Molecular allergology research has provided valuable information on the structure and function of single allergenic molecules. There are several
allergens in food and inhalant
allergen sources that are able to interact with
lipid ligands via different structural features: hydrophobic pockets, hydrophobic cavities, or specialized domains. For only a few of these
allergens information on their associated
ligands is already available. Several of the
allergens are clinically relevant, so that it is highly probable that the individual structural features with which they interact with
lipids have a direct effect on their allergenic potential, and thus on
allergy development. There is some evidence for a protective effect of
lipids delaying the enzymatic digestion of the peanut (Arachis hypogaea)
allergen Ara h 8 (hydrophobic pocket), probably allowing this molecule to get to the intestinal immune system intact (sensitization). Oleosins from different food
allergen sources are part of
lipid storage organelles and potential marker
allergens for the severity of the
allergic reaction. House dust mite (HDM), is more often associated with allergic
asthma than other sources of inhalant
allergens. In particular,
lipid-associated
allergens from Dermatophagoides pteronyssinus which are
Der p 2,
Der p 5,
Der p 7, Der p 13, Der p 14, and Der p 21 have been reported to be associated with severe
allergic reactions and respiratory symptoms such as
asthma. The exact mechanism of interaction of these
allergens with
lipids still has to be elucidated. Apart from single
allergens glycolipids have been shown to directly induce allergic
inflammation. Several-in parts conflicting-data exist on the
lipid (and
allergen) and
toll-like receptor interactions. For only few single
allergens mechanistic studies were performed on their interaction with the air-liquid interface of the lungs, in particular with the
surfactant components SP-A and
SP-D. The increasing knowledge on
protein-
lipid-interaction for lipophilic and hydrophobic food and inhalant
allergens on the basis of their particular structure, of their capacity to be integral part of membranes (like the oleosins), and their ability to interact with membranes,
surfactant components, and transport
lipids (like the
lipid transfer
proteins) are essential to eventually clarify
allergy and
asthma development.