Molecular cloning of plane pollen allergen Plaa3 and its utility as diagnostic marker for peach associated plane pollen allergy

作者：Wangorsch A; Larsson H; Messmer M; Garcia Moral A; Lauer I; Wolfheimer S; Schulke S; Bartra J; Vieths S; Lidholm J; Scheurer S^*

来源：Clinical and Experimental Allergy, 2016, 46(5): 764-774.

DOI：10.1111/cea.12721

• LTP syndrome
• peach allergy
• Plaa3
• plane pollen
• Platanus allergy
• Prup3

BackgroundNon-specific lipid transfer proteins (nsLTP) are considered to provoke allergic symptoms to plane tree pollen, which are frequently associated with peach allergy.
ObjectiveThe objective was to clone the cDNA of plane pollen nsLTP Plaa3, to characterize IgE-binding and allergenic potency of recombinant Plaa3 in comparison to its natural counterpart and peach nsLTP Prup3.
MethodsNatural Plaa3 was purified from plane pollen and analysed by mass spectrometry (MS). Recombinant Plaa3 was characterized by SDS-PAGE and CD spectroscopy. Specific IgE to extract, components of plane pollen and Prup3 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 invitro mediator release assays and IgE cross-reactivity by competitive ELISA.
ResultsTwo Plaa3 isoforms were identified. Recombinant Plaa3 showed high purity, structural integrity, IgE-binding capacity comparable to nPlaa3 and biological potency. Sensitization to plane pollen extract was confirmed in 24/25 plane pollen allergics. The frequency of sensitization to Plaa3 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 Plaa1. Plaa3 and Prup3 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 Prup3 than to Plaa3.
ConclusionSensitization to Plaa3 is relevant in a subgroup of plane pollen allergics with concomitant peach allergy. IgE testing with Plaa3 may serve as a marker to identify plane pollen allergic patients at risk of LTP-mediated food reactions and thereby improve invitro diagnostic procedures.

• 出版日期2016-5