Specificity of Intestinal Immunoglobulin A

肠道免疫球蛋白 A 的特异性

• 批准号: 9296031
• 负责人: ALBERT S. BENDELAC
• 金额: $ 48.94万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-15 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9296031
• 关键词: Address; Antibodies; Antigen Targeting; Antigens; Automobile Driving; B cell repertoire; B-Lymphocyte Subsets; B-Lymphocytes; Bacteria; Bone Marrow; Celiac Disease; Cell Compartmentation; Cell Lineage; Cells; Cloning; Communities; Data; Defect; Development; Diabetes Mellitus; Diagnostic; Diet; Environment; Epithelial Physiology; Flow Cytometry; Food Hypersensitivity; Frequencies; Gene Expression; Genomics; Homeostasis; Human; Hypersensitivity; Immune; Immunity; Immunoglobulin A; Immunoglobulin Somatic Hypermutation; Immunoglobulin-Secreting Cells; Individual; Inflammation; Inflammatory Bowel Diseases; Intestinal Mucosa; Intestines; Knowledge; Lactation; Lamina Propria; Mammary gland; Mass Spectrum Analysis; Mediating; Methods; Mission; Monoclonal Antibodies; Mutant Strains Mice; Nature; Obesity; Orphan; Pathology; Peripheral; Plasma Cells; Play; Polysaccharides; Predisposition; Process; Public Health; Recombinants; Research; Resolution; Role; Sampling; Shapes; Site; Specificity; Symbiosis; T-Lymphocyte; Therapeutic; United States National Institutes of Health; Work; base; cell motility; commensal microbes; enteric pathogen; gut microbiota; human disease; intestinal homeostasis; microbial; microbiota; monoclonal antibody production; novel; novel strategies; prevent; rRNA Genes; response; tool

ABSTRACT More than 80% of mammalian antibody-secreting cells reside in the intestinal mucosa and secrete antibodies of the immunoglobulin A (IgA) isotype. IgA deficiency is common in humans and predisposes toward various intestinal pathologies including inflammatory bowel disease, celiac disease, and allergy. However, despite decades of research, the specificity of IgA remains elusive. IgA coats a fraction of the intestinal microbiota, yet the identities of the bacteria targeted by IgA and the types of humoral responses involved remain unknown. IgA may also target dietary antigens, but it is unclear whether most IgA is directed against dietary antigens, commensal microbiota, or other intestinal antigens. Lastly, specific antigens recognized by homeostatic IgA antibodies have not been described. Here we present extensive preliminary data characterizing the commensal bacteria targeted by IgA using a novel method involving bacterial flow cytometry and 16S rRNA gene sequencing, termed IgA-Seq. We further present a method for cloning and expression of recombinant monoclonal antibodies from single intestinal IgA-producing cells and rapid characterization of their reactivity against microbiota using IgA-Seq. Finally, we detail a plan for determining the antigenic targets of these antibodies with the following specific aims: 1) To characterize the origin and frequency of commensal-specific B cells; and 2) To determine the specificities of single IgA antibodies. These data will be integrated to develop a working understanding of the commensal bacteria and specific bacterial and/or dietary antigens that drive homeostatic IgA responses. An understanding of the specificity of IgA will clarify hypotheses regarding its elusive function. Further, manipulation of the IgA response may represent a promising therapeutic approach to various microbiota-associated pathologies including inflammatory bowel disease, celiac disease, obesity, and diabetes, but cannot be achieved without a thorough understanding of its specificity. Lastly, our studies will generate a large panel of monoclonal antibodies specific for commensal microbiota that may allow manipulation and characterization of defined bacterial subsets in healthy or dysbiotic microbiota and may have applications as research, diagnostic, or therapeutic tools.

抽象的 超过80%的哺乳动物抗体分泌细胞驻留在肠粘膜并分泌抗体 免疫球蛋白 A (IgA) 同种型。 IgA 缺乏症在人类中很常见，容易导致各种疾病 肠道病理包括炎症性肠病、乳糜泻和过敏。然而，尽管 经过数十年的研究，IgA 的特异性仍然难以捉摸。 IgA 覆盖了肠道微生物群的一小部分，但 IgA 所针对的细菌的身份以及所涉及的体液反应类型仍然未知。 IgA 也可能针对饮食抗原，但目前尚不清楚大多数 IgA 是否针对饮食抗原， 共生微生物群或其他肠道抗原。最后，稳态 IgA 识别的特定抗原 抗体尚未被描述。在这里，我们提供了广泛的初步数据来表征 使用细菌流式细胞术和 16S rRNA 等新方法研究 IgA 靶向的共生细菌 基因测序，称为 IgA-Seq。我们进一步提出了重组蛋白的克隆和表达方法 来自单个肠道 IgA 产生细胞的单克隆抗体及其反应性的快速表征 使用 IgA-Seq 对抗微生物群。最后，我们详细介绍了确定这些抗原靶标的计划 具有以下特定目标的抗体：1）表征共生特异性的起源和频率 B细胞； 2) 确定单一 IgA 抗体的特异性。这些数据将被整合以开发 对驱动的共生细菌和特定细菌和/或饮食抗原的有效理解 稳态 IgA 反应。了解 IgA 的特异性将澄清有关其的假设 难以捉摸的功能。此外，操纵 IgA 反应可能代表一种有前途的治疗方法 各种与微生物相关的病症，包括炎症性肠病、乳糜泻、肥胖症和 糖尿病，但如果不彻底了解其特殊性，就无法实现这一目标。最后，我们的研究将 产生大量针对共生微生物群的单克隆抗体，这可能允许 对健康或失调微生物群中确定的细菌亚群进行操作和表征，并可能具有 作为研究、诊断或治疗工具的应用。