Tordesillas Leticia, Cuesta-Herranz Javier, Gonzalez-Muñoz Miguel, Pacios Luis F, Compés Esther, Garcia-Carrasco Belen, Sanchez-Monge Rosa, Salcedo Gabriel, Diaz-Perales Araceli
Unidad de Bioquimica, Departamento de Biotecnologia, E.T.S. Ingenieros Agronomos, UPM, Madrid, Spain.
Mol Immunol. 2009 Feb;46(4):722-8. doi: 10.1016/j.molimm.2008.10.018. Epub 2008 Dec 2.
Lipid transfer proteins (LTPs), particularly peach Pru p 3, are the most relevant plant food allergens in the South of Europe, and, therefore, their allergic properties have been extensively studied. However, neither T-cell epitopes nor their effect on the patients' T-cell response has been investigated in any member of the LTP panallergen family. The objective of the present study was to map the major T-cell epitopes of Pru p 3, as well as to evaluate their induced T-cell response in peach-allergic versus control subjects. Thus, peripheral blood mononuclear cells (PBMCs) from 18 peach-allergic patients and Pru p 3-specific T-cell lines (TCLs) from 9 of them were cultured with Pru p 3 and with a panel of 17 derived peptides (10-mer overlapping in 5 amino acids representing the full sequence of Pru p 3). Proliferation in 5-day assays was carried out via tritiated-thymidine incorporation, while IL4 and IFNgamma production was assessed via sandwich enzyme-linked immunosorbent tests (ELISA) of TCL culture supernatants. The results were compared to those obtained from 10 non-peach allergic control volunteers. Two consecutive peptides showed the highest activation capacity. About 74% of PBMCs and TCLs recognized them, forming a single T-epitope: Pru p 3(65-80). Additionally, other specific T-cell epitopes were observed. Pru p 3(25-35) was detected by more than 60% of TCLs from peach-allergic patients, and Pru p 3(45-55) only activated PBMCs from control subjects. Interestingly, TCLs from patients were associated with a Th2-type, whereas control TCLs presented a Th1-type cytokine response. The major immunogenic T-cell epitope identified in Pru p 3, Pru p 3(65-80), is a good candidate to develop new vaccines for hypersensitivity reactions associated with LTP allergens from Rosaceae fruits.
脂质转移蛋白（LTPs），尤其是桃子中的Pru p 3，是欧洲南部最主要的植物性食物过敏原，因此，对其过敏特性已进行了广泛研究。然而，在LTP泛过敏原家族的任何成员中，尚未对T细胞表位及其对患者T细胞反应的影响进行研究。本研究的目的是绘制Pru p 3的主要T细胞表位图谱，并评估其在桃子过敏患者与对照受试者中诱导的T细胞反应。因此，将18名桃子过敏患者的外周血单核细胞（PBMC）以及其中9人的Pru p 3特异性T细胞系（TCL）与Pru p 3和一组17种衍生肽（10肽，5个氨基酸重叠，代表Pru p 3的完整序列）一起培养。通过掺入氚化胸腺嘧啶核苷进行为期5天的增殖试验，同时通过TCL培养上清液的夹心酶联免疫吸附试验（ELISA）评估IL4和IFNγ的产生。将结果与10名非桃子过敏对照志愿者的结果进行比较。两个连续的肽显示出最高的激活能力。约74%的PBMC和TCL识别它们，形成一个单一的T表位：Pru p 3(65 - 80)。此外，还观察到其他特异性T细胞表位。超过60%的桃子过敏患者的TCL检测到Pru p 3(25 - 35)，而Pru p 3(45 - 55)仅激活对照受试者的PBMC。有趣的是，患者的TCL与Th2型相关，而对照TCL呈现Th1型细胞因子反应。在Pru p 3中鉴定出的主要免疫原性T细胞表位Pru p 3(65 - 80)，是开发与蔷薇科水果LTP过敏原相关的超敏反应新疫苗的良好候选物。
