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

项目摘要 沙眼衣原体（Ct）是世界范围内最常见的细菌性性传播感染， 女性的严重医疗并发症，包括盆腔炎、宫外孕，以及 不孕因此，迫切需要一种疫苗。成功开发疫苗的一个障碍是缺乏 全面了解对Ct感染的保护性免疫反应，包括 表位特异性抗体。这项奖学金提案的总体目标是精细地绘制抗体 在有急性Ct感染史的女性中的反应，确定Ct抗原的免疫显性表位， 研究Ct感染结果阳性（定义为无）的妇女之间的差异抗体应答 3个月随访时Ct再感染或未经抗生素治疗的Ct感染自发消退）和 女性谁经历Ct再感染，并确定这些功能和保护能力， 抗体反应。待检验的中心假设是，不同患者的抗体反应不同 那些有阳性Ct感染结果的人比那些经历Ct再感染的人，这些表位- 特异性抗体的粘附因子的Ct将发挥重要的作用，在保护（结合到Ct感染 细胞，中和，抗体介导的嗜中性粒细胞杀伤，以及在鼠模型中保护免受Ct攻击）。 长期目标是通过更好地了解保护性免疫反应， 最终得到有效的Ct疫苗以下具体目标将用于检验假设： 具体目标1：确定女性泌尿生殖道Ct感染的自然血清抗体反应。利用深度 序列偶联生物淘选是一种新技术，它使用少量的人血清来精细地定位 抗体反应在表位水平，我将阐明天然抗体反应Ct感染。这将 根据经验确定24个Ct抗原的免疫显性表位和B细胞表位。我还将定义 Ct感染阳性的女性与 在抗生素治疗后3个月内发生Ct再感染的患者。 具体目的2：研究Ct粘附因子表位特异性抗体的功能。抗体 将检测患者队列（SA 1）之间的免疫显性表位和差异抗体应答， 确定针对Ct感染的保护能力的功能。使用体外技术，我将确定 这些表位特异性抗体可以结合Ct，具有中和能力，并且可以在抗体中起作用， 介导的中性粒细胞Ct杀伤。我还将确定这些抗体是否可以防止Ct感染， 通过监测Ct感染、细菌脱落、Ct清除和上生殖道病理学，在鼠模型中进行。 总之，该提案将研究表位特异性抗体的特异性，功能和作用， 保护免受Ct感染，并有可能通过了解 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.