Effects of neonatal microbial exposure on anti-polysaccharide B cell development

新生儿微生物暴露对抗多糖 B 细胞发育的影响

• 批准号: 9755324
• 负责人: John Franklin Kearney
• 金额: $ 37.13万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9755324
• 关键词: 2 year old; Adenoidal structure; Adult; Age; Allergens; Allergic Disease; Antibodies; Antibody Repertoire; Antibody Response; Antibody Specificity; Antigenic Specificity; Antigens; Autoantigens; Autoimmune Diabetes; Autoimmune Diseases; B cell repertoire; B-Cell Development; B-Lymphocyte Epitopes; B-Lymphocytes; Bacteria; Bacterial Infections; Bacterial Polysaccharides; Binding; Biochemical; Blood; Bone Marrow; Cell Compartmentation; Cell Wall; Cell surface; Child; Chimera organism; Clonal Expansion; Clone Cells; Development; Dextrans; Environment; Environmental Risk Factor; Epitopes; Evolution; Exposure to; Frequencies; Funding; Germ-Free; Glucosamine; Gnotobiotic; Goals; Heavy-Chain Immunoglobulins; Heterogeneity; Human; Immune; Immunization; Immunoglobulin Genes; Immunoglobulin M; Individual; Infant; Infection; Inflammatory Response; Kinetics; Lamina Propria; Licensing; Life; Lymphoid; Lymphopoiesis; Mammals; Manuscripts; Mediating; Modeling; Mouse Strains; Mus; Nature; Neonatal; Organism; Outcome Study; Pathogenicity; Phenotype; Phospholipids; Phosphorylcholine; Polysaccharides; Predisposition; Preparation; Probiotics; Process; Property; Receptors, Antigen, B-Cell; Recombinant Antibody; Recombinants; Risk; Role; Serum; Shapes; Signal Transduction; Specificity; Streptococcus pneumoniae; Streptococcus pyogenes; System; T-Independent Antigens; Testing; Therapeutic Intervention; Time; To autoantigen; Tonsil; Transgenic Mice; Transgenic Organisms; Umbilical Cord Blood; Vaccination; Vaccines; age group; allergic airway disease; autoreactive B cell; bacterial resistance; base; commensal microbes; disorder prevention; experience; gut colonization; gut microbiota; insight; microbial; microbial colonization; microbiota; microorganism antigen; neonatal exposure; neonate; novel; novel therapeutics; pathogen; pathogenic bacteria; peripheral blood; receptor; reconstitution; response

ABSTRACT Innate-like B cell-derived natural antibodies (NAbs) against T-independent polysaccharide (PS) and phospholipid epitopes are universally present in mammals and serve important roles in the protection against many bacterial pathogens. However robust antibody responses against PS antigens following infection or immunization are absent in neonates. We previously showed that neonatal exposure to PS and phospholipid antigens by immunization or natural colonization with the microbiota, influences the clonal distribution of antigen-specific innate-like B cells leading to quantitative increases in natural antibody (Nab) levels. These effects impact adult susceptibility to infection, and immune-responsiveness to allergens and auto antigens bearing similar B cell epitopes. Although the microbiota impacts the development of other lymphoid lineages its role in the development of the adult innate-like B cell and NAb repertoires is largely unexplored. Our hypothesis is that in addition to the well-described selection processes that occur during B cell development, the accessibility to autologous antigens and exogenous commensal-derived epitopes combine during neonatal development to shape the natural repertoire. The goal of these proposed studies is to elucidate mechanisms of exogenous antigen-directed development of the innate-like B cell repertoire using three model B cell antigen- specificities that represent epitopes for relevant pathogenic and commensal organisms with a spectrum of auto antigenic potential: phosphorylcholine (PC), N-acetyl-D-glucosamine (GlcNAc), and dextran (DEX). In Aim 1 of these studies wild-type gnotobiotic mice will be colonized with defined microbiota to assess the contribution of exogenous antigen signaling on clonal B cell development and formation of the NAb repertoire. Bone marrow chimera systems, composed of antigen-specific immunoglobulin (Ig) heavy chain-transgenic mouse strains, and lineage tracking will enable assessment of endogenous and exogenous antigen signaling on B lymphocyte selection and receptor editing processes. In Aim 2 we will analyze the frequency, cell surface phenotype, subset and isotype distribution as well as immunoglobulin gene usage of human B cells specific for these antigens. Examination of B cells isolated from cord blood, tonsils/adenoids, and peripheral blood B cells of donors of different ages will provide novel insight into the role of antigen experience in the formation of innate- like B cell repertoire diversity within and across individuals. Antigen-specific Ig genes will be cloned and expressed as recombinant antibody to determine effects of antigen-driven maturation on functions of these human antibodies. Collectively, these studies will define the microbial influences on NAb development in mice, determine developmental kinetics of human NAb development, and compare and contrast the NAb repertoire development between both species. This insight into the human infant responses to infection and colonization will advance our long-term goal of developing effective neonatal vaccine strategies and interventional therapies that provide protection from infectious pathogens and allergic and autoimmune diseases.

抽象的 对T独立多糖（PS）和 磷脂表位普遍存在哺乳动物中，并在保护中起重要作用 许多细菌病原体。但是，感染后针对PS抗原的鲁棒抗体反应或 新生儿没有免疫。我们先前表明新生儿暴露于PS和磷脂 通过微生物群免疫或自然定殖抗原，会影响克隆分布 抗原特异性的先天B细胞导致天然抗体（NAB）水平的定量增加。这些 影响影响成人对感染的敏感性，以及对过敏原和自动抗原的免疫反应性 带有相似的B细胞表位。尽管微生物群会影响其他淋巴谱系的发展 在很大程度上尚未探索成人先天性B细胞和NAB曲目的发展中的作用。我们的 假设是，除了在B细胞发育过程中发生的描述良好的选择过程外， 自体抗原和外源分子衍生的表位的可及性在新生儿结合 开发以塑造自然曲目。这些提出的研究的目的是阐明 使用三种B细胞抗原 - 代表与自动谱相关的病原和共生生物的表位的特异性 抗原势：磷酸胆碱（PC），N-乙酰基-D-葡萄糖胺（GLCNAC）和右旋烷（DEX）。在目标1中 这些研究将用定义的微生物群定植野生型gnotobirotic小鼠，以评估 克隆B细胞发育和NAB曲目形成的外源抗原信号传导。骨髓 嵌合体系统，由抗原特异性免疫球蛋白（IG）重链转基因小鼠菌株组成 谱系跟踪将能够评估B淋巴细胞上内源性和外源性抗原信号传导 选择和受体编辑过程。在AIM 2中，我们将分析频率，细胞表面表型， 特有的人类B细胞的子集和同型分布以及免疫球蛋白基因的使用 抗原。检查从脐带血，扁桃体/腺样体和外周血B细胞中分离出的B细胞 不同年龄的捐助者将提供对抗原经验在与先天形成形成的作用的新颖见解。 像B细胞曲目内部和跨个体的多样性一样。抗原特异性Ig基因将被克隆，并 表示为重组抗体，以确定抗原驱动成熟对这些功能的作用的影响 人类抗体。总的来说，这些研究将定义对小鼠NAB发育的微生物影响， 确定人类NAB发展的发展动力学，并比较和对比NAB曲目 这两个物种之间的发展。对人类婴儿对感染和殖民的反应的洞察力 将促进我们制定有效的新生儿疫苗策略和介入疗法的长期目标 可保护免受感染性病原体以及过敏和自身免疫性疾病的保护。