Isoforms of the major peanut allergen ara h 2: IgE binding in children with peanut allergy
Isoforms of the major peanut allergen ara h 2: IgE binding in children with peanut allergy
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DOI：
10.1159/000080652
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发表时间：
2004-01-01
影响因子：
2.8
通讯作者：
Thomas, WR
中科院分区：
文献类型：
--
作者：
Hales, BJ;Bosco, A;Thomas, WR
背景：主要的花生过敏原 Ara h 2 由两种亚型组成，即 Ara h 2.0101 和 Ara h 2.0201。最近鉴定的 Ara h 2.0201 同种型含有额外的 12 个氨基酸，其中包括报道的免疫显性表位 DPYSPS 的额外副本。本研究旨在评估两种 Ara h 2 亚型的 IgE 结合。方法：对 10 个 Ara h 2 克隆进行测序，以评估 Ara h 2 同工型的相对频率，并鉴定 Ara h 2 序列是否存在进一步变异。使用IgE DELFIA TM 测定法测量了70名花生过敏儿童与Ara h 2.0101和Ara h 2.0201的IgE结合，以定量特异性IgE结合。使用竞争测定来测量Ara h 2.0201是否含有除Ara h 2.0101中发现的IgE表位之外的IgE表位。结果：6/10 个克隆发现了原始 Ara h 2.0101 序列，2/10 个克隆发现了 Ara h 2.0201。 Ara h 2.0201 具有预期的 12 个氨基酸插入以及位置 40 (40G) 和 142 (142E) 处的取代。两种新亚型被鉴定为位置142的不同多态性。一种Ara h 2.01克隆(Ara h 2.0102)包含142E，一种Ara h 2.02克隆(Ara h 2.0202)包含142D。在这 10 个序列中，均未发现其他研究人员之前在第 77 位（77Q 或 77R）发现的多态性。尽管个别患者与 Ara h 2.0201 结合的 IgE 水平经常高于与 Ara h 2.0101 的结合 (p
Background: The major peanut allergen Ara h 2 consists of two isoforms, namely Ara h 2.0101 and Ara h 2.0201. The recently identified Ara h 2.0201 isoform contains an extra 12 amino acids including an extra copy of the reported immunodominant epitope DPYSPS. This study aimed to evaluate the IgE binding of the two Ara h 2 isoforms. Methods: Ten clones of Ara h 2 were sequenced to assess the relative frequency of the Ara h 2 isoforms and to identify whether there was further variation in the Ara h 2 sequence. IgE binding to Ara h 2.0101 and Ara h 2.0201 was measured for 70 peanut-allergic children using an IgE DELFIA(TM) assay to quantitate specific IgE binding. A competition assay was used to measure whether Ara h 2.0201 contained IgE epitopes other than those found for Ara h 2.0101. Results: The original Ara h 2.0101 sequence was found for 6/10 clones and Ara h 2.0201 was found for 2/10 clones. Ara h 2.0201 had the expected insertion of 12 amino acids as well as substitutions at positions 40 (40G) and 142 (142E). Two new isoforms were identified as different polymorphisms of position 142. One Ara h 2.01 clone (Ara h 2.0102) contained 142E and one Ara h 2.02 clone (Ara h 2.0202) contained 142D. A polymorphism that was previously identified by other investigators at position 77 (77Q or 77R) was not found for any of the 10 sequences. Although the level of IgE binding to Ara h 2.0201 of individual patients was frequently higher than the binding to Ara h 2.0101 (p