Mechanistic Study of Peanut-specific T cells Pre and Post Oral Immunotherapy

描述（由申请人提供）：花生过敏是一种常见的食物过敏，与致命的过敏反应有关。诊断是复杂的存在致敏受试者（如IgE或皮肤点刺试验测定），可以食用花生没有临床反应。花生过敏的标准治疗是警惕地避免和管理肾上腺素的情况下意外暴露。最近的口服和舌下免疫治疗的临床试验已经证明了疗效，但没有建立体外诊断测定来监测对治疗的反应。虽然过敏是IgE介导的疾病，但越来越多的证据表明过敏原特异性CD 4 + T细胞在疾病发展中起重要作用。显著的技术挑战，包括低频率和多种花生过敏原的存在，限制了花生过敏受试者中花生特异性CD 4 + T细胞的研究。该提案的首要主题是建立花生特异性CD 4 + T细胞的频率、表型和分子特征与过敏状态（即非过敏、致敏但耐受、临床过敏和脱敏或耐受（IT后））之间的机制相关性。将有三个具体目标。目的1将利用四聚体分析和CD 154上调分析来表征不同过敏状态受试者中花生特异性CD 4 + T细胞。我们的主要目标是确定一个T细胞频率阈值，可以识别受试者与真正的花生过敏。其他目标包括研究T细胞对单个花生过敏原的反应，基于疾病状态和HLA类型与T细胞对特定花生过敏原的反应性的关联。目的2利用RNA-seq和Fluidigm基因芯片技术研究花生特异性CD 4 + T细胞在过敏和非过敏受试者中的转录特征。我们的主要目标将是定义一个独特的转录签名， 与过敏性表型有关。对一些在Th 2细胞中发现的新基因的功能也将进行研究。目标3将把在前几个目标中获得的成果和工具应用于 开发一种常规诊断方法来衡量免疫疗法的疗效。我们将通过表征ITN口服花生免疫疗法试验中受试者的T细胞来检验花生反应性T细胞的频率、表型和分子特征与免疫疗法治疗功效相关的假设。

DESCRIPTION (provided by applicant): Peanut allergy is a common food allergy that is associated with fatal anaphylactic reactions. Diagnosis is complicated by the presence of sensitized subjects (as assayed by IgE or skin prick test) that can consume peanut with no clinical reaction. Standard treatment for peanut allergy is vigilant avoidance and administration of epinephrine in case of accidental exposure. Recent clinical trials of oral and sublingual immunotherapy have demonstrated efficacy, but there is no established in vitro diagnostic assay to monitor response to therapy. While allergy is an IgE mediated disease, accumulating evidence suggests that allergen specific CD4+ T cells play a significant role in disease development. Significant technical challenges, including low frequencies and the presence of multiple peanut allergens, have limited the study of peanut specific CD4+ T cells in subjects with peanut allergy. The overarching theme of this proposal is establishing a mechanistic correlation between the frequency, phenotype, and molecular signature of peanut specific CD4+ T cells and allergic status, i.e. non-allergic, sensitized but tolerant, clinically allergic, and de-sensitzed or tolerized (following IT). There will be three specific aims. Aim 1 will utilize tetramer assays and CD154 up-regulation assays to characterize peanut specific CD4+ T cells in subjects with different allergic status. Our key objective is to define a T cell frequency threshold that can identify subjects with true peanut allergy. Other objectives include studying T cell responses toward individual peanut allergens based on disease status and association of HLA type with T cell reactivity towards specific peanut allergens. Aim 2 will utilize RNA-seq and Fluidigm microarrays to study the transcriptional signature of peanut specific CD4+ T cells in allergic and non-allergic subjects. Our main objective will be to define a unique transcriptional signature that is associated with allergic phenotypes. The function of some of the novel gene identified in Th2 cells will also be studied. Aim 3 will apply the results and tools obtained in the previous aims to develop a routine diagnostic to measure the efficacy of immunotherapy. We will test the hypothesis that the frequency, phenotype and molecular signature of peanut reactive T cells correlate with the efficacy of immunotherapy treatment by characterizing T cells from subjects in an ITN oral peanut immunotherapy trial.