Cellular stratification of atopic inflammatory circuits

天然免疫细胞在食物过敏中起重要作用，其中抗原呈递细胞（APC）引发初始T细胞应答，而肥大细胞（或嗜碱性粒细胞）是过敏反应中的主要效应细胞。在第一个资助期（FP），我们开发了嗜碱性粒细胞激活试验（BAT），用于研究参与者的常规检测。我们确定了CDSENS的强大诊断能力，即引起50%嗜碱性粒细胞应答激活的抗原浓度，以从BAT测定中预测食物过敏。CDSENS与口服食物激发阈值剂量密切相关，表明脱敏期间反应阈值的评估是相关的。与我们的BAT，我们还评估了浆细胞和经典的树突状细胞（pDC和cDC），这表现出耐受性和过敏individuals.To评估的磷酸化模式，激活和抑制标记物的诱导嗜碱性粒细胞激活之间的显着差异磷酸化S6，我们利用质谱细胞术。 我们观察到耐受性和过敏性供体之间CD300a、CD33和CD32b的诱导显著不同，表明这些作为食物过敏的新型生物标志物的候选者。最后，我们评估了过敏原刺激后三天APC的激活，从而确定过敏供体中几个APC亚群的特应性极化特征，特别是关于可能在脱敏中起作用的调节受体（CD103，PDL 1，CTLA 4）的表达变化。我们将在第二次FP的扩展研究中继续这些现已确立的试验，以完成不断增长的数据体。此外，我们想确定这些特征是否存在于其他2型疾病中。将质谱流式细胞术BAT试验开发为常规流式细胞术试验。此外，我们将建立在我们的见解APC极化食物过敏原，并将评估是否不同的介质，miRNA或短链脂肪酸修改APC表型在过敏原刺激（与B5和C2合作），以及如何这些不同的APC子集可以在功能上影响T细胞启动。在该测定系统中，我们将使用称为PADRE的泛HLA DR肽，其允许广泛激活初始以及记忆CD4+ T细胞。总之，我们的数据将阐明先天免疫细胞在过敏诱导、维持和耐受中的作用。

Innate immune cells play an important role in food allergy with antigen-presenting cells (APC) priming the initial T cell response, while mast cells (or basophils) being major effector cells in allergic reactions. In the 1st Funding Period (FP), we developed a Basophil Activation Test (BAT) for routine testing of the study participants. We determined a strong diagnostic power of the CDSENS, the antigen concentration evoking activation of 50% basophil response, to predict food allergy from the BAT assay. CDSENS correlated strongly with the oral food challenge threshold dose, indicating that the assessment of the reaction threshold during desensitization is relevant. With our BAT, we also assess phosphorylation of S6 in plasmacytoid and classical dendritic cells (pDC and cDC), which displayed significant differences between tolerant and allergic individuals.To assess the induction of phosphorylation patterns, activation and inhibition markers during basophil activation, we utilized mass cytometry. We observed a significant different induction of CD300a, CD33 and CD32b between tolerant and allergic donors, suggesting these as candidates as novel biomarkers in food allergy. Finally, we assessed the activation of APC three days following allergen stimulation, thereby identifying atopic polarization profiles of several APC subsets in allergic donors, especially regarding the expression changes of regulatory receptors (CD103, PDL1, CTLA4) that may play a role in desensitization. We will continue these now well-established assays in the extension studies in the 2nd FP to complete the growing data body. Furthermore, we want to determine whether these signatures are present in other type 2 disorders. The mass cytometric BAT assay will be developed to a conventional flow cytometry assay. In addition, we will build upon our insights into APC polarization by food allergens and will assess whether different mediators, miRNAs or short chain fatty acids modify APC phenotypes during allergen stimulation (in collaboration with B5 and C2), and how these different APC subsets can functionally affect T cell priming. In this assay system, we will make use of a Pan-HLA-DR-peptide called PADRE, that allows for broad activation of naive as well as memory CD4+ T cells. Altogether, our data will clarify the role of innate immune cells in allergy induction, maintenance and tolerization.