High-dimensional profiling of B cells in food allergy

食物过敏中 B 细胞的高维分析

• 批准号: 9121279
• 负责人: Loren D Erickson
• 金额: $ 24.19万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-15 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9121279
• 关键词: Adult; Affect; Allergens; Allergic; Allergic Disease; Allergic Reaction; American; Anaphylaxis; Animals; Antibodies; Antigens; B-Cell Activation; B-Lymphocyte Subsets; B-Lymphocytes; Binding; Bioinformatics; Biological Markers; Bite; Blood specimen; Blood typing procedure; Breathing; Carbohydrates; Cells; Child; Clinical; Clinical Data; Consumption; Cytometry; Development; Disease; Eating; Event; Excision; Flow Cytometry; Food; Food Hypersensitivity; Foundations; Frequencies; Galactose; Gastrointestinal tract structure; Generations; Goals; Heterogeneity; Human; Hypersensitivity; IgE; Immune; Immunoglobulin Class Switching; In Vitro; Individual; Invaded; Knowledge; Life; Longevity; Mammals; Measures; Meat; Mediating; Mediator of activation protein; Memory; Memory B-Lymphocyte; Methods; Modeling; Modification; Molecular; Molecular Structure; Pathway interactions; Patients; Peripheral; Phenotype; Plasma Cells; Population; Population Heterogeneity; Production; Proteins; Reaction; Research; Resolution; Risk Management; Role; Sampling; Sampling Studies; Serum; Signal Transduction; Source; Staging; Structure of germinal center of lymph node; System; T-Lymphocyte; Thinking; Ticks; Time; Vaccines; Work; base; blood group; cohort; design; gastrointestinal; high risk; improved outcome; novel; novel therapeutic intervention; pathogen; pediatric patients; peripheral blood; programs; protein biomarkers; public health relevance; red meat consumption; response; stem; targeted treatment; tool

 DESCRIPTION (provided by applicant): Food allergies affect 15 million Americans and carry a high risk of life-threatening allergic reactions. Therefore, establishing its cause is critical to ong-term risk management. The production of allergen-specific IgE antibodies is a key mediator of these disorders. However, the B cell populations that are the source of IgE and how IgE production is controlled remain unclear. The overall goal of this project is to define the heterogeneity of human B cells that produce allergen-specific IgE using food allergy as a model. The basis for this project stems from initial observations by Platts-Mills and Commins that a novel form of food allergy related to IgE antibodies specific for galactose-α-1,3-galactose (alpha gal) results in delayed anaphylaxis in adult and pediatric patients after consumption of red meat. Alpha-gal is a blood group carbohydrate of nonprimate mammals and therefore is present in meat of animals that carry this carbohydrate. Remarkably, most of these patients had previously tolerated meat for years, suggesting that sensitization to alpha-gal occurred later in life leading to the production of alpha-gal specific IgE. The primary cause of these IgE antibodies is bites from ticks, which contain alpha-gal in the gastrointestinal tract. Thus, alpha-gal within ticks explains the relationship between tick exposure and sensitization to alpha-gal, with development of red meat allergy as a secondary event. In preliminary work, we assessed in vitro B cell responses to tick extract and found increased frequencies of memory B cells and plasma cells from PBMCs of allergic subjects but not healthy controls. We further observed greater activation and proliferation of class-switched B cells expressing markers previously associated with a memory phenotype. Based on these observations, we hypothesize that the alpha-gal IgE in patients with red meat allergy emerges from a memory B cell subset that responds to alpha-gal exposure via tick bites and after eating red meat. However, resolving the heterogeneity of peripheral B cells, including memory B cells, has been limited using standard cell analysis methods such as flow cytometry. We have applied mass cytometry by time-of-flight (CyTOF), which supports 40 markers in a single sample, for high- dimensional immune profiling of peripheral B cells from healthy donors and identified heterogeneous subsets within memory B cells that was consistent across individuals. This suggests that it may be possible to detect allergy-related changes in B cell populations and identify cellular sources of IgE in human peripheral blood samples using CyTOF. In this proposal we will build on these new findings to define the B cell compartment in red meat allergy subjects and determine the relationships between B cell populations and clinical data, and to determine the requirements for an alpha-gal specific IgE response following allergen exposure. Collectively, we expect these studies to yield new information for understanding the immune status of distinct B cell subsets in IgE-mediated food allergy, and better define immune signatures that inform global and allergen-specific B cell responses.

 描述（由申请人提供）：食物过敏影响着 1500 万美国人，并且具有危及生命的过敏反应的高风险，因此，确定其原因对于长期风险管理至关重要，过敏原特异性 IgE 抗体的产生是关键。然而，作为 IgE 来源的 B 细胞群以及如何控制 IgE 的产生仍不清楚，该项目的总体目标是确定产生过敏原特异性的人类 B 细胞的异质性。使用食物过敏作为模型的 IgE 源于 Platts-Mills 和 Commins 的初步观察，即一种与半乳糖-α-1,3-半乳糖（α）特异性 IgE 抗体相关的新型食物过敏。 α-gal）会导致成人和儿童患者在食用红肉后出现迟发性过敏反应。α-gal是非灵长类哺乳动物的一种血型碳水化合物，因此存在于携带这种碳水化合物的动物的肉中。值得注意的是，大多数这些患者以前都能够耐受。多年食用肉类，表明对 α-gal 的过敏发生在晚年，导致 这些 IgE 抗体的主要原因是蜱虫叮咬，蜱虫的胃肠道中含有 α-gal，因此，蜱虫体内的 α-gal 解释了蜱虫接触与对 α-gal 过敏之间的关系。 gal，红肉过敏是继发事件。在初步工作中，我们评估了体外 B 细胞对蜱提取物的反应，发现过敏受试者（但健康受试者）的 PBMC 中记忆 B 细胞和浆细胞的频率增加。我们进一步观察到表达先前与记忆表型相关的标记物的类别转换 B 细胞的更大激活和增殖。基于这些观察，我们发现红肉过敏患者中的 α-gal IgE 来自记忆 B 细胞亚群。然而，使用流式细胞术等标准细胞分析方法来解决外周 B 细胞（包括记忆 B 细胞）的异质性受到限制。飞行时间 (CyTOF) 支持单个样本中的 40 个标记，可对健康供体的外周 B 细胞进行高维免疫分析，并识别记忆 B 细胞内的异质子集，这些子集在个体之间是一致的。可以使用 CyTOF 检测 B 细胞群中与过敏相关的变化并识别人类外周血样本中 IgE 的细胞来源。在本提案中，我们将基于这些新发现来定义红肉过敏受试者中的 B 细胞区室和确定 B 细胞群与临床数据之间的关系，并确定过敏原暴露后 α-gal 特异性 IgE 反应的要求。总的来说，我们期望这些研究能够产生新的信息，以了解 IgE 中不同 B 细胞亚群的免疫状态。介导的食物过敏，并更好地定义免疫特征，以告知整体和过敏原特异性 B 细胞反应。