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（由适用提供）：食物过敏会影响1500万美国人，并具有威胁生命的过敏反应的高风险。因此，建立其原因对于在任期风险管理中至关重要。过敏原特异性IgE抗体的产生是这些疾病的关键介体。但是，作为IgE来源的B细胞群体以及如何控制IgE的生产尚不清楚。该项目的总体目标是定义使用食物过敏作为模型产生过敏原特异性IgE的人B细胞的异质性。从Platts-Mills和Commins进行最初观察到的该项目步骤的基础，即一种与肠乳糖-α-1,3-半乳糖（Alpha）相关的新型食物过敏形式 GAL）在食用红肉后导致成人和小儿患者的过敏反应延迟。 α-gal是一种非哺乳动物的血液组碳水化合物，因此在携带这种碳水化合物的动物的肉中呈现。值得注意的是，这些患者大多数以前已经耐受了多年的肉类耐受性，这表明对α-gal的敏感性发生在较晚的生活中 生产α-gal特异性IgE。这些IgE抗体的主要原因是滴答物中的位，滴答物中含有alpha-gal。这是tick中的alpha-gal解释了tick虫暴露与对α-gal的敏感性之间的关系，并发展了红肉过敏作为次要事件之间的关系。在初步工作中，我们评估了tick提取物的体外B细胞反应，发现记忆B细胞和浆细胞的频率增加了过敏受试者而不是健康对照的PBMC。我们进一步观察到表达与记忆表型相关的类别的B细胞的更大激活和增殖。基于这些观察结果，我们假设红肉过敏患者的α-gal IgE是由记忆B细胞子群出现的，该子群通过tick叮咬和吃红肉后对α-gal暴露有反应。然而，使用标准细胞分析方法（例如流式细胞术）限制了解决周围B细胞（包括记忆B细胞）的异质性，包括记忆B细胞。我们已经通过飞行时间（CytoF）应用了质量细胞仪，该量子仪支持单个样品中的40个标记，以从健康供体的外周B细胞对外周B细胞的高维度分析，并在记忆B细胞中鉴定出异质的子集，这些子群在各个个体之间是一致的。这表明可以使用Cytof检测B细胞群体中与过敏相关的变化，并在人外周血样品中鉴定IgE的细胞来源。在此提案中，我们将基于这些新发现，以定义红肉过敏受试者的B细胞室，并确定B细胞种群和临床数据之间的关系，并确定过敏原暴露后对α-GAL特异性IgE响应的要求。总的来说，我们希望这些研究能够产生新的信息，以了解IgE介导的食物过敏中不同B细胞子集的免疫状态，并更好地定义了为全球和过敏蛋白特异性B细胞反应提供信息的免疫特征。