RESUMEN
Pru p 3, one of the most representative proteins of the lipid transfer proteins (LTPs), is responsible for clinical allergic reactions to food of peach origin. The identification of Pru p 3 epitopes is not comprehensive due to different methods and principles of epitope screening. In addition, evaluation of the stability of the epitopes and the validation of the immunological key amino acids still need further research. Therefore, in the present study, an immune slot-blot microarray assay was performed to screen the epitopes from Pru p 3 overlapping peptide library, and a new epitope (P-1, AA1-16, ITCGQVSSALAPCIPY) was identified and two identified epitopes were deeply investigated (P-2, AA12-27, PCIPYVRGGGAVPPAC; P-3, AA23-38, VPPACCNGIRNVNNLA). The stability of these epitopes was then verified by thermal processing treatment and digestion experiments. Moreover, the key amino acids of the three identified epitopes were obtained by epitope amino acid mutation combined with slot-blot experiments. These findings may contribute to the further understanding of Pru p 3 and the prevention of peach allergy.
Asunto(s)
Hipersensibilidad a los Alimentos , Prunus persica , Prunus , Alérgenos/química , Aminoácidos/metabolismo , Antígenos de Plantas , Epítopos de Linfocito B/metabolismo , Humanos , Inmunoglobulina E , Proteínas de Plantas/química , Prunus persica/genéticaRESUMEN
Besides tropomyosin (TM) that is widely recognized as a major allergen in molluscs, a 99-kDa novel allergen (Rap v 2) was recently found in the sea snail Rapana venosa and identified as paramyosin (PM). However, the allergenic epitopes of PM in any molluscs have not been identified yet. In the present study, seven allergenic epitopes of Rap v 2 were identified by immunoinformatics tools, dot-blot inhibition assay, and basophil degranulation assay. Based on the analysis of PM and allergenic epitope amino acids, it was found that highly hydrophobic and positively charged amino acid residues play an important role in the formation of Rap v 2 epitopes. In addition, three potential critical amino acids that may account for TM and PM cross-reactivity in molluscs were found by sequence- and structure-based methods. These findings could be of major importance for improving the understanding of relevant paramyosin epitopes and the prevention and therapy of mollusc allergy.
Asunto(s)
Alérgenos , Tropomiosina , Aminoácidos , Animales , Epítopos , Inmunoglobulina ERESUMEN
Information on the antigenic repertoire, especially the IgE-binding epitopes of an allergen is important for understanding the allergen induced immune response and cross-reactivity, as well as for generating the hypoallergenic variants for specific component resolved immunotherapy/diagnosis (CRIT and CRD). Data on the IgE-binding epitopes of cat allergens are scarce. In this study, a novel IgE-binding epitope of the cat major allergen, Fel d 1, was identified. Mouse monoclonal antibody (MAb) specific to the Fel d 1 was produced. Computerized intermolecular docking was used for determining the residues of the Fel d 1 bound by the specific MAb. The presumptive surface exposed residues of the Fel d 1 intrigued by the MAb are located on the chain 1. They are: L34 and T37 (helix 1); T39 (between helices 1 and 2); P40, E42 and E45 (helix 2); R61, K64, N65 and D68 (helix 3); and E73 and K76 (helix 4). The MAb competed efficiently with the cat allergic patients' serum IgE for Fel d 1 binding in the competitive IgE binding assay, indicating allergenicity of the MAb epitope. The newly identified allergenic epitope of the Fel d 1 is useful in a design of the CRIT and CRD for cat allergy.