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恶性疟原虫（Pf）子孢子（SPZ）为基础的疫苗 抗疟疾，是唯一的免疫原证明诱导>90%的短期（3周）和长期 长期（至少14个月）预防受控制的人类疟疾疟原虫感染 恶性疟原虫（Pf）。使用独特的糖脂佐剂7 DW 8 -5，目标是延长 疫苗效力（VE）的持续时间，并提高在地方病环境中的效力。在小鼠模型中 使用约氏疟原虫（Py）子孢子（SPZ），我们在16周时用2个剂量和4个剂量获得> 80%的保护。 通过直接静脉途径施用irr PySPZ加7 DW 8 -5佐剂的剂量加速方案 接种（DVI）后的免疫应答，代表相对于无佐剂的irr PySPZ的2倍增强。佐剂 可以与irr PySPZ混合。高水平（>80%）的保护作用持续到16周时 PySPZ通过DVI，在7 DW 8 -5存在的情况下，但不通过非DVI路由。7 DW 8 -5的制造 在cGMP下完成，并在P. knowlesi（Pk）SPZ的试点研究中，我们实现了irr PkSPZ 50% VE，使用佐剂后无改善，可能归因于次优比较剂量，或 给药方案或短期感染性攻毒设计。由于出色的示范性 SPZ-佐剂联合疫苗在NHP中的安全性记录， 体外培养人iNKT细胞，我们建议进一步优化给药方案， 猪尾猕猴的免疫力，Pk的天然宿主，沿着保护研究，以评估 佐剂对化学减毒（PySPZ-化学预防疫苗CVac）和遗传 减毒的（PySPZ-LARC）。使用具有功能性的人源化HISA 2/hCD 1d小鼠， 人CD 8 + T细胞和人iNKT细胞（7 DW 8 -5的细胞靶），我们将研究是否存在一种 PfSPZ-7 DW 8 -5组合免疫原可增强人CD 8 + T细胞对PfSPZ的应答。 还计划在小鼠中进行佐剂相关生物标志物发现研究。走向临床应用 PfSPZ-7 DW 8 -5联合疫苗，我们将建立稳定性标准和制剂 7 DW 8 -5的生物活性方法，以及GMP级7 DW 8 -5的进一步可比性检测， 体外作为批放行属性和人源化HISA 2/hCD 1d小鼠体内，编写pre-IND包 为7 DW 8 -5-PfSPZ安全性和疗效的临床前和临床评价做准备 生产GMP 7 DW 8 -5临床使用。因为这个项目中的研究 将采用临床分级进行，充分表征7 DW 8 -5，在我们的研究中具有积极的结局 将使我们能够快速设计和进行正式的临床前毒理学和/或 符合FDA要求的生物分布研究，以更快地进入临床。完成 这一项目的完成将标志着首次研制出用于真核寄生虫活疫苗的佐剂。

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.