Department of Dermatology, University Medical Center of the Johannes Gutenberg-Universität, Mainz, Germany.
J Allergy Clin Immunol. 2013 May;131(5):1384-92.e6. doi: 10.1016/j.jaci.2012.10.037. Epub 2012 Dec 11.
IgE- and T-cell cross-reactivity contribute to the birch pollen-food syndrome.
We performed a comprehensive analysis of T-cell cross-reactivity in primary cell cultures, facilitating the identification of allergen-specific T-cell subpopulations from individual patients.
Patients with birch pollen allergy and associated food allergy to hazelnuts, carrots, or both were analyzed for IgE cross-reactivity, T-cell responses, and T-cell cross-reactivity to recombinant Bet v 1.0101 (Bet v 1; birch), Cor a 1.0401 (Cor a 1; hazelnut), and Dau c 1.0104 (Dau c 1; carrot). A novel flow cytometry-based method using a 2-step staining process with fluorescent dyes was established to identify subpopulations of cross-reactive T cells.
IgE-binding inhibition tests of individual sera revealed that the vast majority of Cor a 1-reactive IgE was cross-reactive to Bet v 1, whereas Bet v 1-reactive IgE was only partially inhibited by preincubation with Cor a 1. Primary stimulation of T cells with Bet v 1 or Cor a 1 resulted in a significant increase in specific responses to Cor a 1 or Bet v 1 after secondary stimulation, respectively, indicating T-cell cross-reactivity between birch and hazelnut allergens in all patients of the study cohort. Preactivation with Dau c 1 induced less pronounced effects. A novel flow cytometry-based proliferation assay identified a predominant Cor a 1/Bet v 1-cross-reactive T-cell subpopulation within highly Bet v 1/Cor a 1-responsive T cells.
Analysis of primary allergen-specific T cells combined with flow cytometry-based proliferation assays facilitates investigation of allergen-specific T-cell subpopulations in subjects and might be helpful to evaluate the effect of birch-specific immunotherapy on pollen-associated food allergies.
IgE 和 T 细胞交叉反应导致桦树花粉-食物综合征。
我们对原代细胞培养中的 T 细胞交叉反应进行了全面分析，从而能够从个体患者中鉴定过敏原特异性 T 细胞亚群。
对桦树花粉过敏并伴有榛子、胡萝卜或两者过敏的患者进行 IgE 交叉反应、T 细胞反应以及重组 Bet v 1.0101（Bet v 1；桦树）、Cor a 1.0401（Cor a 1；榛子）和 Dau c 1.0104（Dau c 1；胡萝卜）的 T 细胞交叉反应分析。建立了一种基于新型流式细胞术的两步染色荧光染料法，用于鉴定交叉反应性 T 细胞亚群。
对个体血清的 IgE 结合抑制试验表明，绝大多数 Cor a 1 反应性 IgE 与 Bet v 1 交叉反应，而 Bet v 1 反应性 IgE 仅部分被 Cor a 1 预孵育抑制。用 Bet v 1 或 Cor a 1 对 T 细胞进行初次刺激后，分别用 Cor a 1 或 Bet v 1 进行二次刺激，导致特异性反应显著增加，表明研究队列中的所有患者桦树和榛子过敏原之间存在 T 细胞交叉反应。用 Dau c 1 预激活诱导的作用不那么明显。基于新型流式细胞术的增殖测定法在高度 Bet v 1/Cor a 1 反应性 T 细胞内鉴定出主要的 Cor a 1/Bet v 1 交叉反应性 T 细胞亚群。
分析原代过敏原特异性 T 细胞结合基于流式细胞术的增殖测定法有助于研究受试者中过敏原特异性 T 细胞亚群，并且可能有助于评估桦树特异性免疫疗法对花粉相关食物过敏的影响。
