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 许多疾病可以通过免疫系统识别特定抗原来预防或治疗。 细菌性疾病值得高度关注，因为许多细菌性病原体缺乏有效的疫苗， 抗生素耐药性的增长率。这些病原体往往找到许多方法逃避免疫系统 检测，包括改变其最具免疫原性的抗原。虽然许多与毒力相关的蛋白质可以 它们在病原体血清型中高度保守，通常表现出弱免疫原性， 引起免疫系统的反应。在这个项目中，我们问：有没有策略来照亮生活 细菌抗原增加免疫细胞的识别？此外，我们能否将这些策略与 储存稳定的传递载体，易于向世界各地的患者施用？ 我们提出了一种转化方法来扩大用于活细菌疫苗的候选抗原的列表 通过教导枯草芽孢杆菌产生和利用免疫原性氨基酸来构建载体。这种氨基酸具有 已经证明，当在自体蛋白质的表面上取代时， 对小鼠在蛋白质内位点特异性引入硝化残基导致了新表位的呈现 它被辅助T细胞识别，随后激活产生多克隆抗体的B细胞。它 许多弱免疫原性的外源抗原的免疫原性可以增加 使用这种策略，虽然这还没有被测试过。一个挑战是，先前的研究也建立了一个 MHC II类基因座在使对硝化抗原的免疫应答中的关键但知之甚少的作用。 我们的项目将研究孢子展示硝化抗原作为转化疫苗的潜力 细菌性疾病的平台，以志贺氏菌侵袭蛋白抗原作为模型系统。我们将首先表演 用免疫原性弱但在病原体间高度保守的志贺氏菌抗原进行的动物研究 血清型，以确定硝化是否可以增加其免疫原性。为了更好地了解硝化 残基应该被放置在免疫细胞机器的最佳识别，我们将开发一种高通量的 微生物展示平台来筛选MHC-II对非天然肽配体的偏好。同时，我们将 开发工具以使得能够将免疫原性氨基酸位点特异性地掺入融合至免疫原性氨基酸的蛋白质内。 B孢子被。枯草杆菌。该非致病性生物体的重组孢子可以口服施用， 在暴露于恶劣条件后保持免疫效力。基于孢子的平台承诺， 克服了疫苗生产、运输和管理方面的限制;然而，该平台 免疫原性低。我们使用这个平台形成硝化残基的策略可以克服这一限制。 从这个项目中，我们将获得有关硝化作用增强免疫原性的要求的见解， 我们将朝着具有储存稳定性和口服给药特点的免疫平台技术发展。