Christian Doppler Laboratory for Allergy Diagnosis and Therapy, University of Salzburg, Salzburg, Austria.
PLoS One. 2011;6(8):e24150. doi: 10.1371/journal.pone.0024150. Epub 2011 Aug 29.
Celery (Apium graveolens) represents a relevant allergen source that can elicit severe reactions in the adult population. To investigate the sensitization prevalence and cross-reactivity of Api g 2 from celery stalks in a Mediterranean population and in a mouse model.
786 non-randomized subjects from Italy were screened for IgE reactivity to rApi g 2, rArt v 3 (mugwort pollen LTP) and nPru p 3 (peach LTP) using an allergen microarray. Clinical data of 32 selected patients with reactivity to LTP under investigation were evaluated. Specific IgE titers and cross-inhibitions were performed in ELISA and allergen microarray. Balb/c mice were immunized with purified LTPs; IgG titers were determined in ELISA and mediator release was examined using RBL-2H3 cells. Simulated endolysosomal digestion was performed using microsomes obtained from human DCs.
IgE testing showed a sensitization prevalence of 25.6% to Api g 2, 18.6% to Art v 3, and 28.6% to Pru p 3 and frequent co-sensitization and correlating IgE-reactivity was observed. 10/32 patients suffering from LTP-related allergy reported symptoms upon consumption of celery stalks which mainly presented as OAS. Considerable IgE cross-reactivity was observed between Api g 2, Art v 3, and Pru p 3 with varying inhibition degrees of individual patients' sera. Simulating LTP mono-sensitization in a mouse model showed development of more congruent antibody specificities between Api g 2 and Art v 3. Notably, biologically relevant murine IgE cross-reactivity was restricted to the latter and diverse from Pru p 3 epitopes. Endolysosomal processing of LTP showed generation of similar clusters, which presumably represent T-cell peptides.
Api g 2 represents a relevant celery stalk allergen in the LTP-sensitized population. The molecule displays common B cell epitopes and endolysosomal peptides that encompass T cell epitopes with pollen and plant-food derived LTP.
芹菜（Apium graveolens）是一种重要的过敏原来源，可在成年人群中引发严重反应。本研究旨在调查地中海人群和小鼠模型中芹菜茎秆Api g 2 的致敏流行率和交叉反应性。
使用过敏原微阵列对来自意大利的 786 名非随机受试者进行 rApi g 2、rArt v 3（艾蒿花粉 LTP）和 nPru p 3（桃 LTP）的 IgE 反应性筛查。评估了 32 名经调查显示对 LTP 有反应的患者的临床数据。在 ELISA 和过敏原微阵列中进行了特异性 IgE 滴度和交叉抑制试验。用纯化的 LTP 免疫 Balb/c 小鼠；用 ELISA 测定 IgG 滴度，并使用 RBL-2H3 细胞检测介质释放。用人 DCs 获得的微粒体进行模拟内溶酶体消化。
IgE 检测显示，对 Api g 2 的致敏流行率为 25.6%，对 Art v 3 的致敏流行率为 18.6%，对 Pru p 3 的致敏流行率为 28.6%，且经常发生共致敏，并观察到相关的 IgE 反应性。10/32 名患有 LTP 相关过敏的患者在食用芹菜茎后出现症状，主要表现为 OAS。在 Api g 2、Art v 3 和 Pru p 3 之间观察到相当大的 IgE 交叉反应性，个体患者血清的抑制程度不同。在小鼠模型中模拟 LTP 单致敏显示，Api g 2 和 Art v 3 之间发展出更一致的抗体特异性。值得注意的是，生物相关的鼠类 IgE 交叉反应性仅限于后者，与 Pru p 3 表位不同。LTP 的内溶酶体处理显示生成了相似的簇，推测这些簇代表 T 细胞肽。
Api g 2 是 LTP 致敏人群中一种重要的芹菜茎过敏原。该分子具有共同的 B 细胞表位和内溶酶体肽，包含花粉和植物源性 LTP 的 T 细胞表位。
