A glycolipid adjuvant to promote dose sparing, accelerate immunization schedules and extend durability of high-level protection with an attenuated, live sporozoite malaria vaccine

我们建议进一步加强基于恶性疟原虫(PF)子孢子(SPZ)的疫苗 抗疟疾，这是唯一被证明能引起90%短期(3周)和长期的免疫原 长期(至少14个月)预防控制的人类疟疾感染疟疾 人类恶性疟原虫(PF)。使用一种独特的糖脂佐剂7DW8-5，目标是延长 疫苗效力的持续时间(VE)和在流行环境中提高效力。在小鼠模型中 用约氏疟原虫(P.yoelii(Py))子孢子(SPZ)在16周时获得80%的保护率，2剂和4剂。 IRR-PYSPZ联合7DW8-5佐剂直接静脉给药的剂量加速方案 接种(DVI)，比不加佐剂的IRR PYSPZ提高2倍。佐剂 可以与IRR PYSPZ混合使用。高水平(80%)的小鼠保护IRR持续到16周 在7DW8-5存在的情况下，通过DVI进行PYSPZ，但不通过非DVI路线。7DW8-5的制造 在cGMPs下完成了，在与P.nowlesi(Pk)SPZ的试点研究中，我们实现了IRR PkSPZ 50%的VE，使用佐剂后没有改善，可能是由于次优比较剂量或 给药方案，或短期传染病挑战设计。由于出色的可演示性 SPZ-佐剂联合疫苗在NHP中的安全性记录，以及在联合疫苗中的可比生物活性 体外培养人iNKT细胞，我们建议进一步优化给药方案，以获得持久的 PK的自然宿主--猪尾猕猴的免疫力及其保护研究 化学减毒(PYSPZ-化学预防疫苗)和遗传减毒疫苗的佐剂效应 小鼠减毒(PYSPZ-LARC)。利用具有功能性的人源化HISA2/hCD1d小鼠 人CD8+T细胞和人iNKT细胞(7DW8-5的细胞靶点)我们将研究 PfSPZ-7DW8-5联合免疫原可增强人CD8+T细胞对PfSPZ的应答。 佐剂相关的生物标记物发现研究也计划在小鼠身上进行。走向临床应用 PfSPZ-7DW8-5组合疫苗，我们将建立稳定性标准和配方 7DW8-5的方法学，以及GMP级7DW8-5生物活性的进一步可比性测试 体外作为大量释放属性和体内人源化HISA2/hCD1d小鼠，编写Pre-IND包 为7DW8-5-PfSPZ的安全性和有效性的临床前和临床评估做准备 并生产临床用GMP 7DW8-5。因为这个项目中概述的研究 将进行临床分级，很好地描述了7DW8-5，这是我们研究中的一个积极结果 将使我们能够快速设计和实施正式的临床前毒理学和/或 符合FDA要求的生物分布研究，以求更快地到达诊所。完成 该项目的实施将标志着真核寄生虫活疫苗佐剂的首次开发。

We propose to further enhance Plasmodium falciparum (Pf) Sporozoite (SPZ)-based vaccines against malaria that are the only immunogens proven to induce >90% short term (3 weeks) and long term (at least 14 months) protection against controlled human malaria infection with Plasmodium falciparum (Pf) in humans. Using a unique glycolipid adjuvant 7DW8-5, the goal is to prolong the duration of vaccine efficacy (VE) and to increase efficacy in endemic settings. In the mouse model using P. yoelii (Py) sporozoites (SPZ) we achieved > 80% protection at 16 weeks with 2 dose and 4 dose accelerated regimens of irr PySPZ plus 7DW8-5 adjuvant administered by direct venous inoculation (DVI) representing a 2-fold enhancement over irr PySPZ without adjuvant. The adjuvant could be mixed with irr PySPZ. High level (>80%) protection of mice persisted at 16 weeks with irr PySPZ by DVI, in the presence of 7DW8-5, but not by non-DVI routes. Manufacturing of 7DW8-5 under cGMPs was completed and in a pilot study with P. knowlesi (Pk) SPZ, irr PkSPZ we achieved 50% VE and no improvement with the adjuvant, likely attributable to sub-optimal comparative dose or dosing regimens, or the short-term infectious challenge design. Due to the excellent demonstrable safety record of the combined SPZ-adjuvant vaccine in NHPs, and comparable bioactivity on co- culture human iNKT cells in vitro, we propose further optimization of dosing regimens for durable immunity in pig-tailed macaques, the natural host for Pk, along with protection studies to assess adjuvant effects on chemically attenuated (PySPZ-chemoprophylaxis vaccine CVac) and genetically attenuated (PySPZ-LARC) in mice. Using humanized HISA2/ hCD1d mice possessing functional human CD8+ T cells and human iNKT cells (cellular targets of 7DW8-5) we will investigate whether a PfSPZ-7DW8-5 combination immunogen can enhance the human CD8+ T-cell response to PfSPZ. Adjuvant-associated biomarker discovery studies are also planned in mice. Towards clinical use of the PfSPZ-7DW8-5 combination vaccine, we will establish stability criteria and formulation methodologies for 7DW8-5, and further comparability testing of GMP-grade 7DW8-5 for bioactivity in vitro as a lot release attribute and humanized HISA2/ hCD1d mice in vivo, compile a pre-IND package in preparation for pre-clinical and clinical evaluation of the safety and efficacy of 7DW8-5-PfSPZ combinations, and manufacture GMP 7DW8-5 for clinical use. Because studies outlined in this project will be conducted with clinical grade, well characterized 7DW8-5, a positive outcome in our studies will place us in a position to rapidly design and conduct formal pre-clinical toxicology and/or biodistribution studies in compliance with FDA mandates for a speedier path to the clinic. Completion of this project will mark the first development of an adjuvant for a live eukaryotic parasite vaccine.