Non-specific lipid transfer proteins: a protein family in search of an allergenic pattern.

committee. Sequence identity between the three mature protein sequences is quite low, ranging from 66 to 68%. These isoforms demonstrated 62–65% sequence identity to Pru p 3. Interestingly, higher sequence identities were observed with Gossypium spp. (72%), Sorghum bicolor (67%) and Zea mays (66%). Although the study enrolled only a limited number of pomegranate-allergic patients (n = 6), surprisingly, a highly complex pattern of specific IgE recognition to pomegranate and peach nsLTP could be observed [4] . All pomegranate-allergic patients were additionally sensitized to Pru p 3 (CAP class 1–4) but, interestingly, 4 of the 6 tolerated peach ingestion, suggesting strongly that a clinical association of pomegranate and peach allergy is not mandatory. In fact, the observation that Pru p 3 did not inhibit IgE reactivity to Pun g 1 isoallergens for all tested patients’ sera suggests the existence of Pru p 3-unrelated epitopes. However, in order to unequivocally clarify the relevance of the newly identified Pun g 1 isoallergens, purified recombinant molecules should be tested, preferably in a functional assay (e.g. mediator release). In recent years, numerous IgE-binding nsLTPs have been identified and characterized to varying degrees. However, large-scale population studies including numerous nsLTPs from different sources are still lacking. The question of the primary sensitizer, in particular, has not been fully addressed. NsLTPs were shown to mediate: (1) type I plant food allergy [3] , (2) pollen allergy [5] , (3) pollen-food syndrome [6] and (4) food allergy leading to The globalized economy has facilitated the introduction of numerous novel foods into our diets. These are often exotic fruits and vegetables that are promoted due to claims of beneficial health properties. Among them, pomegranate (Punica granatum) , endemic to the Middle East and India, is now available throughout Europe partly due to promotion of its antioxidant activity. However, pomegranate has recently been shown to trigger immediate hypersensitivity including anaphylactic reactions [1, 2] . Molecular-based investigations on pomegranate extract show that nonspecific lipid transfer proteins (nsLTPs) are involved in the development of adverse reactions. Due to their compact fold, members of this protein family demonstrate a high resistance to thermal and gastric treatment and they are involved in local but also severe systemic allergic reactions predominantly affecting the Mediterranean population. NsLTPs are present in plant food and vegetables, but also in pollen and latex [3] . In an earlier study, two pomegranate nsLTP isoallergens were purified from the natural source showing divergent immunological properties [1] . A follow-up study by Bolla et al. [4] identified the primary sequence of pomegranate nsLTPs and their immunological behavior as well as analyzing the role of the major peach allergen, Pru p 3, as a main sensitizer. Using degenerated primers based on published nsLTP sequences, the authors identified three different full-length cDNA sequences, which were designated as Pun g 1.0101, Pun g 1.0201 and Pun g 1.0301 by the WHO/IUIS Allergen Nomenclature SubPublished online: July 10, 2014