Identification and molecular characterization of allergenic non-specific lipid-transfer protein from durum wheat (Triticum turgidum).

Abstract

BACKGROUND:

Common wheat (Triticum aestivum) and durum wheat (T. turgidum) are both involved in Baker's asthma (BA) and food allergy (FA) including wheat-dependent exercise-induced asthma (WDEIA). However, allergens in durum wheat have not been described, and the over-expression of T. turgidum non-specific lipid-transfer protein (nsLTPs) is considered to increase resistance to phytopathogens.

OBJECTIVE:

To identify and assess the allergenicity of nsLTP from T. turgidum.

METHODS:

Recombinant T. turgidum nsLTP Tri tu 14 was generated and tested for structural integrity (circular dichroism-spectroscopy) and purity (SDS-PAGE). Thirty-two wheat allergic patients were enrolled: 20 Spanish patients (BA) with positive bronchial challenge to wheat flour, and 12 Italian patients (wheat FA/WDEIA) with positive double-blind placebo-controlled food challenge/open food challenge (OFC) to pasta. IgE values to wheat, Tri tu 14, Tri a 14 (T. aestivum) and Pru p 3 (P. persica) were determined by ImmunoCAP testing. Allergenic potency (in vitro mediator release) and IgE cross-reactivity were investigated.

RESULTS:

Tri tu 14 was found to share 49% and 52% amino acid identity with Tri a 14 and Pru p 3, respectively. Among 25 Tri a 14 CAP positive sera, 23 (92%) were reactive to wheat extract, 22 (88%) to Tri tu 14 and 20 (80%) to Pru p 3. The correlation between Tri a 14 and Tri tu 14 specific IgE levels was r = 0.97 (BA) and r = 0.93 (FA/WDEIA), respectively. FA/WDEIA patients showed higher specific IgE values to Tri tu 14 and Pru p 3 than BA patients. Tri tu 14 displayed allergenic activity by mediator release from effector cells and IgE cross-reactivity with Pru p 3. The degree of IgE cross-reactivity between the two wheat nsLTPs varied between individual patients.

CONCLUSIONS AND CLINICAL RELEVANCE:

Sensitization to Tri tu 14 likely appears to be more important in wheat FA/WDEIA than in BA. Over-expression of Tri tu 14 in wheat would represent a risk for patients with nsLTP-mediated FA.

• Authors: Hela Safi, Andrea Wangorsch, Jonas Lidholm, Faiçal Brini, Jelena Spiric, Hans-Peter Rihs, Stefan Vieths, Alicia Armentia, Laura Farioli, Araceli Diaz-Perales, Elide A Pastorello, Stephan Scheurer
• Journal: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology (Clin Exp Allergy) Vol. 49 Issue 1 Pg. 120-129 (01 2019) ISSN: 1365-2222 [Electronic] England
• PMID: 30199586 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: © 2018 John Wiley & Sons Ltd.

Chemical References

• Antigens, Plant
• Carrier Proteins
• Plant Proteins
• lipid transfer proteins, plant
• Immunoglobulin E

Topics

• Adult
• Antigens, Plant (immunology)
• Asthma (blood, diagnosis, immunology)
• Bronchial Provocation Tests
• Carrier Proteins (immunology)
• Cross Reactions
• Double-Blind Method
• Female
• Humans
• Immunoglobulin E (blood, immunology)
• Male
• Middle Aged
• Plant Proteins (immunology)
• Skin Tests
• Triticum (immunology)