Contribution of Ara h 2 to peanut-specific, immunoglobulin E-mediated, cell activation
Contribution of Ara h 2 to peanut-specific, immunoglobulin E-mediated, cell activation
复制标题
DOI：
10.1111/j.1365-2222.2007.02701.x
复制
发表时间：
2007-05-01
影响因子：
6.1
通讯作者：
Dreskin, S. C.
中科院分区：
文献类型：
--
作者：
McDermott, R. A.;Porterfield, H. S.;Dreskin, S. C.
背景花生变应原Ara h 2是一种有效的花生变应原，但其对花生粗提物(CPE)交联IgE和激活肥大细胞的作用尚未得到严格的评价。目的研究Ara h 2对CPE效应功能的影响。用花生高度过敏受试者的IgE致敏的RBL SX-38细胞和自然致敏的嗜碱性粒细胞对假处理和Arah2去除的CPE进行了功能分析。结果含有抗Arah2 IgE的血清致敏SX-38细胞后，CPE的浓度增加，使SX-38细胞获得50%的最大脱颗粒(EC50)所需的CPE浓度增加。用10个血清池进行的检测显示，在Ara h2耗尽后，EC50有小幅但显著的增加(1.65+/-0.15倍；P<；0.05)，而7个单独血清的检测显示平均EC50也有类似的增加(1.7+/-0.2倍；P<；0.02)。抗花生IgE与Arah2结合的百分率与Arah2耗竭后CPE的EC50增加呈正相关(r=0.83；P<；0.02)。另一方面，对其中3例患者进行嗜碱性粒细胞组胺释放试验，结果表明Ara-h2对花生过敏原的清除作用不明显。结论基于Ara-h2能有效地交联IgE，Ara-h2是一种重要的花生过敏原。它能有效地从特定的血清中交联IgE的能力与该血清中抗Ara-h2的比例有关，但Ara-h2并不占CPE对所研究的任何血清的大部分效应活性。
Background Ara h 2 is a potent peanut allergen but its contribution to the ability of a crude peanut extract (CPE) to cross-link IgE and activate mast cells has not been rigorously evaluated.Objective To measure the contribution that Ara h 2 makes to the effector function of a CPE.Methods Ara h 2 was specifically removed from a CPE as demonstrated by immunoblots, 2D gels, and an inhibitory ELISA. Functional assays of sham-treated and Ara h 2-depleted CPEs were performed with RBL SX-38 cells sensitized with IgE from highly peanut-allergic subjects and with naturally sensitized basophils.Results Depletion of similar to 99% of the Ara h 2 from the CPE led to an increase in the concentration of the CPE necessary to give 50% of maximal degranulation (EC50) of the SX-38 cells following sensitization with sera that contain anti-Ara h 2 IgE. Assays with a pool of 10 sera showed a small but significant increase in the EC50 following depletion of Ara h 2 (1.65 +/- 0.15-fold; P < 0.05) and assays of seven individual sera showed a similar increase in the average EC50 (1.7 +/- 0.2-fold; P < 0.02). The percent of the anti-peanut IgE that binds Ara h 2 correlated with an increase in the EC50 of the CPE following depletion of Ara h 2 (r=0.83; P < 0.02). On the other hand, data from three of these patients studied with a basophil histamine release assay did not show a significant effect of depletion of Ara h 2.Conclusion Based on its ability to cross-link IgE effectively, Ara h 2 is clearly an important peanut allergen. Its ability to cross-link IgE effectively from a specific serum is related to the proportion of anti-Ara h 2 in that serum but Ara h 2 does not account for a majority of the effector activity of the CPE for any of the sera studied.