Boosting efficacy of oral vaccine candidates by enabling spore display of nitrated antigens

通过硝化抗原的孢子展示来提高口服候选疫苗的功效

• 批准号: 10472983
• 负责人: Aditya Mohan Kunjapur
• 金额: $ 140.63万
• 依托单位: UNIVERSITY OF DELAWARE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-08 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10472983
• 关键词: Amino Acids; Animals; Antibiotic Resistance; Antigens; Attention; Autologous; B-Cell Activation; Bacillus subtilis; Bacteria; Bacterial Antigens; Bacterial Infections; Bacterial Vaccines; Benign; Biological Models; Cells; Consumption; Disease; Educational process of instructing; Exhibits; Exposure to; Helper-Inducer T-Lymphocyte; Immune; Immune response; Immune system; Immunization; Ligands; Light; MHC Class II Genes; Mus; Oral; Organism; Patients; Peptides; Proteins; Recombinants; Reproduction spores; Role; Serotyping; Shigella; Site; Surface; Technology; Temperature; Testing; Vaccination; Vaccines; Virulence; base; delivery vehicle; design; detection platform; immune self tolerance; immunogenic; immunogenicity; insight; microbial; neoantigens; nitration; novel strategies; oral vaccine; pathogen; pathogenic bacteria; polyclonal antibody; preference; prevent; tool; vaccine candidate; vector vaccine

Project Summary Many diseases could be prevented or treated by enlisting the immune system to recognize a specific antigen. Bacterial diseases warrant heightened attention as many bacterial pathogens lack efficacious vaccines and exhibit rising rates of antibiotic resistance. These pathogens often find many ways of evading immune system detection, including varying their most immunogenic antigens. While many virulence-related proteins can be strongly conserved across pathogen serotypes, they often exhibit weak immunogenicity that is insufficient to draw the response of the immune system. In this project, we ask: Are there strategies to shine a light on live bacterial antigens for increased recognition by immune cells? Furthermore, can we couple these strategies to shelf-stable delivery vectors that are simple to administer to patients across the world? We propose a transformational approach to expand the list of candidate antigens for use in live bacterial vaccine vectors by teaching Bacillus subtilis to produce and harness an immunogenic amino acid. This amino acid has been demonstrated to terminate immune self-tolerance when substituted on the surface of autologous proteins in mice. Site-specific introduction of nitrated residues within proteins has resulted in presentation of a neoepitope that is recognized by helper T cells for subsequent activation of B cells that produce polyclonal antibodies. It stands to reason that the immunogenicity of many weakly immunogenic foreign antigens could be increased using this strategy, though this has not yet been tested. One challenge is that prior studies also established a critical but poorly understood role of the MHC Class II locus in enabling immune response to nitrated antigens. Our project will investigate the potential of spore-displayed nitrated antigens as a transformational vaccination platform for bacterial disease, with the Shigella invasion protein antigens as a model system. We will first perform animal studies with Shigella antigens that are weakly immunogenic but strongly conserved across pathogen serotypes to determine if nitration can increase their immunogenicity. To better understand where nitrated residues should be placed for optimal recognition by immune cell machinery, we will develop a high-throughput microbial display platform to screen MHC-II preference towards unnatural peptide ligands. In parallel, we will develop tools to enable site-specific incorporation of the immunogenic amino acid within proteins fused to the spore coat of B. subtilis. Recombinant spores of this non-pathogenic organism can be orally administered and maintain immunization efficacy after exposure to harsh conditions. The spore-based platform has promise to overcome limitations in the manufacture, transport, and administration of vaccines; however, the platform has low immunogenicity. Our strategy to form nitrated residues using this platform could overcome that limitation. From this project, we will gain insights about the requirements for enhanced immunogenicity due to nitration, and we will advance towards a platform technology for immunization that features shelf-stability and oral delivery.

项目摘要 通过招募免疫系统识别特定抗原，可以预防或治疗许多疾病。 细菌疾病值得加强注意力，因为许多细菌病原体缺乏有效的疫苗和 表现出抗生素耐药性的上升速度。这些病原体通常会发现许多逃避免疫系统的方法 检测，包括改变其最免疫原性的抗原。虽然许多与毒力相关的蛋白质可能是 它们在病原体血清型中强烈保守，它们通常表现出弱的免疫原性，这不足 绘制免疫系统的反应。在这个项目中，我们要求：是否有策略来阐明现场 细菌抗原可增加免疫细胞识别？此外，我们可以将这些策略与 固定稳定的送货向量易于为世界各地的患者进行管理吗？ 我们提出了一种转化方法，以扩大用于实时细菌疫苗的候选抗原清单 通过教枯草芽孢杆菌来产生和利用免疫原性氨基酸来进行载体。这个氨基酸具有 在自体蛋白表面取代时，被证明可以终止免疫自耐 在老鼠中。特定于蛋白质中硝化残基的位点引入已导致新皮子的介绍 这是由辅助T细胞识别出的，以随后激活产生多克隆抗体的B细胞。它 表明可以增加许多弱免疫原性抗原的免疫原性 使用此策略，尽管尚未进行测试。一个挑战是，先前的研究也建立了 MHC II类基因座在对硝化抗原的免疫反应中的关键但知之甚少的作用。 我们的项目将研究孢子滴硝化抗原作为转化疫苗的潜力 细菌疾病的平台，志贺氏菌入侵蛋白抗原作为模型系统。我们将首先执行 动物研究志贺氏菌抗原，具有弱免疫原性但在病原体中强烈保守 血清型确定硝化是否会增加其免疫原性。更好地了解硝化位置 残留物应通过免疫细胞机械进行最佳识别，我们将开发高通量 微生物显示平台筛选MHC-II偏好偏向非天然肽配体。同时，我们将 开发工具，以在蛋白质中的免疫原性氨基酸融合到融合的蛋白质中。 枯草芽孢杆菌的孢子涂层。可以口服这种非致病生物的重组孢子，并且 暴露于恶劣条件后，保持免疫功效。基于孢子的平台有望 克服疫苗制造，运输和给药的局限性；但是，平台有 低免疫原性。我们使用此平台形成硝化残基的策略可以克服该限制。 从这个项目中，我们将获得有关因硝酸化而增强免疫原性要求的见解。 我们将迈向采用货架稳定性和口服交付的免疫平台技术。