B cell repertoires and function in food allergen multi-OIT

项目总结 食物过敏在美国越来越普遍，大约三分之一的患者患有 对多种食物的反应性。及时有效地治疗多种食物过敏是临床上尚未得到满足的需求 但指导选择最佳治疗策略的机制因素尚不清楚。 本项目旨在对人类B细胞和免疫球蛋白(Ig)有新的认识 多种食物过敏患者的反应及多变应原诱导的B细胞变化分析 口服免疫疗法(多OIT)单独或联合靶向IgE或IL-4/IL-13受体的生物制剂 组分IL-4Rα。我们将使用流式细胞术分离变应原特异性B细胞，重点是细胞特异性 对于牛奶、花生或腰果过敏原，与免疫球蛋白(Ig)基因的DNA深度测序配对 重排，以表征过敏患者的致病B细胞群，并确定 引起克隆群体、抗体同型表达、抗体体细胞突变和亲和力的变化 在成功的多个OIT治疗期间，在这些B细胞群中。我们会评估是否有B细胞 曲目功能，无论是在多OIT之前，还是在多OIT期间，预测参与者的反应并可以 被用来指导治疗。这些研究将在具有良好特征的多发性过敏症的样本上进行。 项目1中提议的试点、第二阶段多OIT临床试验的参与者以及来自适当的 特应性和健康对照受试者。我们将评估和比较B细胞和 牛奶、花生和腰果过敏原的特异性抗体及其对多种食物反应的变化 同样的人。在参与者的一个子集中，我们将研究血液和胃肠道活检样本中的B细胞，以 确定外周血B细胞监测在多大程度上准确反映患者的过敏性疾病状态 患者的胃肠道，以及多次OIT引起的变化。重要的是，我们还将分析 在多个卵巢移植期间针对α或IL-4R的单抗治疗，以确定这些 生物治疗影响多器官移植所致B细胞改变的性质和时间进程。我们还会另外 在我们的Poisted和MAPX OIT试验中对参与者进行B细胞的长期跟踪研究。 本项目的B细胞数据将与临床数据和实验数据结合并分析 来自项目1、3和4以及核心B的T细胞和嗜碱性粒细胞的数据，与数据分析合作 核心C，以实现与多种食物相关的免疫表型的全面评估 过敏性疾病，以及对多种药物的成功和持久的治疗反应。

PROJECT SUMMARY Food allergy is increasingly prevalent in the United States, and approximately one-third of patients have reactivity to multiple foods. There is an unmet clinical need to treat multi-food allergy in a timely and efficacious manner, but the mechanistic factors that should guide selection of an optimal treatment strategy are unclear. This project aims to obtain fundamental new understanding of human B cell and immunoglobulin (Ig) responses in patients allergic to multiple foods, and to analyze the B cell alterations induced by multi-allergen oral immunotherapy (multi-OIT) alone or in combination with biologics targeting IgE or the IL-4/IL-13 receptor component IL-4Rα. We will use flow cytometry isolation of allergen-specific B cells, focusing on cells specific for milk, peanut or cashew allergens, paired with DNA deep sequencing of immunoglobulin (Ig) gene rearrangements, to characterize pathogenic B cell populations in allergic patients, and to determine what changes in clonal populations, antibody isotype expression, antibody somatic mutation, and affinity are induced in these B cell populations during successful multi-OIT treatment. We will evaluate whether there are B cell repertoire features, either prior to multi-OIT, or during multi-OIT, that predict participants’ responses and could be used to guide therapy. The studies will be performed on specimens from well-characterized multi-allergic participants in the pilot, phase 2 multi-OIT clinical trial proposed in Project 1, as well as from appropriate atopic and healthy control subjects. We will evaluate and compare the molecular features of B cells and antibodies specific for milk, peanut and cashew allergens, and their alterations in response to multi-OIT, within the same people. In a subset of participants, we will study B cells in both blood and GI biopsy specimens, to determine to what extent peripheral blood B cell monitoring accurately reflects the allergic disease state in the GI tract of patients, and the changes induced by multi-OIT. Importantly, we will also analyze the effects of monoclonal antibody therapies targeting IgE or IL-4Rα during multi-OIT, to determine the extent to which these biologic therapies affect the nature and time course of B cell changes induced by multi-OIT. We will additionally perform long-term follow up studies of B cells in participants in our POISED and MAPX OIT trials. The B cell data from this Project will be combined and analyzed together with clinical data and experimental data from T cells and basophils from Projects 1, 3 and 4, and Core B, in collaboration with the Data Analysis Core C, to enable a comprehensive evaluation of immunological phenotypes associated with multi-food allergic disease, and with successful and durable therapeutic responses to multi-OIT.