Outer Membrance Protein vaccinogens of Treponema pallium

梅毒螺旋体外膜蛋白疫苗原

• 批准号: 10399446
• 负责人: Justin D Radolf
• 金额: $ 52.86万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10399446
• 关键词: Adopted; Algorithms; Antibodies; Antigens; Architecture; Bioinformatics; Biological Assay; C-terminal; Catalogs; Child; Containment; Data; Disease; Epidemiology; Escherichia coli; Family; Formulation; Genetic; Genome; Genomics; Globus Pallidus; Gram-Negative Bacteria; Human; Immune; Immune Evasion; Immune Sera; Immunization; Infection; Laboratories; Lipoproteins; Membrane; Membrane Proteins; Molecular; Molecular Chaperones; Molecular Machines; Mothers; Mus; Order Spirochaetales; Oryctolagus cuniculus; Patients; Population; Proteins; Research Personnel; Resistance; Serum; Sexually Transmitted Diseases; Societies; Structural Models; Surface; Surface Antigens; Syphilis; Testing; Translating; Treponema; Treponema pallidum; United States; Vaccine Design; Vaccines; Vertical Disease Transmission; adverse pregnancy outcome; amphiphilicity; antigen test; base; biophysical analysis; cross immunity; falls; macrophage; member; men; novel; paralogous gene; pathogen; periplasm; physical property; sex; syphilis vaccine; vaccine candidate; vaccine development

Syphilis, a sexually transmitted infection caused by the Treponema pallidum subsp. pallidum (TPA), has undergone a dramatic resurgence in the United States since the late 1990s. Syphilis also poses a major threat globally with an estimated 5.6 million new cases annually and 350,000 adverse pregnancy outcomes due to mother-to-child transmission. There is a growing sense of urgency about the need for a syphilis vaccine as a cornerstone of a strategy for global containment. Our quest to develop a syphilis vaccine began with the recognition that the outer membrane (OM) of TPA differs fundamentally from those of prototypical Gram- negative bacteria, such as E. coli. We hypothesized that TPA's `unorthodox' OM is the basis for its impressive capacity for immune evasion and that identification of TPA's repertoire of rare OM-spanning proteins (OMPs) holds the key to vaccine development. The ability of all previously tested antigens to confer at best only limited protection suggests that a syphilis vaccine will require multiple components and, consequently, the need for a pipeline of candidate vaccinogens to identify the combination that provides the greatest breadth and degree of local and systemic protection. Despite the availability of genomic sequences, until recently, syphilologists were unable to catalog the spirochete's `OMPeome'. The breakthrough came by using bioinformatics, computational, and structural algorithms to mine the TPA genome for proteins predicted to form an amphiphilic b-barrel, the structural hallmark of OM-spanning proteins. With this approach, we identified 20 candidate OMPs in TPA, which fall into two `classes': Tprs and a group of unrelated (`non-Tpr') b-barrel-forming proteins. For several (TP0326/BamA and members of Tpr subfamily I), b-barrel formation and OM localization in TPA has been validated by rigorous experimentation, and their ability to elicit potent opsonic activity also has been demonstrated. Our proposal takes the notion of `opsonic target as protective antigen' in an unbiased and novel direction: leading candidate OMP vaccinogens are selected based on genomic sequences, bioinformatics, biophysical analysis, and structural modeling, rather than whether they are recognized by immune sera generated during infection. Our pipeline consists of OMPs from four `groups': BamA, subfamily I and II Tprs, and the FadLs. In Aim 1, we will refine our topological and structural models for leading candidates in the Tpr subfamilies and FadL groups. In Aim 2, we will assess whether high titer antisera against one or more candidate OMPs promote opsonophagocytosis of TPA (an ex vivo correlate of protection) using rabbit and mouse macrophages. In Aim 3, we will determine in rabbits, and in exploratory studies with mice, if immunization with one or more OMPs provides broad as well as strong protection following challenge with diverse strains of TPA.

梅毒，一种由梅毒螺旋体亚种引起的性传播感染。苍白球 (TPA)，具有 自20世纪90年代末以来，它在美国经历了戏剧性的复兴。梅毒也构成重大威胁 全球每年估计有 560 万新发病例和 35 万例不良妊娠结局 母婴传播。人们对梅毒疫苗的需求日益迫切 全球遏制战略的基石。我们开发梅毒疫苗的探索始于 认识到 TPA 的外膜 (OM) 与典型革兰氏阴性菌的外膜有根本的不同。 阴性细菌，例如大肠杆菌。我们假设 TPA 的“非正统”OM 是其令人印象深刻的基础 免疫逃避能力以及 TPA 罕见 OM 跨越蛋白 (OMP) 库的鉴定 掌握着疫苗研发的关键。 所有先前测试的抗原最多只能提供有限的保护，这表明梅毒 疫苗将需要多种成分，因此需要一系列候选疫苗原 确定可提供最大广度和程度的局部和系统保护的组合。尽管 由于基因组序列的可用性，直到最近，梅毒学家还无法对螺旋体的 “OMPome”。这一突破是通过使用生物信息学、计算和结构算法来挖掘的 预测形成两亲性 b 桶的蛋白质的 TPA 基因组，这是 OM 跨越的结构标志 蛋白质。通过这种方法，我们在 TPA 中确定了 20 个候选 OMP，它们分为两个“类别”：Tprs 和 a 一组不相关的（“非 Tpr”）b-桶形成蛋白。对于几个（TP0326/BamA 和 Tpr 成员） 亚家族 I)、b-桶形成和 TPA 中 OM 定位已通过严格的实验验证， 并且它们引发有效调理活性的能力也已得到证明。我们的建议采用的概念是 以公正和新颖的方向“调理性靶标作为保护性抗原”：主要候选 OMP 疫苗原 根据基因组序列、生物信息学、生物物理分析和结构建模进行选择，而不是 而不是它们是否被感染期间产生的免疫血清识别。我们的管道由 OMP 组成 来自四个“组”：BamA、亚科 I 和 II Tprs 以及 FadLs。在目标 1 中，我们将完善我们的拓扑和 Tpr 亚家族和 FadL 群体中主要候选者的结构模型。在目标 2 中，我们将评估是否 针对一种或多种候选 OMP 的高效价抗血清可促进 TPA 的调理吞噬作用（一种离体 使用兔和小鼠巨噬细胞进行保护的相关性）。在目标 3 中，我们将在兔子中进行确定，并在 小鼠探索性研究，如果使用一种或多种 OMP 进行免疫可以提供广泛且强大的效果 不同 TPA 菌株挑战后的保护。