Isolation, cloning and allergenic reactivity of natural profilin Cit s 2, a major orange allergen
Authors: López-Torrejón, G.1; Ibáñez, M. D.2; Ahrazem, O.1; Sánchez-Monge, R.1; Sastre, J.3; Lombardero, M.4; Barber, D.4; Salcedo, G.1
Source: Allergy, Volume 60, Number 11, November 2005 , pp. 1424-1429(6)
Publisher: Blackwell Publishing
Abstract:
Background: Orange is among the most widely consumed fruits, and among the plant food sources causing allergic reactions according to popular perception. However, its relevant allergenic components are virtually unknown. Profilin is a well-defined minor plant panallergen, showing prevalences around 30% in fruits and vegetables. Methods: Twenty-three orange-allergic patients were studied. Natural orange profilin, named Cit s 2, was purified by affinity chromatography and characterized by N-terminal amino acid sequencing, matrix-assisted laser desorption/ionization mass spectrometry analysis and isolation of its coding cDNA. Reactivity to Cit s 2 was analyzed in vivo by skin prick tests (SPT) and in vitro by IgE immunodetection, specific IgE determination in individual sera and enzyme-linked immunosorbent assay-inhibition assays. Results: The N-terminal amino acid sequence and molecular mass of natural Cit s 2, both fully in agreement with the complete amino acid sequence deduced from its coding cDNA, demonstrated its profilin nature. An unexpectedly high reactivity to Cit s 2 was found in vivo (78% of positive SPT responses) and in vitro (87% of sera from orange allergic patients had specific IgE to Cit s 2). The purified allergen inhibited around 50% of the IgE binding to an orange pulp extract. Conclusion: Orange profilin Cit s 2, unlike other plant food profilins, is a major and highly prevalent allergen.Keywords: citrus fruit; food allergy; fruit allergen; orange; profilin
Document Type: Research article
DOI: 10.1111/j.1398-9995.2005.00903.x
Affiliations: 1: Unidad de Bioquímica, Departamento de Biotecnología, E.T.S. Ingenieros Agrónomos 2: Servicio de Alergia, Hospital Universitario Niño Jesús 3: Servicio de Alergia, Fundación Jiménez Díaz 4: Departamento I+D, ALK-Abelló, Madrid, Spain

Click here for Page Help