Allergologia et Immunopathologia

Allergologia et Immunopathologia

Volume 46, Issue 5, September–October 2018, Pages 482-490
Allergologia et Immunopathologia

Original Article
Evaluation of serum IgE in peach-allergic patients with systemic reaction by using recombinant Pru p 7 (gibberellin-regulated protein)

https://doi.org/10.1016/j.aller.2018.02.007Get rights and content

Abstract

Background

Lipid transfer protein (LTP) is a major fruit allergen. It has, however, recently been revealed that the systemic reaction in peach-allergic patients is related not only to LTP (Pru p 3) but also to gibberellin-regulated protein (Pru p 7). We investigated recombinant Pru p 7 (rPru p 7) for its potential use in worldwide standardization for the diagnosis of peach allergy.

Methods

Natural Pru p 7 (nPru p 7) was purified from peach crude extract using a monoclonal antibody affinity column. Complementary DNA for Pru p 7 was cloned and expressed in Escherichia coli and Pichia pastoris. Serum immunoglobulin (Ig) E in peach-allergic patients was examined by enzyme-linked immunosorbent assay (ELISA) using nPru p 7 and rPru p 7 (E. coli product: erPru p 7 and P. pastoris product: prPru p 7).

Results

Peach-allergic patients (n = 27) were diagnosed and categorized into oral reaction (n = 10) or systemic reaction (n = 17). The nPru p 7 positivity based on serum IgE levels was 52% in the systemic-reaction group and 0% in the oral-reaction group (P < 0.05). In the systemic-reaction group, there was no significant difference in reactivity between nPru p 7 and prPru p 7, but the reactivity of erPru p 7 was significantly lower than those of nPru p 7 and prPru p 7 (P < 0.05).

Conclusions

We found that prPru p 7 exhibited reactivity in ELISA comparable to that of nPru p 7 for the diagnosis of peach allergy with systemic reaction.

Introduction

Peach (Prunus persica) allergy is one of the most common allergies in the Mediterranean region and has been reported in Japan.1, 2, 3, 4, 5, 6, 7 The number of reports of peach allergy concerning component-resolved diagnosis (CRD) has recently increased.8, 9, 10 CRD may be useful for clinical-type classification.6, 11 Although Pru p 3 is known to be a popular plant allergen component, some cases of systemic reaction (SR) cannot be explained by Pru p 3.6, 12, 13 Pru p 3 is typically present in the outer part of the peach, and it sometimes does not cause symptoms when the peeled peach is eaten.14 Tuppo reported Pru p 7 as a new peach allergen in Europe.15 In Japan, many peach-allergic patients with SRs have shown sensitivity to Pru p 7, although few patients have shown sensitivity to Pru p 3.6, 16 Therefore, the contribution of Pru p 7 to peach allergy should be revealed promptly and globally. However, it is very difficult to obtain Pru p 7 free from Pru p 3 because of their similar protein chemical properties.15, 17 Therefore, the development of recombinant Pru p 7 (rPru p 7) is an urgent issue for the advancement of Pru p 7 research and diagnosis.7, 18, 19 For the expression of recombinant proteins, P. pastoris is widely used.20, 21, 22, 23, 24, 25 Pokaj found that P. pastoris is superior to Escherichia coli as an expression system for the production of large quantities of soluble, properly folded, and biologically active rCor a 8 [hazelnut lipid transfer protein (LTP)].26

In this study, we comparatively examined serum immunoglobulin (Ig) E levels in peach-allergic patients by enzyme-linked immunosorbent assay (ELISA) using natural Pru p 7 (nPru p 7) and rPru p 7 (E. coli product: erPru p 7 and P. pastoris product: prPru p 7) purified using monoclonal antibody (mAb) columns.

Section snippets

Study participants

A total of 84 participants with fruit allergies (including allergies except peaches) were enrolled in the Fruits Allergy Component Study Group (http://www.fruit-allergy.jp/) from June 2014 to December 2015. After enrolment, we applied to the ethical review boards of each facility and examined only those who were approved after obtaining written informed consent. Exclusion criteria included participants who had no symptoms when they ate peach or those whose symptoms were unclear or not

Participants

We examined 27 participants who met the criteria (9 men and 18 women; age range, 7–54 years; median age, 13 years). The participants were classified into the SR (n = 17, 6 men and 11 women; age range, 7–21 years; median age, 12.5 years) and OR groups (n = 10, 3 men and 7 women; age range, 9–54 years; median age, 13 years) (Table 1).

All the participants were positive for the skin-prick test against peach. The level of the specific IgE to Bet v 1 in the OR group was significantly higher than that in

Discussion

Pru p 7 is an allergen found in peach and has recently been reported as a marker related to SRs to this fruit.6, 15 To use Pru p 7 as the target of CRD, its qualitatively, quantitatively, and economically stable supply is necessary. Therefore, we assessed rPru p 7 for potential use in the worldwide standardization of the diagnosis for peach allergy.

Pru p 7 is a 7-kDa cysteine-rich protein with 12 cysteines of 63 amino acids, which corresponds to 19% of the total residues.15 The rigid structure

Trial registration

Not applicable.

Funding source

None.

Conflict of interest

None.

Acknowledgements

We are grateful to the doctors of the Fruits Allergy Component Study Group for patient recruitment, Teshigawara from the Department of Pediatrics, Fujita Health University, for her technical support in the experiments, and Siemens for performing the measurement of IMMULITE® 2000 3gAllergy™ for allergen components.

References (32)

  • J. Cuesta-Herranz et al.

    Peach allergy pattern: experience in 70 patients

    Allergy

    (1998)
  • E.A. Pastorello et al.

    New allergens in fruits and vegetables

    Allergy

    (1998)
  • N. Inomata et al.

    Identification of peamaclein as a marker allergen related to systemic reactions in peach allergy

    Ann Allergy Asthma Immunol

    (2014)
  • D.G. Ebo et al.

    Sensitization profiles in birch pollen-allergic patients with and without oral allergy syndrome to apple: lessons from multiplexed component-resolved allergy diagnosis

    Clin Exp Allergy

    (2010)
  • R.E. Rossi et al.

    Systemic reactions to peach are associated with high levels of specific IgE to Pru p 3

    Allergy

    (2009)
  • M. Pascal et al.

    Lipid transfer protein syndrome: clinical pattern, cofactor effect and profile of molecular sensitization to plant-foods and pollens

    Clin Exp Allergy

    (2012)
  • 1

    FO contributed equally with YM to this work.

    View full text