Outer Membrance Protein vaccinogens of Treponema pallium

梅毒，一种由梅毒螺旋体引起的性传播感染。苍白球（TPA）， 自20世纪90年代末以来，它在美国经历了戏剧性的复苏。系统也构成了一个重大威胁 据估计，全球每年有560万例新病例和35万例不良妊娠结局， 母婴传播梅毒疫苗作为一种预防梅毒的药物， 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）与原型革兰氏阳性菌的外膜（OM）根本不同， 阴性菌如E.杆菌我们假设TPA的“非正统”OM是其令人印象深刻的基础， 免疫逃避能力和TPA稀有跨OM蛋白（OMP）库鉴定 是疫苗研发的关键 所有以前测试过的抗原最多只能提供有限的保护作用，这表明梅毒抗原可能是一种免疫缺陷病毒。 疫苗将需要多种成分，因此，需要候选疫苗原的管道， 确定提供最大范围和程度的地方和系统保护的组合。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 “OMPeome”。这一突破是通过使用生物信息学、计算和结构算法来挖掘 TPA基因组的蛋白质预测形成一个两亲性的b桶，结构标志的OM跨越 proteins.通过这种方法，我们确定了TPA中的20个候选OMP，它们分为两个“类”：TMPs和 一组不相关的（“非Tpr”）b-桶形成蛋白。对于几个（TP 0326/BamA和Tpr成员） 亚家族I），b-桶形成和TPA中的OM定位已经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实。我们的建议采用了 “调理素靶作为保护性抗原”的新方向：领先的候选OMP疫苗原 基于基因组序列、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时产生的免疫血清识别。我们的管道由OMP组成 从四个“组”：BamA，亚家族I和II TcB，和FadL。在目标1中，我们将改进我们的拓扑结构， Tpr亚家族和FadL组中主要候选者的结构模型。在目标2中，我们将评估 针对一种或多种候选OMP的高滴度抗血清促进TPA的调理吞噬作用（离体 保护的相关性）。在目标3中，我们将在兔子中确定， 用小鼠进行的探索性研究，如果用一种或多种OMP免疫提供了广泛和强的 保护后的挑战与不同菌株的TPA。

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.