T Cell Pathogenesis of Food Allergy

食物过敏的 T 细胞发病机制

• 批准号: 7964587
• 负责人: Calman Prussin
• 金额: $ 111.71万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7964587
• 关键词: Accounting; Allergens; Allergic; Anaphylaxis; Antigens; Biological Assay; Biopsy; CD4 Positive T Lymphocytes; CD8B1 gene; Cells; Characteristics; Chronic; Clinical Research; Data; Development; Disease; Exposure to; Flow Cytometry; Food; Food Hypersensitivity; Frequencies; Future; Gastrointestinal Diseases; Gastrointestinal tract structure; Goals; IgE; Immediate hypersensitivity; Immune response; Incidence; Inflammation; Inflammatory; Interferon Type II; Interleukin-4; Interleukin-5; Link; Measures; Pathogenesis; Patients; Peanuts - dietary; Prevalence; Production; Recruitment Activity; Relative (related person); Research Design; Shrimp; Staining method; Stains; Staphylococcal Enterotoxin B; T memory cell; T-Lymphocyte; T-Lymphocyte Subsets; TNF gene; Th2 Cells; Work; cohort; cytokine; eosinophil; eosinophilic gastroenteritis; food allergen; immunoregulation; research study; response; soy

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. Antigen specific CD4 T cell responses were detectable at 10 cells per 10e6. Boolean analysis of the polychromatic data was performed, to yield 5 distinct subpopulations of food allergen specific CD4 T cells: IL-5+ Th2 (IL-4+, IL-5+) and IL-5- Th2 (IL-4+, IL-5-) cells, Th0, Th1, and TNF solo producers. Peanut specific IL-5+ Th2 cells were present at a 20-fold greater frequency in AEG vs. PA (81 vs. 4 per 10e6 CD4 cells, p=0.05), whereas there were similar frequencies of IL-5- Th2 cells (67 vs. 41 per 10e6 CD4 cells). For all food responses, IL-5+ Th2 cells accounted for a significantly greater fraction of the antigen specific cells in AEG relative to PA (29% vs. 4%, p<0.0001). In PA, but not AEG, IL-5- Th2 responses to peanut were highly correlated with peanut specific IgE (r= 0.87 vs. 0.55, respectively). All subject groups elicited similar very low magnitude Th1 responses to food Ags. 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 underway to extend these findings to gut resident T cells in patients with eosinophilic GI disease. GI biopsies will be obtained and both flow cytometry and immunohistochemisty will be used to determine if a similar association with IL-5+ Th2 cells exists. Additional experiments will identify if there are other characteristics of food allergen specific Th2 cells in these disease states that may specifically contribute to anaphylactic vs. eosinophilic inflammatory food allergy. 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.

为了检查食物过敏反应和EGID中的食物过敏原特异性T细胞应答，招募患有花生过敏反应（PA）、过敏性嗜酸性粒细胞性胃肠炎（AEG）或健康非特应性对照（NA）的受试者。使用细胞内细胞因子染色和多色流式细胞术测量效应/记忆T细胞的细胞因子应答。在CD 4和CD 8 T细胞亚群中测量IL-4、IL-5、IFN-γ和TNF应答。研究的抗原包括花生、Ara h1、大豆、虾和葡萄球菌肠毒素B（SE B）。 食物过敏原特异性T细胞应答仅在CD 4 T细胞区室中发现，并且在两个食物过敏队列中均明确证实。所有组的组成性细胞因子产生均较低。特别是，AEG受试者没有表现出组成性IL-5表达。在10个细胞/10 e6下可检测到抗原特异性CD 4 T细胞应答。 对多色数据进行布尔分析，以产生食物过敏原特异性CD 4 T细胞的5个不同亚群：IL-5+ Th 2（IL-4+，IL-5+）和IL-5-Th 2（IL-4+，IL-5-）细胞，Th 0，Th 1和TNF单独产生者。花生特异性IL-5+ Th 2细胞在AEG中的频率比PA高20倍（每10 e6 CD 4细胞81对4，p=0.05），而IL-5-Th 2细胞的频率相似（每10 e6 CD 4细胞67对41）。对于所有食物反应，IL-5+ Th 2细胞占AEG中抗原特异性细胞的比例显著高于PA（29%对4%，p<0.0001）。在PA中，而不是AEG中，对花生的IL-5-Th 2应答与花生特异性IgE高度相关（分别为r= 0.87和0.55）。所有受试者组引起了类似的非常低的幅度Th 1反应的食物抗原。 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细胞的存在之间存在显著相关性。鉴于IL-5是一种主要的嗜酸性粒细胞活性细胞因子，这种关联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EGID中发现的嗜酸性粒细胞炎症。 此外，这些发现表明，虽然IL-4和IL-5的表达是相关的，但各自以不同的方式控制，这可能对过敏性疾病的免疫发病机制具有重要影响。 目前的工作正在进行中，以扩大这些发现肠道居民T细胞在嗜酸性胃肠道疾病患者。将获得GI活组织检查，并使用流式细胞术和细胞化学来确定是否存在与IL-5+ Th 2细胞的类似关联。另外的实验将鉴定在这些疾病状态中是否存在食物过敏原特异性Th 2细胞的其他特征，其可能特异性地促成过敏性与嗜酸性粒细胞炎性食物过敏。 目前的工作旨在继续发展高保真多色流式细胞术测定，以过敏原特异性方式同时检查多种Th 2细胞因子（IL-4，-5，-9，-13）。这种技术能力将促进未来的干预性临床研究，旨在研究花生过敏反应和EGIDs中过敏性Th 2反应的免疫调节。