Mechanisms underlying induction of allergic sensitization by Pru p 3.

BACKGROUND: Recently, the nature of the lipid-ligand of Pru p 3, one of the most common plant food allergens in southern Europe, has been identified as a derivative of the alkaloid camptothecin bound to phytosphingosine. However, the origin of its immunological activity is still unknown. OBJECTIVE: We sought to evaluate the role of the Pru p 3 lipid-ligand in the immunogenic activity of Pru p 3. METHODS: In vitro cultures of different cell types (monocyte-derived dendritic cells [moDCs], PBMCs [peripheral blood mononuclear cells] and epithelial and iNKT-hybridoma cell lines) have been used to determine the immunological capacity of the ligand, by measuring cell proliferation, maturation markers and cytokine production. To study the capacity of the lipid-ligand to promote sensitization to Pru p 3 in vivo, a mouse model of anaphylaxis to peach has been produced and changes in the humoral and basophil responses have been analysed. RESULTS: The lipid-ligand of Pru p 3 induced maturation of moDCsc and proliferation of PBMCs. Its immunological activity resided in the phytosphingosine tail of the ligand. The adjuvant activity of the ligand was also confirmed in vivo, where the complex of Pru p 3-ligand induced higher levels of IgE than Pru p 3 alone. The immunological capacity of the Pru p 3 ligand was mediated by CD1d, as maturation of moDCs was inhibited by anti-CD1d antibodies and Pru p 3-ligand co-localized with CD1d on epithelial cells. Finally, Pru p 3-ligand presented by CD1d was able to interact with iNKTs. CONCLUSIONS AND CLINICAL RELEVANCE: The Pru p 3 lipid-ligand could act as an adjuvant to promote sensitization to Pru p 3, through its recognition by CD1d receptors. This intrinsic adjuvant activity of the accompanying lipid cargo could be a general essential feature of the mechanism underlying the phenomenon of allergenicity.

Bronchial Challenge With Tri a 14 as an Alternative Diagnostic Test for Baker's Asthma.

BACKGROUND: Baker's asthma (BA) is the most prevalent occupational respiratory disease in developed countries. It is caused by inhalation of wheat dust in the working environment and affects 1%-10% of workers in the baking industry. Diagnosis of BA is based on bronchial challenge with wheat, a technique that carries a high risk for patients. The wheat lipid transfer protein Tri a 14 is a major allergen in BA. OBJECTIVE: The aim of our study was to characterize Tri a 14 as a marker of BA in order to prevent patients from having to undergo bronchial challenge with wheat. METHODS: The study population comprised 55 patients selected at the Rio Hortega Hospital, Valladolid, Spain. Patients with BA were diagnosed using a skin prick test (SPT) with wheat and Tri a 14 and bronchial challenge test (BCT) with wheat. Patients with food allergy had a clear clinical history of allergy to peach confirmed by positive SPT to peach extract and Pru p 3. RESULTS: All patients in the BA group had a positive SPT result with wheat (100%), and most had positive results with Tri a 14 (95%). A positive BCT result with Tri a 14 was also observed in 22 of 27 of the patients with BA (82%). The response to Tri a 14 was specifically associated with BA. CONCLUSION: Tri a 14 is a good marker of BA and can be used in SPT and BCT as an alternative diagnostic method, thus avoiding bronchial challenge with wheat and reducing the risk associated with this technique.

Bronchial challenge with Tri a 14 as an alternative diagnostic test for Baker’s asthma

Background: Baker's asthma (BA) is the most prevalent occupational respiratory disease in developed countries. It is caused by inhalation of wheat dust in the working environment and affects 1%-10% of workers in the baking industry. Diagnosis of BA is based on bronchial challenge with wheat, a technique that carries a high risk for patients. The wheat lipid transfer protein Tri a 14 is a major allergen in BA. Objective: The aim of our study was to characterize Tri a 14 as a marker of BA in order to prevent patients from having to undergo bronchial challenge with wheat. Methods: The study population comprised 55 patients selected at the Rio Hortega Hospital, Valladolid, Spain. Patients with BA were diagnosed using a skin prick test (SPT) with wheat and Tri a 14 and bronchial challenge test (BCT) with wheat. Patients with food allergy had a clear clinical history of allergy to peach confirmed by positive SPT to peach extract and Pru p 3. Results: All patients in the BA group had a positive SPT result with wheat (100%), and most had positive results with Tri a 14 (95%). A positive BCT result with Tri a 14 was also observed in 22 of 27 of the patients with BA (82%). The response to Tri a 14 was specifically associated with BA. Conclusion: Tri a 14 is a good marker of BA and can be used in SPT and BCT as an alternative diagnostic method, thus avoiding bronchial challenge with wheat and reducing the risk associated with this technique (AU)

Antecedentes: El asma del panadero (BA) es la enfermedad respiratoria ocupacional más frecuente en los países occidentales. Está causada por la inhalación diaria de harina de trigo en el entorno de trabajo, afectando entre 1-10% de los trabajadores de la industria panadera. El diagnóstico de BA se basa en la provocación bronquial con trigo, una técnica de alto riesgo para los pacientes. La proteína de transferencia de lípidos de trigo (LTP) Tri a 14 ha sido descrita como alérgeno principal en esta patología. Objetivo: El objetivo de nuestro estudio ha sido caracterizar Tri a 14 como marcador de BA, y así evitar la provocación bronquial con trigo en estos pacientes. Métodos: Para ello, se seleccionaron cincuenta y cinco pacientes en el Hospital Río Hortega de Valladolid, España. Resultados: Los pacientes diagnosticados con BA mostraron prueba cutánea (SPT) positiva a trigo (100%) y la mayoría también a Tri a 14 (95%). Todos ellos, fueron sometidos a provocación bronquial con Tri a 14, observándose un resultado positivo en 22/27 de los sujetos evaluados (82%). Conclusiones: En base a esto, se puede concluir que Tri a 14 es un buen marcador de BA, y podría ser utilizado en SPT y provocación bronquial como método diagnóstico, reduciendo el uso de la provocación bronquial con trigo y el riesgo asociado a esta técnica (AU)