Memory T Cell Responses to Food Allergy

为了检测食物过敏反应和EGID的食物过敏原特异性T细胞反应，研究对象包括花生过敏(PA)、过敏性嗜酸性胃肠炎(AEG)和健康非特应性对照(NA)受试者。用细胞内细胞因子染色和多色流式细胞术检测效应/记忆T细胞细胞因子反应。检测CD4和CD8T细胞亚群中IL-4、IL-5、干扰素-γ和肿瘤坏死因子的反应。被研究的抗原包括花生、Ara H1、大豆、虾和葡萄球菌肠毒素B(SEB)。 食物过敏原特异性T细胞反应仅在CD4T细胞室内被发现，并且在两个食物过敏队列中都明显可见。所有组的组成性细胞因子的产生都很低。特别是，AEG受试者没有表现出结构性的IL-5表达。花生特异性IL-4+T细胞在PA组和AEG组中的频率相似，但在NA组中不同。与IL-4相比，AEG组食物过敏原特异性IL-5+T细胞的频率明显高于PA组和NA组。此外，与PA或NA受试组相比，AEG受试者对非花生食物过敏原表现出更强的IL-4和IL-5反应。与上述情况相反，3名非过敏性EG受试者没有食物过敏原特异性Th2反应。与抗原特异性数据一致，CD4T细胞对SEB的反应表明，与其他受试者组相比，AEG与IL-5+细胞的频率显著增加有关。 这些发现表明，AEG疾病状态与多种食物过敏原中表达IL-5的食物过敏原特异性T细胞的存在显著相关。鉴于IL-5是一种主要的嗜酸性粒细胞活性细胞因子，这种联系可能具有免疫病理学意义，并表明产生IL-5的食物过敏原特异性T细胞驱动在EGID中发现的嗜酸性炎症。此外，这些发现表明，尽管IL-4和IL-5的表达是关联的，但各自以不同的方式受到控制，这可能对变态反应性疾病的免疫发病机制产生重要影响。 目前的工作旨在继续发展高保真多色流式细胞术，以过敏原特异性的方式同时检测多种Th2细胞因子(IL-4、-5、-9、-13)。这一技术能力将促进未来的干预性临床研究，旨在检查花生过敏反应和EGID中过敏Th2反应的免疫调节。

To examine food allergen specific T cell responses in food anaphylaxis and EGIDs, cohorts with peanut anaphylaxis (PA), allergic eosinophilic gastroenteritis (AEG), or healthy non-atopic control (NA) subjects were recruited. Effector/memory T cell cytokine responses were measured using intracellular cytokine staining and polychromatic flow cytometry. IL-4, IL-5, IFN-gamma and TNF responses were measured in both the CD4 and CD8 T cell subsets. Antigens that were studied included peanut, Ara h1, soy, shrimp, and staphylococcal enterotoxin B (SEB). Food allergen specific T cell responses were found exclusively within the CD4 T cell compartment and were clearly demonstrable in both food allergic cohorts. Constitutive cytokine production was low for all groups. In particular, AEG subjects did not demonstrate constitutive IL-5 expression. Similar frequencies of peanut specific IL-4+ T cells were found in both the PA and AEG subject groups, but not in the NA group. In contrast to IL-4, the frequency of food allergen specific IL-5+ T cells was significantly higher in the AEG group relative to both the PA and NA subjects. Furthermore, AEG subjects demonstrated greater IL-4 and IL-5 responses to non-peanut food allergens than either the PA or NA subject groups. In contrast to the above, a group of 3 subjects with non-allergic EG did not have food allergen specific Th2 responses. In agreement with the antigen specific data, CD4 T cell responses to SEB demonstrated that AEG was associated with a significantly greater frequency of IL-5+ cells relative to the other subject groups. These findings demonstrate a significant correlation between AEG disease status and the presence of IL-5 expressing food allergen specific T cells across multiple food allergens. Given that IL-5 is a major eosinophil active cytokine, it is likely that this association is of immunopathological significance and suggests that IL-5 producing food allergen specific T cells drive the eosinophilic inflammation found in EGIDs. Additionally, these findings suggest that although the expression of IL-4 and IL-5 are linked, each is controlled in a different manner, which may have important consequences for the immunopathogenesis of allergic diseases. Current work is aimed at continued development of high fidelity polychromatic flow cytometry assays to simultaneously examine multiple Th2 cytokines (IL-4, -5, -9, -13) in an allergen specific manner. This technical capacity will facilitate future interventional clinical studies designed to examine immunomodulation of allergic Th2 responses in peanut anaphylaxis and EGIDs.