Global Research, ALK, Hørsholm, Denmark.
Louis Pasteur University Hospital, Košice, Slovak Republic.
Allergy. 2020 Jan;75(1):137-147. doi: 10.1111/all.13992. Epub 2019 Aug 21.
Ragweed frequently causes seasonal allergies in North America and Europe. In the United States, several related ragweed species with diverse geographical distribution cause allergic symptoms. Cross-reactivity towards related ragweed species of IgE and treatment-induced IgG has been demonstrated previously. However, less is known about the underlying T-cell cross-reactivity.
The allergen content of ragweed extracts was determined by mass spectrometry and related to T-cell epitopes of Amb a allergens (group 1, 3, 4, 5, 8 and 11) in 20 American ragweed allergic patients determined by FluoroSpot and proliferation assays. T-cell responses to 50 frequently recognized Amb a-derived T-cell epitopes and homologous peptides from western ragweed (Amb p), giant ragweed (Amb t) and mugwort (Art v) were investigated in an additional 11 American and 14 Slovakian ragweed allergic donors.
Ragweed extracts contained all known allergens and isoallergens thereof. Donor T-cell responses were diverse and directed against all Amb a 1 isoallergens and to most minor allergens investigated. Similar response patterns were seen in American and Slovakia donors. Several epitopes were cross-reactive between isoallergens and ragweed species, some even including mugwort. T-cell cross-reactivity generally correlated with allergen sequence homology.
T-cell epitopes of multiple allergens/isoallergens are involved in the diverse T-cell responses in ragweed allergic individuals. T-cell lines were highly cross-reactive to epitopes of related ragweed species without any apparent geographical response bias. These data support that different ragweed species can be considered an allergen homology group with Amb a as the representative species regarding diagnosis as well as allergy immunotherapy.
豚草常引起北美和欧洲的季节性过敏。在美国，几种具有不同地理分布的相关豚草物种会引起过敏症状。先前已经证明了对相关豚草物种的 IgE 和治疗诱导的 IgG 的交叉反应。然而，对潜在的 T 细胞交叉反应知之甚少。
通过质谱法确定豚草提取物中的过敏原含量，并与通过 FluoroSpot 和增殖测定确定的 20 名美国豚草过敏患者的 Amb a 过敏原（第 1、3、4、5、8 和 11 组）的 T 细胞表位相关联。在另外的 11 名美国和 14 名斯洛伐克豚草过敏供体中，研究了对 50 个经常识别的 Amb a 衍生 T 细胞表位和来自西方豚草（Amb p）、巨型豚草（Amb t）和艾蒿（Art v）的同源肽的 T 细胞反应。
豚草提取物包含所有已知的过敏原及其同工过敏原。供体 T 细胞反应多种多样，针对所有 Amb a 1 同工过敏原和大多数研究的次要过敏原。在美国和斯洛伐克供体中观察到相似的反应模式。一些表位在同工过敏原和豚草物种之间具有交叉反应性，有些甚至包括艾蒿。T 细胞交叉反应性通常与过敏原序列同源性相关。
多种过敏原/同工过敏原的 T 细胞表位参与了豚草过敏个体的多样化 T 细胞反应。T 细胞系对相关豚草物种的表位具有高度交叉反应性，没有明显的地理反应偏向。这些数据支持不同的豚草物种可以被认为是一个过敏原同源群，以 Amb a 作为代表性物种，无论是在诊断还是过敏免疫治疗方面。
