由特异性IgE(sIgE)介导的食物过敏对社会具有显著的社会经济影响。评估来自不同过敏原来源的过敏原之间的IgE交叉反应性可以更好地管理这些对食品蛋白质的潜在威胁生命的不良反应并提高食品安全。一种新颖的香蕉水果过敏原,S-腺苷-L-同型半胱氨酸水解酶(SAHH),最近已经鉴定并且其重组同源物在大肠杆菌中异源过量产生。在这项研究中,我们在NCBI(国家生物技术信息中心)搜索黑麦草中的SAHH同源物,乳胶,还有猕猴桃,所有这些通常都与花粉-乳胶-水果综合征有关。此外,Western免疫印迹分析用于鉴定乳胶过敏患者血清中与香蕉SAHH的交叉反应性IgE。猕猴桃过敏,和黑麦草过敏.ClustalOmega分析表明,黑麦草中香蕉SAHH同源物之间的氨基酸序列同一性超过92%,乳胶,还有猕猴桃.除了五个B细胞表位,计算机模拟分析预测了香蕉SAHH中的11个T细胞表位,十七个猕猴桃SAHH,12在黑麦草SAHH,和八个乳胶SAHH,与7等位基因HLA参考集(HLA-DRB1*03:01,HLA-DRB1*07:01,HLA-DRB1*15:01,HLA-DRB3*01:01,HLA-DRB3*02:02,HLA-DRB4*01:01,HLA-DRB5*01:01)相关。4个T细胞表位在香蕉和猕猴桃SAHH中是相同的(位置328,278,142,341),以及香蕉和黑麦草SAHH(位置278、142、96和341)。所有四个SAHH共有两个T细胞表位(位置278和341)。与所分析蛋白质之间的高氨基酸序列同一性和B细胞表位同源性一致,在三名乳胶过敏患者中的三名中检测到与香蕉SAHH的交叉反应性IgE,六个黑麦草过敏患者中有五个,和三个猕猴桃过敏患者中的两个。虽然香蕉SAHH只在一小群过敏个体中进行了研究,它是一种新型的交叉反应性食物过敏原,在检测花粉-乳胶-水果综合征时应予以考虑.
Food allergies mediated by specific IgE (sIgE) have a significant socioeconomic impact on society. Evaluating the IgE cross-reactivity between allergens from different allergen sources can enable the better management of these potentially life-threatening adverse reactions to food proteins and enhance food safety. A novel banana fruit allergen, S-adenosyl-L-homocysteine hydrolase (SAHH), has been recently identified and its recombinant homolog was heterologously overproduced in E. coli. In this study, we performed a search in the NCBI (National Center for Biotechnology Information) for SAHH homologs in ryegrass,
latex, and kiwifruit, all of which are commonly associated with pollen-
latex-fruit syndrome. In addition, Western immunoblot analysis was utilized to identify the cross-reactive IgE to banana SAHH in the sera of patients with a
latex allergy, kiwifruit allergy, and ryegrass allergy. ClustalOmega analysis showed more than 92% amino acid sequence identity among the banana SAHH homologs in ryegrass,
latex, and kiwifruit. In addition to five B-cell epitopes, in silico analysis predicted eleven T-cell epitopes in banana SAHH, seventeen in kiwifruit SAHH, twelve in ryegrass SAHH, and eight in
latex SAHH, which were related to the seven-allele HLA reference set (HLA-DRB1*03:01, HLA-DRB1*07:01, HLA-DRB1*15:01, HLA-DRB3*01:01, HLA-DRB3*02:02, HLA-DRB4*01:01, HLA-DRB5*01:01). Four T-cell epitopes were identical in banana and kiwifruit SAHH (positions 328, 278, 142, 341), as well as banana and ryegrass SAHH (positions 278, 142, 96, and 341). All four SAHHs shared two T-cell epitopes (positions 278 and 341). In line with the high amino acid sequence identity and B-cell epitope homology among the analyzed proteins, the cross-reactive IgE to banana SAHH was detected in three of three latex-allergic patients, five of six ryegrass-allergic patients, and two of three kiwifruit-allergic patients. Although banana SAHH has only been studied in a small group of allergic individuals, it is a novel cross-reactive food allergen that should be considered when testing for pollen-latex-fruit syndrome.