Interaction of Non-Specific Lipid-Transfer Proteins With Plant-Derived Lipids and Its Impact on Allergic Sensitization

Abstract

Non-specific lipid-transfer proteins (nsLTPs) represent a family of ubiquitous plant proteins belonging to the prolamin superfamily. nsLTPs are characterized by a globular α-helical structure stabilized by four disulfide bonds and a hydrophobic cavity which acts as ligand-binding site for a broad spectrum of lipids and hydrophobic molecules. nsLTPs are involved in membrane biogenesis and in the adaption of plants to abiotic and biotic stress. They display antimicrobial activity by the ability to permeabilize the cell membrane of phytopathogens. Moreover, in the presence of lipids, nsLTPs are suggested to activate the plant immune system by a receptor-dependent mechanism. Additionally, nsLTPs from pollen and plant-derived food, in particular type 1 nsLTPs (9 kDa), are described as potent allergens. Within the nsLTP family Pru p 3 from peach is the clinically most relevant allergen which can cause genuine food allergy and frequently elicits severe clinical reactions. So far, the allergenic properties of nsLTPs are attributed to both their low molecular mass and their high thermal and proteolytic stability which allow them to reach the immune system in a biological intact form. Recently, the interaction of nsLTPs with lipids has been suggested to increase their allergenic properties and to promote the allergic sensitization to these proteins. This review will summarize the current knowledge on diversity of lipid ligands of plant LTPs, and illustrate recent studies performed with allergenic nsLTPs to investigate the effect of lipid binding on the structural modification and IgE-binding properties of proteins, and finally the potential effect on the innate immune responses.

Hydrophobic ligands influence the structure, stability, and processing of the major cockroach allergen Bla g 1

“…In addition to the innate immunomodulatory properties of these ligands phospholipids vesicles and other hydrophobic ligands can also influence sensitization through modulating protein stability. In previous studies, this effect was primarily manifested through an increased resistance to gastric digestion, and extended the length of time for which allergens can persist in the environment, and thus the likelihood of immune exposure 42,43 . While this is an important contributor to immunogenicity, our study of Bla g 1 suggests a role for fold stability in endosomal processing.…”

Lipophilic Allergens, Different Modes of Allergen-Lipid Interaction and Their Impact on Asthma and Allergy

“…A detailed review on LTPs was published in the special issue of Frontiers in Immunology, Role of Lipids in the Dynamics of Allergic Airway Inflammation by Scheurer and Schülke (38). We chose Pru p 3 to include an exemplified report on LTPs in the context of our own review.…”

Modern concept of pathogenesis of atopic diseases

“…В связи с этим, способность аллергена проникать через тканевые барьеры увеличивает его активирующие влияния на рецепторный аппарат клеток врождённой иммунной системы и, следовательно, повышает вероятность сенсибилизации [2,17,19,20,21]. Многие из аллергенов обладают такой способностью (аллергены с протеазной активностью, липид-транспортные белки и другие) [20,22,23,24]. Повышенная проницаемость кожи и слизистых оболочек для аллергенов может быть связана и с врождёнными дефектами барьерных тканей, а иногда и с их незрелостью в детском возрасте.…”