Engineered Nanoparticles for Protective Subunit Vaccine Delivery and Discovery

项目摘要 结核分枝杆菌（Mtb）是引起结核病（TB）的细菌病原体， 20亿人，每年造成150万人死亡。结核病的全球负担是巨大的，而且还在不断增加， 而有效的疫苗将为这一问题提供最佳的长期解决方案。然而，这种疫苗 仍然不存在。阻碍开发有效结核疫苗的主要障碍包括 对哪些抗原决定簇赋予保护性免疫的不完全理解， 免疫接种策略能够引发记忆性CD 8+和CD 4 + T细胞应答， 明确的感染本项目的目标是设计和评估一种创新的纳米粒子（NP） 经工程改造以引发稳健且持久的肺CD 8+和CD 4 + Th 1记忆T细胞应答的疫苗 抗结核杆菌抗原将开发和优化NP用于Mtb表位和5'末端的双重递送。 三磷酸化RNA（5 'ppp-RNA），一种胞质模式识别受体（PRR）的激动剂， 酸诱导基因1（RIG-I）作为疫苗佐剂具有巨大的未开发潜力。我们特别 建议利用NP疫苗的独特递送能力来增强肺Th 1和CD 8 + T细胞 对确定的和临床相关的Mtb MHC I类和II类限制性表位的应答，以及 自然加工的I类限制性表位。我们已经召集了一个强大的 拥有药物输送、疫苗设计和开发、RNA工程、 表位发现和Mtb感染的小鼠模型。因此，我们处于理想的位置， 1）开发一种纳米颗粒疫苗，其增强肺驻留的CD 8 + 和Th 1记忆T细胞对Mtb亚单位抗原的应答; 2）评估免疫原性和保护性 天然加工的Mtb表位的潜力。在目标1中，我们将研究鼻内NP 免疫对肺抗原/佐剂递送和细胞内摄取的量级和动力学的影响， 阐明5 ′ ppp-RNA的免疫刺激佐剂作用，并严格表征肺和 对Mtb抗原的系统性CD 4+和CD 8 + T细胞应答。在目标2中，我们将使用纳米粒来递送新型结核分枝杆菌 I类限制性表位，单独和与已建立的免疫显性II类Mtb组合 表位，表征局部和全身性T细胞应答，并评估疫苗保护免受 肺结核挑战。该项目将产生一种新的疫苗技术，用于增强粘膜细胞 亚单位疫苗的免疫力，将扩大疫苗佐剂的医疗设备，并将提供一种工具， 使免疫原性和保护性Mtb表位的发现成为可能。通过结合表位发现工作 通过合理设计的运载系统，成功完成拟议的研究将建立一个 新的和潜在的变革性范例的T细胞靶向疫苗的合理设计。

PROJECT SUMMARY Mycobacterium tuberculosis (Mtb) is a bacterial pathogen that causes tuberculosis (TB), a disease that afflicts 2 billion people and results in 1.5 million deaths each year. The global burden of TB is enormous and growing, and an effective vaccine would provide the best long-term solution to this problem. However, such a vaccine still does not exist. Major barriers that have hindered the development of an effective TB vaccine include an incomplete understanding of which antigenic determinants confer protective immunity and a dearth of vaccination strategies capable of eliciting memory CD8+ and CD4+ T cell responses that can rapidly respond to and clear infection. The objective of this project is to design and evaluate an innovative nanoparticle (NP) vaccine engineered to elicit robust and durable pulmonary CD8+ and CD4+ Th1 memory T cell responses against Mtb antigens. NPs will be developed and optimized for dual-delivery of Mtb epitopes and 5' triphosphorylated RNA (5'ppp-RNA), an agonist of the cytosolic pattern recognition receptor (PRR) retinoic acid-inducible gene 1 (RIG-I) that has immense untapped potential as a vaccine adjuvant. Specifically, we propose to harness the unique delivery capabilities of NP vaccines to enhance pulmonary Th1 and CD8+ T cell responses to established and clinically relevant Mtb MHC class I- and class II-restricted epitopes as well as naturally processed class I-restricted epitopes recently discovered by our team. We have assembled a strong multidisciplinary team with expertise in drug delivery, vaccine design and development, RNA engineering, epitope discovery, and mouse models of Mtb infection. Therefore, we are ideally positioned to accomplish our objective through the following Specific Aims: 1) Develop a nanoparticle vaccine that elicits lung-resident CD8+ and Th1 memory T cell responses to Mtb subunit antigens; 2) Evaluate the immunogenicity and protective potential of naturally processed Mtb epitopes. In Aim 1, we will investigate the effect of intranasal NP immunization on the magnitude and kinetics of pulmonary antigen/adjuvant delivery and intracellular uptake, elucidate the immunostimulatory adjuvant effects of 5'ppp-RNA, and rigorously characterize pulmonary and systemic CD4+ and CD8+ T cell responses to Mtb antigens. In Aim 2, we will use NPs to deliver novel Mtb class I-restricted epitopes, both alone and in combination with an established immunodominant class II Mtb epitope, characterize local and systemic T cell responses, and assess the ability of vaccines to protect against pulmonary Mtb challenge. This project will result in a new vaccine technology for enhancing mucosal cellular immunity to subunit vaccines, will expand the armamentarium of vaccine adjuvants, and will provide a tool that empowers the discovery of immunogenic and protective Mtb epitopes. By combining epitope discovery efforts with rationally engineered delivery systems, successful completion of the proposed research will establish a new and potentially transformative paradigm for the rational design of T cell-targeted vaccines.