Innovative approaches to syphilis vaccine design

 描述（由申请方提供）：Syphilis是唯一一种已实现疫苗开发概念验证的细菌性STI，但James N.米勒在1973年的研究中，仅通过在37周内静脉注射60剂活动的γ辐射梅毒螺旋体就达到了这一目标。虽然显然不切实际，但这项研究强调了T. pallidum及其天然构象。我们的建议包含了这些关键概念，并联合了两个实验室小组的独立疫苗相关研究，为开发有效的梅毒疫苗提供了双管齐下的方法，该疫苗将（1）预防感染性溃疡病变的发展，以消除T。苍白球和（2）抑制密螺旋体通过宿主传播，以防止全身性疾病和后遗症。重要的是，该提案包括评估两种人类跟踪佐剂，旨在诱导保护所需的Th 1免疫应答。通过我们各自的基础研究计划，我们已经鉴定了两组独立的高度保守的密螺旋体肽，当用作免疫原时，它们抑制（a）下疳发展或溃疡形成（TprK和Tpr亚家族I的N-末端部分）和（B）宿主中的密螺旋体传播（Tp 0751 [pallilysin]）。这个建议建立在二十年来定义T保护性抗原的工作基础上。苍白球，包括重组抗原生产的优化方法（可溶性pallilysin和重折叠TprK和Tpr亚家族I）;结构分析，以建立重组蛋白是在一个接近天然的构象;基于基因组学的知识，表位保守的菌株之间的T.苍白球;仔细选择佐剂，以确保使用人类批准的制剂，产生所需的体液和细胞免疫;以及鉴定可能的保护相关性。为了实现我们开发有效的梅毒疫苗的长期目标，我们建议（1）使用仔细重折叠的重组TprK + Tpr亚家族I的保守N-末端部分和可溶性重组pallilysin，以及两种优化的人追踪定制佐剂，在兔中确定三抗原疫苗候选混合物的联合免疫保护能力;（2）确定针对梅毒的保护的相关性，包括细胞因子产生和多种抗体功能;（3）确定由在最佳定制佐剂中制备的疫苗混合物提供的免疫持续时间;和（4）测定三抗原混合物保护免受另外四种T.苍白球这些目标的成功实现将为开发一种有效和广泛保护的疫苗铺平道路，以预防目前每年影响近1100万成人，儿童和婴儿的感染。

 DESCRIPTION (provided by applicant): Syphilis is the only bacterial STI for which proof of concept for vaccine development has been achieved, yet the complete protection reported by Dr. James N. Miller in 1973 was achieved only by 60 intravenous doses of motile γ-irradiated Treponema pallidum over 37 weeks. Although obviously impractical, this study emphasized the importance of surface antigens of T. pallidum and their native conformation. Our proposal embraces those critical concepts and unites the independent vaccine-related studies of two laboratory groups, providing a two- pronged approach to development of an effective syphilis vaccine that will (1) prevent development of the infectious ulcerative lesions to abolish transmission of T. pallidum and (2) inhibit treponemal dissemination through the host to prevent systemic disease and sequelae. Importantly, this proposal includes the evaluation of two human-track adjuvants designed to induce the Th1 immune responses required for protection. Through our respective basic research programs, we have identified two separate groups of highly conserved treponemal peptides that, when used as immunogens, inhibit (a) chancre development or ulceration (the N-terminal portions of TprK and Tpr subfamily I) and (b) treponemal dissemination in the host (Tp0751 [pallilysin]). This proposal builds on a two decade history of work to define protective antigens of T. pallidum, including optimized methods for recombinant antigen production (soluble pallilysin and refolded TprK and Tpr subfamily I); structural analyses to establish that recombinant proteins are in a close-to-native conformation; genomics-based knowledge of epitopes conserved among strains of T. pallidum; careful adjuvant selection to ensure use of a human-approved formulation that generates the required humoral and cellular immunity; and identification of possible correlates of protection. To accomplish our long-term goal of developing an effective vaccine for syphilis, we propose to (1) determine the combined immunoprotective capacity of the tri-antigen vaccine candidate cocktail in rabbits, using carefully refolded recombinant conserved N-terminal portions of TprK plus Tpr Subfamily I and soluble recombinant pallilysin, with two optimized human-track custom adjuvants; (2) determine the correlates of protection against syphilis, including cytokine production and multiple antibody functions; (3) determine the duration of immunity afforded by the vaccine cocktail prepared in the optimal custom adjuvant; and (4) determine the capacity of the tri-antigen cocktail to protect against infection by four additional strains of T. pallidum. Th successful accomplishment of these aims will lead the way toward development of an effective and broadly protective vaccine to prevent an infection that currently affects nearly 11 million adults, children, and infants each year.