Defining Chlamydia trachomatis adhesion factor epitope-specific antibody responses, functionality, and roles in protection against urogenital infection

项目总结 沙眼衣原体(Ct)是全世界最常见的细菌性性传播感染，可引起 妇女的严重医疗并发症，包括盆腔炎、宫外孕和 不孕不育。因此，迫切需要一种疫苗。疫苗研发成功的一个障碍是缺乏 全面了解沙眼衣原体感染的保护性免疫反应，包括 表位特异性抗体。这项团契计划的总体目标是精细地绘制抗体图谱。 有急性沙眼衣原体感染史的妇女的反应，确定沙眼衣原体抗原的免疫优势表位， 研究CT感染结果为阳性(定义为NO)的妇女之间的抗体反应差异 3个月后CT再次感染或CT感染在未经抗生素治疗的情况下自发消失)和 经历沙眼衣原体再感染的女性，并确定这些病毒的功能和保护能力 抗体反应。需要检验的中心假设是，不同患者的抗体反应不同。 与经历过CT再感染的患者相比，CT感染结果呈阳性的患者，以及这些表位- 针对沙眼衣原体黏附因子的特异性抗体将发挥重要的保护作用(结合沙眼衣原体感染 在小鼠模型中，细胞、中和、抗体介导的中性粒细胞杀伤以及对CT挑战的保护)。 长期目标是通过更好地了解保护性免疫反应来为疫苗设计提供信息， 最终形成了一种有效的CT疫苗。以下具体目标将被用来检验这一假设： 具体目的1：明确女性泌尿生殖道沙眼衣原体感染的自然血清抗体反应。利用深度 序列耦合生物扫描，一种新的技术，使用少量的人类血清来精细地映射 抗体反应在表位水平上，我将阐明天然抗体对CT感染的反应。这将是 经验性地确定24个Ct抗原的免疫优势表位和B细胞表位。我还将定义 与CT感染结果阳性的女性相比，女性之间的抗体反应不同 那些在抗生素治疗后3个月内经历了CT再次感染的患者。 特异性目的2：研究CT黏附因子表位特异性抗体的功能。抗病毒抗体 将测试患者队列之间的免疫优势表位和差异抗体反应(SA1) 确定对CT感染的保护能力的功能。使用体外技术，我将确定是否 这些表位特异性抗体可与Ct结合，具有中和能力，并可作用于抗体- 介导的中性粒细胞CT杀伤。我还将确定这些抗体是否可以预防CT感染 通过监测沙眼衣原体感染、细菌脱落、沙眼衣原体清除和上生殖道病理建立小鼠模型。 总之，这项建议将研究表位特异性抗体的特异性、功能性和作用。 预防CT感染，并有可能通过了解以下方面显著推进CT领域 保护性免疫反应并为未来的疫苗设计提供信息。

PROJECT SUMMARY Chlamydia trachomatis (Ct) is the most common bacterial sexually transmitted infection worldwide and causes serious medical complications in women, including pelvic inflammatory disease, ectopic pregnancy, and infertility. Therefore, a vaccine is urgently needed. One obstacle to successful vaccine development is a lack of a comprehensive understanding of the protective immune response to Ct infection, including the role of epitope-specific antibodies. The overall objective of this fellowship proposal is to finely map the antibody response in women with an acute history of Ct infection, determine immunodominant epitopes of Ct antigens, investigate differential antibody responses between women with a positive Ct infection outcome (defined as no Ct reinfection at 3-months follow-up or spontaneous resolution of Ct infection without antibiotic treatment) and women who experience Ct reinfection, and determine the functionality and protective capacity of these antibody responses. The central hypothesis to be tested is that antibody responses will differ between patients who had a positive Ct infection outcome than those who experienced a reinfection of Ct and that these epitope- specific antibodies to adhesion factors of Ct will play an important role in protection (binding to Ct-infected cells, neutralization, antibody-mediated neutrophil killing, and protection from a Ct challenge in murine models). The long-term goal is to inform vaccine design through better understanding of protective immune responses, culminating in an effective Ct vaccine. The following specific aims will be used to test the hypothesis: Specific Aim 1: Define the natural serum antibody response to urogenital Ct infection in women. Utilizing Deep Sequence-Coupled Biopanning, a novel technology that uses a small amount of human sera to finely map the antibody response at an epitope-level, I will elucidate the natural antibody response to Ct infection. This will empirically determine immunodominant epitopes and B cell epitopes to 24 Ct antigens. I will also define differential antibody responses between women who experienced a positive Ct infection outcome compared to those who experienced a Ct reinfection within 3-months of antibiotic treatment. Specific Aim 2: Investigate Ct adhesion factor epitope-specific antibody functions. Antibodies to immunodominant epitopes and differential antibody response between patient cohorts (SA1) will be tested for functionality to determine protective capacity against Ct infection. Using in vitro techniques, I will determine if these epitope-specific antibodies can bind to Ct, have neutralizing capacity, and can function in antibody- mediated neutrophil Ct killing. I will also determine if these antibodies can protect against a Ct infection in a murine model by monitoring Ct infection, bacterial shedding, Ct clearance, and upper genital tract pathology. Together, this proposal will investigate the specificity, functionality, and role of epitope-specific antibodies in protection against Ct infection and has the potential to significantly advance the Ct field by understanding protective immune responses and informing future vaccine design.