Thaumatin-Like Protein (Pru av 2) Is a Cherry Allergen That Triggers Percutaneous Sensitization in Mice

Numerous recent studies have suggested that food allergens enter the skin and predispose individuals to food allergies through the production of IgE antibodies in the body. Cherries are a popular fruit eaten worldwide. However, cherries are an allergenic food and percutaneous sensitization with cherry allergens through the perioral region may occur while ingesting cherries. The identity of the cherry protein that triggers percutaneous sensitization in humans or animal models remains unknown. In this study, the backs of BALB/c mice were shaved and crude cherry extracts containing sodium dodecyl sulfate were applied to the skin. Thereafter, the cherry-specific IgE and IgG1 antibodies generated and secreted in response to the epidermal application were measured using an enzyme-linked immunosorbent assay or immunoblotting. Skin exposure to cherry extracts elevated cherry-specific IgG1 levels. Application of fractionated and purified cherry proteins (antigen candidates for percutaneous sensitization) that bound to the IgG1 antibodies led to the identification of a thaumatin-like protein (Pru av 2). This molecule is known as the major cherry allergen that affects humans. In conclusion, our study identified Pru av 2 as a cherry allergen that triggers percutaneous sensitization in mice for the first time.