Developing Vault Nanoparticles as a Delivery Platform for Burkholderia pseudomallei and Burkholderia mallei Antigens

开发 Vault 纳米颗粒作为类鼻疽伯克霍尔德杆菌和鼻疽伯克霍尔德杆菌抗原的递送平台

• 批准号: 10120425
• 负责人: Christopher Todd French
• 金额: $ 5.51万
• 依托单位: NORTHERN ARIZONA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-06-12 至 2021-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10120425
• 关键词: Developing; Vault; Nanoparticles; Delivery; Platform

ABSTRACT Burkholderia pseudomallei (Bp) is endemic to tropical regions and causes the often-fatal disease melioidosis in humans and animals, posing a significant threat to native residents, tourists, and deployed U.S. military personnel. In highly-endemic areas of southeast Asia, melioidosis is projected to surpass tuberculosis as the second most common cause of infectious disease mortality after HIV/AIDS. There are currently no effective approaches for providing immunity, and treatment confounded by intrinsic antibiotic resistance. The ability to survive intracellularly and utilize membrane fusion as a means for spreading from cell to cell shelters the bacterium from the humoral immune system. Prior efforts to provide protective immunity against Bp rely on live-attenuated strains or bacterial subunits that are only partially protective. Therefore, an antigen-delivery strategy to elicit both antibody and cellular responses is needed for B. pseudomallei, and the factors that promote survival inside mammalian cells will likely constitute effective antigens. This is supported by current evidence in animal models and recovered melioidosis patients, where cytotoxic T lymphocytes (CTLs) play a central role by recognizing and killing Bp-infected cells, with antibody playing an ancillary role. Our goal is to utilize the endogenous human vault nanoparticle as a novel, safe platform for delivering Burkholderia antigens that can elicit strong cell-mediated and humoral responses against Bp. Vaults efficiently deliver antigens and provide remarkable immune responses without additional adjuvants. Vaults are large, naturally-occurring, cytoplasmic riboprotein particles found in all nucleated mammalian cells. Recent observations suggest that vaults function in immune surveillance, delivering antigens from dying cells to facilitate adaptive immunity. Recombinant vaults efficiently deliver antigens to both the MHC class I and II pathways, and have adjuvant-like effects in APCs, eliciting protective CD4 and CD8 T cell responses, while also generating antibody responses. In contrast, native or "empty" vaults do not activate inflammasome or TLR-dependent inflammatory reactions and are non-immunogenic. We have exploited these properties of vaults to elicit robust immune responses in several systems, including a mouse model of mucosal infection by intracellular Chlamydia, which like Bp, is an intracellular pathogen. We will combine our considerable knowledge of pathogenic mechanisms and practiced production approaches for making recombinant vaults containing Burkholderia antigens (BurkAgs). BurkAgs have been identified based on properties that are hypothesized to correlate with robust immunogenicity and the potential to elicit broad responses against diverse strains of Bp. The ability of recombinant BurkVaults to induce antigen-specific antibody, CD4 and CD8 T cell responses following i.n. or s.c. immunization will be determined in established, quantitative assays. Recombinant vaults that display optimal structural, compositional, and immunogenic profiles will be advanced for studies against lethal challenge with Bp in BALB/c mice.

摘要 假鼻疽伯克霍尔德氏菌(BP)是热带地区特有的一种致死性疾病。 在人类和动物中，对当地居民、游客和部署的美军构成重大威胁 人事部。在东南亚高度流行的地区，类鼻疽预计将超过结核病，成为 仅次于艾滋病毒/艾滋病的第二大传染病死亡原因。目前还没有有效的 提供免疫力的方法，以及因固有的抗生素耐药性而混乱的治疗。有能力 在细胞内存活，并利用膜融合作为一种在细胞之间传播的手段来保护细菌 来自体液免疫系统。先前对BP提供保护性免疫的努力依赖于减毒活疫苗 仅具有部分保护作用的菌株或细菌亚基。因此，一种抗原传递策略可以同时诱导 假鼻疽杆菌需要抗体和细胞反应，以及促进其存活的因素。 哺乳动物细胞很可能构成有效的抗原。目前在动物模型中的证据支持这一点。 和康复的类鼻疽患者，其中细胞毒性T淋巴细胞(CTL)通过识别和 杀灭BP感染的细胞，抗体起辅助作用。我们的目标是利用内源性人体保险库 纳米颗粒作为一种新颖、安全的平台来传递伯克霍尔德氏菌抗原，可以诱导出强大的细胞介导的和 针对BP的体液反应。保险库有效地运送抗原，并提供显著的免疫反应 没有额外的佐剂。拱顶是大的，自然发生的，细胞质核蛋白颗粒，在所有 有核的哺乳动物细胞。最近的观察表明，保险库在免疫监视中发挥作用，提供 来自死亡细胞的抗原，以促进适应性免疫。重组金库有效地将抗原传递给 MHC I和II类通路，在APC中具有佐剂样效应，诱导保护性的CD4和CD8T细胞 反应，同时也产生抗体反应。相比之下，原生或“空”存储区不会激活 炎症体或TLR依赖的炎症反应，是非免疫原性的。我们已经利用了这些 拱顶的特性在几个系统中引发强大的免疫反应，包括小鼠粘膜模型 与BP一样，细胞内衣原体感染也是一种细胞内病原体。我们将把我们相当可观的 了解致病机理和制作重组拱顶的实用生产方法 含有伯克霍尔德氏菌抗原(BurkAgs)。BurkAgs是基于以下属性识别的 假设与强大的免疫原性相关，并有可能引发针对不同 BP菌株。重组BurkVaults诱导抗原特异性抗体、CD_4、CD_8 T细胞的能力 在I.N.之后的答复。或者南加州大学。免疫将在既定的定量分析中确定。重组 显示最佳结构、成分和免疫原性轮廓的拱顶将被推进，用于研究 BP对BALB/c小鼠的致死性攻击。