Identification of the IgE-binding protein pommaclein, Pun g 7, in pomegranate fruit
Alessandri C, Tuppo L, Giangrieco I, Tamburrini M, Rafaiani C, Ciancamerla M, Mari A, Ciardiello MA
Allergy 72: 469-469. (2017)
Introduction:Pomegranate, Punica granatum L., is a temperate cli-mate species, mainly cultivated in the Mediterranean area, SouthernAsia, and in several countries of North and South America. The con-sumption of pomegranate is increasing as it is considered a health-promoting food. Nevertheless, it can trigger allergic reactions, some-times severe. The LTP, Pun g 1, is the only pomegranate allergenreported so far.Objectives:Aim of this study is the detection of still unknownallergens in Pomegranate fruit.Results:Pommaclein, was isolated from the fruit juice, identified bydirect protein sequencing and characterized as IgE-binding proteinby immunoblotting, dot blotting and FABER test. Nineteen patientswith a reliable clinical history of allergic reactions to pomegranatefruit and/or sensitization to Pru p 3 and Pru p 7 were selected forthis study. Pommaclein is a 7 kDa protein, registered in the Uni-protKB under the accession number C0HKC0. It displays high struc-tural similarities with the peach allergen Peamaclein, Pru p 7. Amongthe nine patients tested with Pru p 7 by SPT, four resulted IgE posi-tive to Pru p 7 and Pommaclein and one to Pommaclein only. Twopatients out of 19 were monosensitized to Pommaclein, whereasfour patients were positive to both pomegranate and peach homolo-gous proteins. When IgE were detected in parallel for Pru p 7 andPommaclein by FABER nanotech test, 16 sera out of 1751 werefound positive for the former and 6 for the latter.Conclusions:A new allergenic protein, Pommaclein, Pun g 7, wasidentified. It is a homolog of the peach allergen Pru p 7, but theimmunological properties of the pomegranate allergen are not com-pletely shared with those of the peach allergen. Pun g 7 can con-tribute to improve the allergy diagnosis to plant-derived foods andprofiling the allergic patient IgE reactivity using panel of homologousmolecules as already done for other allergen groups.
