Surface Activity as a Crucial Factor of the Biological Actions of Ole e 1, the Main Aeroallergen of Olive Tree (Olea europaea) Pollen

Abstract

Aeroallergens are airborne substances -mainly proteins- capable of triggering Th2-immune responses in respiratory allergies. They enter into the body through the upper airways, reaching the mucosa afterwards. Mucosae lining at the luminal side consists of an epithelial barrier completely covered by mucus and pulmonary surfactant. Both, pulmonary surfactant and plasma membrane of the epithelial cells represent two physiological phospholipid-based barriers where allergens first impact before triggering their biological effects. The interaction of allergens with lipids at relevant physiological surfaces could promote structural changes on the molecule, resulting on a potential modification of its allergenic properties. In this work, we have firstly described the surface and phospholipid interaction capabilities of the clinically relevant aeroallergen Ole e 1, the main allergen of olive tree pollen. By using epifluorescence microscopy of Langmuir transferred films, we observed that lipid-packed ordered domains may function as a preferential location for allergen to accumulate at the air-liquid interface, an effect that is abolished in the presence of cholestenone. The possible implications of phospholipid-interfacial effects in the modification of allergen structural and functional properties will be discussed.

Secondary Outcomes of the Ole e 1 Proteins Involved in Pollen Tube Development: Impact on Allergies

“…Ole e 1 is recognized as one of the most important causes of Type-I respiratory allergy in the Mediterranean basin, after Poaceae pollen incidence ( Davies et al., 2015 ). Their presence in the atmosphere is widely reported along the Mediterreanean basin and the boundary areas ( Galán et al., 2013 ; Moreno-Grau et al., 2016 ; Plaza et al., 2016 ), intruding into the body through the upper airways to reach the mucosa ( López-Rodríguez et al., 2016 ). Moisture and temperature conditions in the nasal mucosa of a sensitive patient are similar to the stigma conditions of a compatible female flower, which induces a great expression of Ole e 1 allergen prompting inflammatory disorders as an exacerbated T helper 2 (Th2)-type immune response against aeroallergens, usually inoffensive to most individuals ( Akdis and Akdis, 2007 ).…”

Allergens and their associated small molecule ligands—their dual role in sensitization

“…Ole e 7 was shown to adsorb to air‐liquid interfaces and effectively interact with pre‐formed lipid monolayers composed of negatively charged phospholipids and cholesterol 108 . Ole e 7 seemed to reverse the inhibitory effect on the surface adsorption of the pulmonary surfactant manifested by plasma proteins such as HSA and other clinically relevant allergens like Ole e 1 109 . This suggests that Ole e 7 transfers surfactant lipid components to the interface whose impact on the structure and function of the pulmonary epithelium has yet to be determined.…”

“…Ole e 7 was shown to adsorb to air-liquid interfaces and effectively interact with pre-formed lipid monolayers composed of negatively charged phospholipids and cholesterol 108. Ole e 7 seemed to reverse the inhibitory effect on the surface adsorption of the pulmonary surfactant manifested by plasma proteins such as HSA and other clinically relevant allergens like Ole e 1 109.…”

Lig v 1 structure and the inflammatory response to the Ole e 1 protein family

“…Recent studies showed the surfactant activity of Ole e 1 on epithelial cells 7 suggesting the biology of Ole e 1‐proteins could influence the development of allergy. Hence, we aimed to establish the effect of Lig v 1 in the activation of the inflammatory response by the innate immune system in the second part of this work.…”