Midoro-Horiuti Terumi, Schein Catherine H, Mathura Venkatarajan, Braun Werner, Czerwinski Edmund W, Togawa Akihisa, Kondo Yasuto, Oka Tetsuo, Watanabe Masanao, Goldblum Randall M
Department of Pediatrics, Child Health Research Center, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0366, USA.
Mol Immunol. 2006 Feb;43(6):509-18. doi: 10.1016/j.molimm.2005.05.006. Epub 2005 Jun 21.
The group 1 allergens are a major cause of cedar pollen hypersensitivity in several geographic areas. Allergens from several taxa have been shown to cross-react. The goal of these studies was to compare the structural features of the shared and unique epitopes of the group 1 allergen from mountain cedar (Jun a 1) and Japanese cedar (Cry j 1). An array of overlapping peptides from the sequence of Jun a 1 and a panel of monoclonal anti-Cry j 1 antibodies were used to identify the IgE epitopes recognized by cedar-sensitive patients from Texas and Japan. IgE from Japanese patients reacted with peptides representing one of the two linear epitopes within the highly conserved beta-helical core structure and both epitopes within less ordered loops and turns near the N- and C-termini of Jun a 1. A three-dimensional (3D) model of the Cry j 1, based on the crystal structure of Jun a 1, indicated a similar surface exposure for the four described epitopes of Jun a 1 and the homologous regions of Cry j 1. The monoclonal antibodies identified another shared epitope, which is most likely conformational and a unique Cry j 1 epitope that may be the previously recognized glycopeptide IgE epitope. Defining the structural basis for shared and unique epitopes will help to identify critical features of IgE epitopes that can be used to develop mimotopes or identify allergen homologues for vaccine development.
第1组变应原是几个地理区域中雪松花粉过敏的主要原因。已证明来自几个分类群的变应原会发生交叉反应。这些研究的目的是比较山地雪松（Jun a 1）和日本雪松（Cry j 1）第1组变应原共有和独特表位的结构特征。使用一系列来自Jun a 1序列的重叠肽和一组抗Cry j 1单克隆抗体，来鉴定来自德克萨斯州和日本的雪松敏感患者所识别的IgE表位。日本患者的IgE与代表高度保守的β-螺旋核心结构内两个线性表位之一的肽发生反应，以及与Jun a 1 N端和C端附近较无序的环和转角内的两个表位发生反应。基于Jun a 1晶体结构的Cry j 1三维（3D）模型表明，Jun a 1的四个所述表位和Cry j 1的同源区域具有相似的表面暴露。单克隆抗体鉴定出另一个共有表位，它很可能是构象性的，还有一个独特的Cry j 1表位，可能是先前识别的糖肽IgE表位。确定共有和独特表位的结构基础将有助于识别IgE表位的关键特征，这些特征可用于开发模拟表位或鉴定用于疫苗开发的变应原同源物。
