Characterization of neutralizing antitoxins and epitopes in Clostridium difficile patients

艰难梭菌患者中和抗毒素和表位的特征

• 批准号: 10319522
• 负责人: Hanping Feng
• 金额: $ 38.63万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-16 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10319522
• 关键词: Antibodies; Antibody Response; B-Lymphocytes; Binding; Biological Assay; Biological Markers; Cells; Characteristics; Clinical; Clostridium difficile; Data; Development; Diagnosis; Disease; Disease Outbreaks; Disease Outcome; Disease Progression; Enzyme-Linked Immunosorbent Assay; Epitopes; Financial cost; Frequencies; Future; Goals; Human; Immune; Immune response; Immunity; Immunodominant Epitopes; Immunoglobulin A; Immunoglobulin G; Immunoglobulin Isotypes; Individual; Infection; Kinetics; Knowledge; Lead; Maps; Mediating; Monoclonal Antibodies; Morbidity - disease rate; Outcome; Passive Immunotherapy; Patients; Prevention; Property; Recurrence; Serum; Severities; Severity of illness; Specificity; Testing; Therapeutic; Toxin; Vaccines; Virulence Factors; antitoxin; base; design; gut inflammation; individual patient; infection management; intestinal injury; method development; mortality; neutralizing antibody; novel; novel vaccines; outcome prediction; predictive marker; recurrent infection; response; tool

Abstract Intestinal injury and inflammation in Clostridium difficile infection (CDI), an increasing cause of morbidity, mortality and financial cost in the US, is mediated by two large clostridial toxins: TcdA & TcdB. Although antibodies against each toxin have been shown to be associated with protection, it is unclear what types of antibodies and their epitopes are responsible for effective immunity against CDI in patients. The goal of this project is to define the characteristics of a protective humoral immune response in CDI and the major neutralizing TcdA & TcdB epitopes. The hypothesis is that host antibodies directed against major neutralizing epitopes in TcdA & TcdB confer protection against CDI. To test this hypothesis, we will first validate our preliminary finding on neutralizing anti-TcdA/TcdB responses that correlate protection against severe CDI will also correlate protection against recurrence (Aim 1); subsequently we will characterize C. difficile toxin-specific B cell responses at clonal level and correlate these with CDI disease progression and recurrence (Aim 2); and finally we will clone neutralizing antibodies from individual B cells to obtain a representative panel of human protective monoclonal antibodies against the two toxins and characterize their binding epitopes and reactivity to a variety of toxins produced by major C. difficile endemic and outbreak strains (Aim 3). The completion of these specific aims can lead to the discovery of antibody biomarkers that predict outcomes of the most significant clinical issues in CDI management, including CDI occurrence, severity, and recurrence. Identification and characterization of protective antibodies may also facilitate the development of novel passive immunotherapy and vaccine approaches.

抽象的 艰难梭菌感染 (CDI) 引起的肠道损伤和炎症是发病率日益增加的原因， 在美国，死亡率和经济成本是由两种大型梭菌毒素介导的：TcdA 和 TcdB。虽然 针对每种毒素的抗体已被证明与保护相关，但尚不清楚哪些类型 抗体及其表位负责患者对 CDI 的有效免疫。此举的目标 该项目的目的是确定 CDI 中保护性体液免疫反应的特征以及主要 中和 TcdA 和 TcdB 表位。假设是宿主抗体针对主要中和作用 TcdA 和 TcdB 中的表位可提供针对 CDI 的保护。为了检验这个假设，我们首先要验证我们的 关于中和抗 TcdA/TcdB 反应的初步发现与严重 CDI 的保护相关 还将防止复发的保护联系起来（目标 1）；随后我们将表征艰难梭菌毒素特异性 克隆水平的 B 细胞反应并将其与 CDI 疾病进展和复发相关联（目标 2）；和 最后，我们将从单个 B 细胞中克隆中和抗体，以获得具有代表性的人类 B 细胞组。 针对两种毒素的保护性单克隆抗体并表征其结合表位和反应性 主要艰难梭菌地方性和暴发菌株产生的多种毒素（目标 3）。完成 这些具体目标可以导致抗体生物标志物的发现，这些生物标志物可以预测大多数患者的结果 CDI 管理中的重大临床问题，包括 CDI 的发生、严重程度和复发。 保护性抗体的鉴定和表征也可能促进新型被动抗体的开发 免疫疗法和疫苗方法。