Identification of a plane pollen lipid transfer protein (Pla a 3) and its immunological relation to the peach lipid-transfer protein, Pru p 3

• Published in: Clinical and experimental allergy Vol. 37; no. 2; pp. 261 - 269
• Main Authors: Lauer, I., Miguel-Moncin, M. S., Abel, T., Foetisch, K., Hartz, C., Fortunato, D., Cistero-Bahima, A., Vieths, S., Scheurer, S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-02-2007; Blackwell
• Subjects: Allergens; Allergic diseases; Antigens, Plant - analysis; Antigens, Plant - immunology; Biological and medical sciences; Carrier Proteins - analysis; Carrier Proteins - immunology; Cross Reactions; Digestive allergic diseases; food allergy; Food Hypersensitivity - immunology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; histamine release; Humans; Immunopathology; lipid transfer protein; Medical sciences; plane pollen; Plant Proteins - analysis; Plant Proteins - immunology; Pru p 3; Prunus - immunology; Rhinitis, Allergic, Seasonal - immunology; Trees - immunology; Immunopathology; Food allergy; Rosaceae; Peach; histamine release; Prunus persica; Pru p 3; Histamine; Immunology; Dicotyledones; Lipid transfer protein; Angiospermae; plane pollen; Digestive diseases; Spermatophyta; Pollen
• ISSN: 0954-7894; 1365-2222
• DOI: 10.1111/j.1365-2222.2007.02653.x

Summary
Background
An association between plane tree pollen allergy and plant food allergy has been described, but the cross‐reacting allergens have not yet been identified. The aim of this study was the identification of homologous non‐specific lipid‐transfer proteins (nsLTPs) in plane pollen, and to investigate its immunological relationship with the peach LTP, Pru p 3.
Methods
Three different patient groups were recruited in Spain: 22 plane pollen‐allergic patients without food allergy (A), 36 plane pollen‐allergic patients with peach allergy (B) and 10 peach‐allergic patients without plane pollen allergy (C). Proteins from plane pollen extract were fractionated by ion‐exchange and reversed‐phase chromatography. Further methods applied were N‐terminal amino acid sequence analysis, immunoblotting, enzyme allergosorbent test, CAP and basophil histamine release assays.
Results
A 10 kDa IgE‐reactive protein was purified from plane pollen and identified as nsLTP. Pla a 3 was characterized as a minor allergen (27.3%) in plane pollen‐allergic patients without food allergy (A) and as a major allergen in plane pollen‐allergic patients with peach allergy (B) showing a prevalence of IgE‐reactivity of 63.8%. Group B contained patients sensitized to Pru p 3 without IgE‐reactivity to plane‐LTP (16.6%). By contrast, Pla a 3 IgE‐reactive patients without sensitization to Pru p 3 could be found (16.6%). The sera of patients sensitized to both LTPs (50%), Pla a 3 and Pru p 3, showed different biological activity in histamine release assay: depending on individual patient's sera tested, Pla a 3 showed a similar, a stronger or a weaker allergenic potency in comparison with Pru p 3.
Conclusions
Plane LTP is a major allergen in plane pollen‐allergic patients with peach allergy recruited in the Mediterranean area. The results of histamine release tests and different IgE‐binding profiles pointed towards the existence of species‐specific IgE epitopes. Likewise, no general conclusion on the sensitizer could be made.