IgE-Reactivity Pattern of Tomato Seed and Peel Nonspecific Lipid-Transfer Proteins after in Vitro Gastrointestinal Digestion

The influence of gastrointestinal digestion on the immunological properties of three different nonspecific lipid-transfer proteins (nsLTPs) described in tomato fruit has been assessed using an in vitro system mimicking the stomach and intestine digestion conditions. Tomato peel/pulp nsLTP, Sola l 3, was degraded after digestion, although the immunoglobulin E (IgE) recognition of intact protein and a 10 kDa band were still observed after 30 min of duodenal digestion in the presence of phosphatidylcholine. The tomato seed nsLTP, Sola l 7, showed a higher stability than the other seed allergen, Sola l 6, during digestion. Sola l 7 showed an IgE immunoreactive 6.5 kDa band in immunoblotting analysis, retaining up to 7% of its IgE-binding capacity in inhibition ELISA test after 60 min of duodenal digestion and keeping intact its ability to activate basophils after digestion. These results suggest that the tomato seed allergen Sola l 7 might be considered as an important allergen in the induction of allergic responses to tomato due to its high stability against gastrointestinal digestion.