Kobayashi Yukihiro, Kakemoto Seiko, Shimakura Kuniyoshi, Shiomi Kazuo
Department of Marine Biosciences, Tokyo University of Marine Science and Technology.
Shokuhin Eiseigaku Zasshi. 2015;56(5):194-9. doi: 10.3358/shokueishi.56.194.
The nematode Anisakis simplex is a representative parasite infecting marine animals. When third stage larvae of A. simplex infecting fish and squids are ingested by humans, individuals previously sensitized by this parasite may experience IgE-mediated allergic reactions. So far, as many as 13 kinds of proteins (Ani s 1-13) have been identified as A. simplex allergens but several more unknown allergens are suggested to exist. In this study, therefore, chemiluminescent immunoscreening of an expression cDNA library constructed from the third stage larvae was conducted to identify a new allergen. As a result, an IgE-positive clone coding for a 23.5 kDa protein (named Ani s 14) composed of 217 amino acid residues was isolated. The regions 4-147 and 34-123 of Ani s 14 share 31% identity with the region 796-940 of Ani s 7 and 32% identity with the region 2-91 of Ani s 12, respectively. Recombinant Ani s 14 was successfully expressed in Escherichia coli as a His-tagged protein and shown to be IgE reactive to 14 (54%) of 26 sera from Anisakis-allergic patients. In conclusion, Ani s 14 is a new major allergen of A. simplex that is specific to Anisakis-allergic patients.
线虫简单异尖线虫是一种感染海洋动物的代表性寄生虫。当人类摄入感染鱼类和鱿鱼的简单异尖线虫第三期幼虫时，先前被这种寄生虫致敏的个体可能会发生IgE介导的过敏反应。到目前为止，已鉴定出多达13种蛋白质（Ani s 1-13）为简单异尖线虫过敏原，但据推测还存在几种未知的过敏原。因此，在本研究中，对由第三期幼虫构建的表达cDNA文库进行了化学发光免疫筛选，以鉴定一种新的过敏原。结果，分离出一个编码由217个氨基酸残基组成的23.5 kDa蛋白质（命名为Ani s 14）的IgE阳性克隆。Ani s 14的4-147和34-123区域分别与Ani s 7的796-940区域有31%的同一性，与Ani s 12的2-91区域有32%的同一性。重组Ani s 14在大肠杆菌中成功表达为His标签蛋白，并显示对来自异尖线虫过敏患者的26份血清中的14份（54%）具有IgE反应性。总之，Ani s 14是简单异尖线虫的一种新的主要过敏原，对异尖线虫过敏患者具有特异性。
