Functional Antibody Repertoire Against S. aureus Leukocidins after Invasive Human Infection

人类侵袭性感染后针对金黄色葡萄球菌杀白细胞素的功能性抗体库

• 批准号: 10326846
• 负责人: Isaac P Thomsen
• 金额: $ 70.33万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-16 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10326846
• 关键词: Active Immunotherapy; Activities of Daily Living; Acute; Address; Affinity; Age; Animal Model; Antibiotic Resistance; Antibodies; Antibody Diversity; Antibody Repertoire; Antibody Response; Antigens; Binding Sites; Biological Assay; Blood; Cellular Immunity; Child; Childhood; Clinical; Complement; Deposition; Disease; Enrollment; Evaluation; Fc domain; Genus staphylococcus; Goals; Human; Humoral Immunities; ITGAM gene; Immune Evasion; Immune response; Immune system; In Vitro; Infection; Intervention; Investigation; Knowledge; Laboratories; Leucocidin; Mediating; Modeling; Monoclonal Antibodies; Organism; Passive Immunotherapy; Pediatric Hospitals; Phagocytes; Phagocytosis; Prospective cohort; Research Personnel; Role; Sepsis; Series; Specificity; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus aureus infection; Targeted Toxins; Testing; Time; Tissues; Toxicity Tests; Toxin; Vaccines; Validation; Virulence; Virulence Factors; Whole Blood; Work; antitoxin; base; cohort; design; efficacy testing; experience; human disease; human monoclonal antibodies; leukotoxin; mouse model; neutralizing antibody; neutralizing monoclonal antibodies; new therapeutic target; novel; novel therapeutic intervention; pathogen; pathogenic bacteria; pre-clinical; preclinical study; prospective; response; tertiary care; therapeutic candidate; therapeutic target; vaccine candidate

PROJECT SUMMARY / ABSTRACT Staphylococcus aureus is now the most common invasive bacterial pathogen in children in the US, and antibiotic resistance rates continue to increase. Novel targets and approaches are needed if a safe and effective S. aureus vaccine is to become a reality. Optimal targets of intervention against S. aureus, a highly human-specific pathogen, may be identified most effectively by defining the antigens that contribute to invasive human infections. LukAB, a secreted leukotoxin, is produced by S. aureus in the setting of invasive human disease and is essential for immune evasion by the pathogen in a variety of models. We have purified a series of potently neutralizing human monoclonal antibodies (mAbs) targeting LukAB, which have broad neutralizing capacity, distinct binding sites and mechanisms of activity, and efficacy in a murine model of sepsis. The overall goals of this proposal are twofold: first, to test the hypothesis that key aspects of the human anti-leukocidin adaptive response include both mechanisms of toxin neutralization and the function of non-neutralizing antibodies targeting these toxins; second, to test the hypothesis that a selected combination of mAbs with distinct functions will most potently inhibit toxin-mediated staphylococcal immune evasion. Careful validation of the anti-leukocidin antibody response in rigorous models will allow for the evaluation of human mAbs as candidate agents of intervention against S. aureus. The proposed studies will define the diversity of the naturally occurring antibody repertoire to S. aureus leukocidins following natural human infection, given their importance in virulence and promise as targets of intervention. This will be accomplished by: 1) Characterizing the diversity and functional capacity of naturally occurring human antibodies targeting the staphylococcal leukocidins following invasive pediatric infection; 2) Elucidating the role of non-neutralizing antibodies specific to S. aureus leukocidins, including antibody-dependent complement deposition and phagocytosis; and 3) Determining the critical components of the anti-leukocidin adaptive response against S. aureus in human blood. We will leverage our existing workflow for the purification and characterization of neutralizing mAbs from prospectively enrolled children with invasive and non-invasive S. aureus infections at a major tertiary care children’s hospital. A panel of human mAbs will be created to allow the investigation of diverse mechanisms of neutralization, cross-toxin activity, and other important functions. The proposed aims will define, for the first time, the breadth of mechanisms by which the human host response targets and neutralizes S. aureus leukocidins during invasive human disease. Together these studies address a critical need for novel anti-S. aureus strategies. This work is designed to produce rationally selected candidates for anti-staphylococcal interventions based on our knowledge of important antigens expressed during human disease, obtained from children with S. aureus infections, to be tested for efficacy in humanized animal models in immediately subsequent work.

项目摘要 /摘要 金黄色葡萄球菌现在是美国儿童中最常见的浸润性细菌病原体， 抗生素抗性率继续增加。如果安全和安全，需要新颖的目标和方法 有效的金黄色葡萄球菌疫苗将成为现实。针对金黄色葡萄球菌的干预措施的最佳目标，高度 可以通过定义有助于侵入性的抗原来最有效地鉴定人类特异性病原体 人类感染。卢卡布（Lukab）是一种分泌的白细胞毒素 疾病，对于多种模型中的病原体免疫进化至关重要。我们已经纯化了一个系列 靶向卢卡布的潜在中和人单克隆抗体（mAb）的中和 败血症鼠模型中的能力，独特的结合位点和活性的机制以及效率。 该提案的总体目标是双重的：首先，检验人类关键方面的假设 抗白细胞素自适应反应既包括毒素神经化的机制，又包括 靶向这些毒素的非中和抗体；其次，要检验选择的假设 具有不同功能的mAb的组合最有可能抑制毒素介导的葡萄球菌 免疫进化。在严格模型中仔细验证抗白细胞素抗体反应将允许 评估人单元单击作为对金黄色葡萄球菌干预的候选药物的评估。提出的研究 将定义自然后的天然抗体曲目的自然抗体库的多样性 人类感染，鉴于它们在病毒中的重要性和作为干预靶标的承诺。这将是 通过：1）表征自然发生的人的多样性和功能能力 侵入性小儿感染后针对葡萄球菌白细胞素的抗体； 2）阐明角色 对金黄色葡萄球菌特异性抗体的非中和化抗体，包括抗体依赖性完成 沉积和吞噬作用； 3）确定抗白细胞素自适应的关键成分 对人类血液中的金黄色葡萄球菌的反应。我们将利用现有的工作流程进行净化，并 来自前瞻性入学儿童具有侵入性和非侵入性的儿童的中和MAB的表征。 大三级护理儿童医院的金黄色感染。将创建一个人物板，以允许 中和，跨毒素活性和其他重要功能的潜水机制的投资。 提出的目标将首次定义人类宿主反应的机制广度 在侵入性人类疾病期间，靶标和中和白细胞蛋白链球菌。这些研究共同解决了 对新型抗S的关键需求。金黄色策略。这项工作旨在合理选择 基于我们对表达的重要抗原的知识，抗稳定球菌干预措施的候选者 在人类疾病期间，从金黄色葡萄球菌感染的儿童获得，以人性化的效率进行测试 动物模型在随后的工作中。