Rational design of transferrin binding protein-based vaccines to combat gonorrhea

人类病原体淋病奈瑟菌(Ngo)能够利用人类转铁蛋白作为唯一来源。 铁制的。人转铁蛋白(HTF)的高效铁转运需要TonB依赖的整合型表达 外膜转运蛋白(TbpA)和表面暴露的脂蛋白(TbpB)。Tbps的表达式为 淋球菌在男性志愿者研究中确定人类感染所必需的，这意味着 人类宿主中的这些蛋白质。因为这个运输系统是由所有淋球菌和蛋白质表达的 组分被很好地保存，它们作为疫苗靶标的潜力将在这项提案中得到探索。这个 在拟议的研究中要检验的最重要的假设是，合理设计的疫苗包括 改造的TbpA和TbpB抗原，与实验选择的佐剂相结合，将提供 对无症状定植和致病性炎症的免疫交叉保护 不同的淋病奈瑟菌菌株。该方案的具体目标如下：目标1.合理设计 基于TBP的疫苗。在这一目标中，将定义有无HTF的淋球菌TBP的结构。这些 结构将指导突变努力，以产生在配基结合上有缺陷和缺乏的疫苗抗原 结构破坏最小的超变量序列。目标2.优化人性化疫苗投放 雌性小鼠下生殖道感染模型。佐剂、给药路线、剂量和时间表 在女性下生殖道感染模型中使用人源化小鼠表达的最佳保护测试 HTF。免疫学相关因素和保护决定因素将通过广泛检测体液和 细胞免疫因子。目的3.TBP疫苗对新型人源化感染的保护效果测试 模特们。优化的抗原、佐剂、路线和时间表将在人源化小鼠身上进行保护测试 盆腔炎、男性尿道炎、鼻咽部感染模型。再一次，免疫学 在这些新的感染动物模型中，将描述保护的相关性和决定因素。目标4. 评估合理设计的疫苗在所有感染模式中的交叉保护作用。优化的，合理的- 将对设计的疫苗配方进行测试，以防止广泛的NGO毒株，包括 抗菌素耐药的“超级细菌”菌株。免疫学上的保护性关联将用这些来验证 所有人源化小鼠感染模型中的菌株。这些研究具有重要意义，因为它们可能会导致 对一种顽固的病原体产生抗药性的有效疫苗的开发 现有的治疗方法。这些研究是创新的，因为他们将使用结构导向疫苗 设计开发与配体结合的无能疫苗抗原，假想显示增强 与野生型蛋白的免疫原性比较。此外，这些抗原将在 将定义新的人源化小鼠感染模型和免疫学保护相关因素，结束 我们在理解对NGO的免疫力方面存在一个关键差距。

The human pathogen, Neisseria gonorrhoeae (Ngo) is capable of utilizing human transferrin as the sole source of iron. Efficient iron transport from human transferrin (hTf) requires expression of a TonB-dependent, integral outer membrane transporter (TbpA), and a surface-exposed lipoprotein (TbpB). Expression of the Tbps is necessary for the gonococcus to establish human infection in male volunteer studies, implying a critical role for these proteins in the human host. Because this transport system is expressed by all gonococci and the protein components are well conserved, their potential as vaccine targets will be explored in this proposal. The overarching hypothesis to be tested in the proposed study is that a rationally-designed vaccine consisting of engineered TbpA and TbpB antigens, combined with an experimentally selected adjuvant, will provide immunologic cross-protection against both asymptomatic colonization and pathogenic inflammation caused by diverse N. gonorrhoeae strains. The specific aims of the proposal are as follows: Aim 1. Rational design of Tbp-based vaccines. In this aim, structures of the gonococcal Tbps will be defined with and without hTf. These structures will guide mutagenesis efforts to produce vaccine antigens defective in ligand binding and lacking hypervariable sequences with minimal structure disruption. Aim 2. Optimizing vaccine delivery in humanized female mouse model of lower genital tract infection. Adjuvants, delivery routes, doses and schedules will be tested for optimal protection in the female lower genital tract infection model using humanized mice expressing hTf. Immunological correlates and determinants of protection will be defined by broadly testing humoral and cellular immunity factors. Aim 3. Test for protective efficacy of Tbp-based vaccines in new humanized infection models. Optimized antigens, adjuvants, routes and schedules will be tested for protection in humanized mouse models of pelvic inflammatory disease, male urethritis and nasopharyngeal infection. Again, immunological correlates and determinants of protection in these new animal models of infection will be characterized. Aim 4. Evaluate rationally designed vaccines for cross protection in all models of infection. Optimized, rationally- designed vaccine formulations will be tested for protection against a broad group of Ngo strains, including antimicrobial resistant “superbug” strains. Immunological correlates of protection will be validated with these strains in all of the humanized mouse models of infection. These studies are significant since they may lead to the development of an efficacious vaccine against a recalcitrant pathogen that has developed resistance to existing therapeutic methods. These studies are innovative because they will employ structure-guided vaccine design to develop ligand-binding incompetent vaccine antigens, which are hypothesized exhibit enhanced immunogenicity compared to the wild-type proteins. Moreover, these antigens will be tested for protection in novel humanized mouse models of infection and immunological correlates of protection will be defined, closing a key gap in our understanding of immunity against Ngo.