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.

摘要 超过80%的哺乳动物抗体分泌细胞驻留在肠粘膜中并分泌抗体 免疫球蛋白A（IgA）同种型。IgA缺乏症在人类中很常见，并且容易导致各种疾病。 肠道病变，包括炎性肠病、乳糜泻和过敏。但尽管 几十年的研究，IgA的特异性仍然难以捉摸。IgA覆盖了一小部分肠道微生物群， IgA靶向的细菌的身份和所涉及的体液应答的类型仍然未知。 IgA也可以靶向饮食抗原，但目前还不清楚大多数IgA是否针对饮食抗原， 肠道微生物或其他肠道抗原。最后，由稳态IgA识别的特异性抗原 抗体尚未描述。在这里，我们提出了广泛的初步数据， 使用涉及细菌流式细胞术和16S rRNA的新方法通过IgA靶向肠道细菌 基因测序，称为IgA-Seq。我们进一步提出了一种克隆和表达重组 来自单个肠IgA产生细胞的单克隆抗体及其反应性的快速表征 针对微生物群使用IgA-Seq.最后，我们详细介绍了一个计划，以确定这些抗原的目标， 具有以下特定目的的抗体：1）表征肿瘤特异性抗体的起源和频率， B细胞; 2）确定单一IgA抗体的特异性。这些数据将被整合， 对肠道细菌和特定的细菌和/或饮食抗原的工作理解， 稳态IgA反应。对IgA特异性的理解将澄清关于其 难以捉摸的功能。此外，操纵IgA反应可能代表了一种有前途的治疗方法， 各种微生物群相关的病理，包括炎性肠病、乳糜泻、肥胖症， 糖尿病，但不能实现没有彻底了解其特异性。最后，我们的研究将 产生大量对共生微生物群特异性的单克隆抗体，这可能允许 操纵和表征健康或生态失调微生物群中定义的细菌亚群，并且可能具有 作为研究、诊断或治疗工具的应用。