Wangorsch A, Larsson H, Messmer M, García-Moral A, Lauer I, Wolfheimer S, Schülke S, Bartra J, Vieths S, Lidholm J, Scheurer S
VPr Research Group Molecular Allergology, Paul-Ehrlich-Institut, Langen, Germany.
ThermoFisher Scientific, Uppsala, Sweden.
Clin Exp Allergy. 2016 May;46(5):764-74. doi: 10.1111/cea.12721.
Non-specific lipid transfer proteins (nsLTP) are considered to provoke allergic symptoms to plane tree pollen, which are frequently associated with peach allergy.
The objective was to clone the cDNA of plane pollen nsLTP Pla a 3, to characterize IgE-binding and allergenic potency of recombinant Pla a 3 in comparison to its natural counterpart and peach nsLTP Pru p 3.
Natural Pla a 3 was purified from plane pollen and analysed by mass spectrometry (MS). Recombinant Pla a 3 was characterized by SDS-PAGE and CD spectroscopy. Specific IgE to extract, components of plane pollen and Pru p 3 was measured by ImmunoCAP in sera of patients allergic to either plane pollen (n = 10), peach (n = 15) or both (n = 15). Biological potency of the proteins was investigated by in vitro mediator release assays and IgE cross-reactivity by competitive ELISA.
Two Pla a 3 isoforms were identified. Recombinant Pla a 3 showed high purity, structural integrity, IgE-binding capacity comparable to nPla a 3 and biological potency. Sensitization to plane pollen extract was confirmed in 24/25 plane pollen allergics. The frequency of sensitization to Pla a 3 was 53% among patients allergic to both plane pollen and peach and 10% among plane pollen allergics tolerating peach where most patients were sensitized to Pla a 1. Pla a 3 and Pru p 3 showed strong bi-directional IgE cross-reactivity in patients allergic to peach and plane pollen, but not in peach allergics tolerating plane pollen. Levels of IgE-binding were generally higher to Pru p 3 than to Pla a 3.
Sensitization to Pla a 3 is relevant in a subgroup of plane pollen allergics with concomitant peach allergy. IgE testing with Pla a 3 may serve as a marker to identify plane pollen allergic patients at risk of LTP-mediated food reactions and thereby improve in vitro diagnostic procedures.
非特异性脂质转移蛋白（nsLTP）被认为会引发对悬铃木花粉的过敏症状，而这些症状常与桃过敏相关。
克隆悬铃木花粉nsLTP Pla a 3的cDNA，比较重组Pla a 3与其天然对应物及桃nsLTP Pru p 3的IgE结合能力和致敏效力。
从悬铃木花粉中纯化天然Pla a 3，并通过质谱（MS）分析。通过SDS-PAGE和圆二色光谱对重组Pla a 3进行表征。采用免疫捕获法检测对悬铃木花粉提取物、悬铃木花粉成分及Pru p 3的特异性IgE，检测对象为对悬铃木花粉过敏（n = 10）、桃过敏（n = 15）或两者均过敏（n = 15）的患者血清。通过体外介质释放试验研究蛋白质的生物学效力，通过竞争性ELISA研究IgE交叉反应性。
鉴定出两种Pla a 3亚型。重组Pla a 3显示出高纯度、结构完整性、与天然Pla a 3相当的IgE结合能力及生物学效力。在24/25例悬铃木花粉过敏患者中证实了对悬铃木花粉提取物的致敏。在对悬铃木花粉和桃均过敏的患者中，对Pla a 3的致敏频率为53%；在耐受桃的悬铃木花粉过敏患者中，该频率为10%，其中大多数患者对Pla a 1致敏。在对桃和悬铃木花粉过敏的患者中，Pla a 3和Pru p 3显示出强烈的双向IgE交叉反应性，但在耐受悬铃木花粉的桃过敏患者中未显示。一般来说，Pru p 3的IgE结合水平高于Pla a 3。
对Pla a 3的致敏在伴有桃过敏的悬铃木花粉过敏患者亚组中具有相关性。用Pla a 3进行IgE检测可作为一种标志物，用于识别有LTP介导的食物反应风险的悬铃木花粉过敏患者，从而改进体外诊断程序。
