CD8+ T cells that reside in the liver called liver resident memory T (Trm) cells that were critical for long-term LS protection. Although RAS is highly immunogenic and presents many antigens (including the circumsporozoite protein (CSP)), RAS vaccine efficacy varies across different populations, and implementation is hindered by requirements for repeated high-dose intravenous (IV) injections. Prime-and-Trap is a two-step vaccine strategy intended to simplify and improve on RAS-only immunization by combining intradermally delivered DNA encoding the CSP antigen with a later single IV dose of RAS to direct and “trap” the activated and expanding T cells in the liver. This strategy increased protective CD8+ liver Trm cells in mice, but the reliance on the CSP priming antigen alone and the requirement for a high dose of IV- administered RAS upon trapping pose hurdles for translation to larger animal models and humans. This proposal will provide pre-clinical research to improve the efficacy and translational potential of the Prime-and-Trap malaria vaccine. We hypothesize that Prime-and-Trap can be improved by a) reducing the dose or altering the delivery route for the RAS trap, and b) by identifying additional protective LS antigens for priming. In Aim 1, we will investigate improvements of RAS trapping with co-administration of glycolipid adjuvant 7DW8- 5. We will evaluate low dose and non-IV methods to deliver RAS without reducing immunogenicity or protection. In Aim 2, we will identify protective LS antigens for priming. Recently, a ribosomal protein (RP) was identified as a potent vaccine antigen that induces protective liver Trm cells in mice. If protective, RP make attractive vaccine targets since they are highly conserved and abundant. Here, we will investigate overall RP immunogenicity and induction of CD8+ T cells in Prime-and-Trap. The research will be carried out at the University of Washington, where the applicant has assembled a multidisciplinary mentorship team with expertise in malaria biology, vaccine development, and T cell immunology. A training plan has been designed to provide supplemental coursework in global health, conference attendance, and mentorship meetings to build necessary skills for the applicant to complete her proposed research and become an independent researcher. In summary, Prime-and-Trap is a versatile malaria vaccine candidate that can induce protective LS immunity using a single RAS dose and warrants further investigation to improve its translational potential. The research on this vaccine candidate provides an optimal training opportunity for the candidate in the field of vaccine translational sciences.