Developing a Multivalent Subunit Particle Vaccine Against Tuberculosis

项目总结 可能需要一种有效的疫苗来减轻全球结核病(TB)的负担。One的开发 一直很困难，部分原因是结核分枝杆菌(Mtb)能够长期居住 在宿主抗原(Ag)提呈细胞(APC)内，它表达大量的AGs，其中许多具有 已成为疫苗研发的目标。重组AGS一直是众多疫苗的焦点， 然而，临床测试的结果并不理想。此R61/R33建议书是对计划的响应 公告RFA-AI-21-007：“结核病疫苗发现的创新”将利用下一个- 疫苗佐剂系统，诱导重组AGS的无缝颗粒形成，以评估 多价结核杆菌疫苗。将在结合(通过SIMPLE)的基础上提出新的免疫范例 混合)特性良好的可溶性蛋白Mtb AGS与疫苗佐剂混合，可诱导自发性 纳米脂质体-银颗粒化。含有少量钴卟啉-磷脂的脂质体 (CoPoP)通过在双层中自发插入His标记的AGS而与His标记的AGS结合。这种方法提供了 上升到在生物介质中稳定的快速颗粒化。重组AGS与CoPoP简单混合 接种时的脂质体(无需进一步提纯)被完全转化以在表面展示 ~100 nm的颗粒。CoPoP最近完成了第一阶段，并作为关键进入第二阶段临床测试 新冠肺炎疫苗(NCT04783311)的组成部分。CoPoP还可以通过Short诱导强大的细胞反应 在小鼠中注射纳克多肽时，MHC-I限制多肽免疫原；多个数量级以下 与使用常规疫苗佐剂的Ag剂量进行比较。初步数据显示， 用已建立的Mtb AGS Ag85A、CFP10、ESAT-6、HSP-X和Mpt64修饰的多价颗粒 在小鼠体内诱导保护性细胞免疫反应。基本的假设是，多价粒子- 基于Mtb AGS诱导的保护性免疫反应比卡介苗更有效。 Guérin(卡介苗)在多种小动物结核病感染模型中的应用。建议书的R61阶段将使用鼠标 结核病感染的模型：(1)发展特征良好的多价结核分枝杆菌抗原颗粒；(2)评估颗粒 影响功能免疫原性的参数；以及(3)鼻腔和肌肉内注射的效果比较 粒子管理。在A的基础上提出了雄心勃勃的、量化的R61-R33过渡里程碑) 生成具有储存稳定性的表征良好的颗粒，其中B)多价AgS提供了优越的 相对于最佳单个银粒子的保护作用，C)优于常规卡介苗免疫小鼠。 该项目的R33阶段将包括(4)在豚鼠模型中评估疫苗，以及(5)开发 以及评估冷冻干燥的耐热版本疫苗的有效性和毒性。

PROJECT SUMMARY An effective vaccine is likely required to reduce the global burden of tuberculosis (TB). Development of one has been difficult, in part due to the ability for Mycobacterium tuberculosis (Mtb) to reside for long periods within host antigen (Ag) presenting cells (APCs), where it expresses a multitude of Ags, many of which have been targeted for vaccine development. Recombinant Ags have been the focus of numerous vaccines, however outcomes to clinical testing have been less than ideal. This R61/R33 proposal in response to program announcement RFA-AI-21-007: “Innovation for Tuberculosis Vaccine Discovery” will leverage a next- generation, vaccine adjuvant system that induces seamless particle-formation of recombinant Ags to assess a multivalent Mtb vaccine. A new immunization paradigm will be advanced, based on combining (via simple mixing) well-characterized soluble protein Mtb Ags with a vaccine adjuvant that induces spontaneous nanoliposome-Ag particleization. Liposomes that contain small amounts of cobalt porphyrin-phospholipid (CoPoP) bind to his-tagged Ags via spontaneous insertion of the his-tag into the bilayer. This approach gives rise to rapid particleization that is stable in biological media. Recombinant Ags are simply admixed with CoPoP liposomes at the time of vaccination (without further purification) to be fully converted for display on the surface of ~100 nm particles. CoPoP recently completed phase I and entered phase II clinical testing as a key component of a COVID-19 vaccine (NCT04783311). CoPoP also induces potent cellular responses using short MHC-I restricted peptide immunogens at nanogram peptide dosing in mice; multiple orders of magnitude lower dosing compared to Ag doses with conventional vaccine adjuvants. Preliminary data demonstrates that multivalent particles decorated with the established Mtb Ags Ag85A, CFP10, ESAT-6, HSP-X, and Mpt64 induce protective cellular immune responses in mice. The underlying hypothesis is that multivalent, particle- based Mtb Ags will induce a potently protective immune responses more effective than Bacillus Calmette– Guérin (BCG) in multiple small animal models of TB infection. The R61 phase of the proposal will use mouse models of TB infection to: (1) Develop well-characterized, multivalent Mtb Ag particles; (2) Assess how particle parameters impact functional immunogenicity; and (3) Compare the efficacy of intranasal and intramuscular particle administration. Ambitious and quantitative R61-R33 transitional milestones are proposed based on A) generating well-characterized particles with storage stability with B) multivalent Ags providing superior protection relative to the best single Ag particles with C) superiority to conventional BCG immunization in mice. The R33 phase of the project will involve (4) assessing the vaccine in the guinea pig model, and (5) developing and assessing the efficacy and toxicity of a lyophilized thermostable version of the vaccine.