Effects of IgE Blockade on T Cells in Food Allergy

免疫球蛋白E阻断对食物过敏T细胞的影响 食物过敏可导致近乎致命或致命的过敏反应。大约30%的食物过敏症患者 多发性食物过敏。尽管许多研究评估了口服免疫疗法(Oit)对 单一食品，评估OIT对多种食品(多OIT)的研究由于有效性和安全性而受到限制 担忧。多食物过敏患者可从治疗和奥马珠单抗(抗IgE阻断)中受益 治疗)有可能降低他们患上IgE介导的过敏反应的风险。一些团体，包括我们在内，已经 单一变应原OIT引起的重要免疫表型和功能生物标志物改变 在T细胞亚群中。这些报告的显著发现表明：在数量和功能上的增加 调节性T细胞(Treg)；辅助性T细胞(Th2)重新编程为辅助性T细胞1(Th1)亚型；以及 过敏原特异的Th2细胞。识别T细胞免疫标志物在多发性骨髓瘤发病过程中的变化具有重要意义 提供给多个过敏个体跟踪脱敏，与常规抗原(Ag)缺乏临床反应性 暴露，与持续性无反应不同，在这种情况下，患者表现出长期的和可能的 与持续的银暴露无关的对银的反应性的永久性丧失。因此，我们有 在一组多食物过敏参与者中进行了一项随机、对照的2期研究(多个 免疫疗法测试耐受性和Xolair，ClinicalTrials.gov标识：NCT02626611，n=70参与者)： 外周血单核细胞和血浆样本在整个过程中收集和储存 学习。我们建议在这个项目中使用这些样本和两组匹配的对照。 我们的主要假设是，多个OIT会导致Th2功能的显著下调及其伴随 Th1和Treg功能增强，这些变化将与持续性 反应迟钝，在较小程度上是脱敏。为了检验这一假设，我们建议：(目标1) 总的和特定的过敏原诱导的免疫表型和功能变化特征 多过敏研究参与者中的T细胞群；(目标2)使用基于MHC II类多聚体的方法进行分类 过敏原特异的单个细胞，并进行靶向RNA-Seq以研究其分子特征和 单细胞分辨率的克隆祖先；和(目标3)量化表观遗传变化(即CpG甲基化 在关键基因(即FOXP3、IL4、IFNG、IL10)中)，以评估甲基化与 由OIT引起的脱敏和持续性无反应。 这项对T细胞表型、功能和表观遗传学的研究结果将使我们能够：识别哪一种 这些免疫特征将是最有用的标志，多Oit诱导的脱敏和持续 无反应性；确定与这些不同的临床症状相关的T细胞的变化模式 多个OIT的结果；并确定如何通过添加 将奥马珠单抗应用于多OIT方案。

Project Summary: Effects of IgE Blockade on T Cells in Food Allergy Food allergies can lead to near-fatal or fatal anaphylaxis. Approximately 30% of food allergic individuals have multiple food allergies. Although many studies have evaluated the efficacy of oral immunotherapy (OIT) for single foods, studies evaluating OIT to multiple foods (multi-OIT) have been limited due to efficacy and safety concerns. Multifood allergic individuals could benefit from treatment, and omalizumab (anti-IgE blockade therapy) potentially mitigates their risk for IgE-mediated allergic reactions. A few groups, including ours, have demonstrated important immunophenotypic and functional biomarker changes induced by single-allergen OIT in T cell subsets. The salient findings from these reports show: increases in the numbers and function of regulatory T cells (Treg); reprogramming of T helper 2 cells (Th2) to the T helper 1 (Th1) subtype; and anergy in allergen-specific Th2 cells. It is of great interest to identify T cell immune biomarker changes while multi-OIT is given to multi-allergic individuals to track desensitization, a lack of clinical reactivity with regular antigen (Ag) exposure, as distinct from sustained unresponsiveness, in which the patient exhibits a long-term and perhaps permanent loss of reactivity to Ag that is independent of continued Ag exposure. Therefore, we have performed a randomized, controlled, phase 2 study in a cohort of multifood allergic participants (Multi Immunotherapy to Test Tolerance and Xolair, ClinicalTrials.gov Identifier: NCT02626611, n=70 participants): peripheral blood mononuclear cells and plasma samples were collected and stored throughout the duration of study. We propose to use these samples and two sets of matched controls for this project. Our main hypothesis is that multi-OIT results in marked downmodulation of Th2 function and concomitant enhancement in Th1 and Treg function, and that these changes will be associated with sustained unresponsiveness and, to a lesser extent, desensitization. To test this hypothesis, we propose to: (Aim 1) Characterize the immunophenotypic and functional changes induced by multi-OIT in total and allergen-specific T cell populations in multi-allergic study participants; (Aim 2) Use MHC class II multimer-based methods to sort allergen-specific single cells, and perform targeted RNA-Seq to investigate their molecular signatures and clonal ancestry at single-cell resolution; and (Aim 3) Quantify epigenetic changes (i.e., methylation of CpG islands) in key genes (i.e., FOXP3, IL4, IFNg, IL10) to assess possible links between the methylation and the desensitization and sustained unresponsiveness resulting from OIT. The results from this study of T cell phenotype, function and epigenetics will enable us: to identify which of these immune features will be most useful as signatures of multi-OIT-induced desensitization and sustained unresponsiveness; to identify patterns of changes in T cells that are associated with these distinct clinical outcomes of multi-OIT; and to determine how these patterns are modified by adding treatment with omalizumab to the multi-OIT protocol.