title: Identification of thaumatin-like protein and aspartyl protease as new major allergens in lettuce (Lactuca sativa).
abstract: METHODS
  Today, about 2-8% of the population of Western countries exhibits some type of food allergy whose impact ranges from localized symptoms confined to the oral mucosa to severe anaphylactic reactions. Consumed worldwide, lettuce is a Compositae family vegetable that can elicit allergic reactions. To date, however, only one lipid transfer protein has been described in allergic reaction to lettuce. The aim of this study was to identify potential new allergens involved in lettuce allergy.
  
  
  RESULTS
  Sera from 42 Spanish lettuce-allergic patients were obtained from patients recruited at the outpatient clinic. IgE-binding proteins were detected by SDS-PAGE and immunoblotting. Molecular characterization of IgE-binding bands was performed by MS. Thaumatin was purified using the Agilent 3100 OFFGEL system. The IgE-binding bands recognized in the sera of more than 50% of patients were identified as lipid transfer protein (9 kDa), a thaumatin-like protein (26 kDa), and an aspartyl protease (35 and 45 kDa). ELISA inhibition studies were performed to confirm the IgE reactivity of the purified allergen.
  
  
  CONCLUSIONS
  Two new major lettuce allergens-a thaumatin-like protein and an aspartyl protease-have been identified and characterized. These allergens may be used to improve both diagnosis and treatment of lettuce-allergic patients.
authors: Department of Immunology, IIS- Fundación Jimenez Diaz, Madrid.
authors: Esther
authors: E
authors: Muñoz-García
authors: Olga
authors: O
authors: Luengo-Sánchez
authors: Elisa
authors: E
authors: Haroun-Díaz
authors: Aroa Sanz
authors: AS
authors: Maroto
authors: Arancha
authors: A
authors: Palacín
authors: Araceli
authors: A
authors: Díaz-Perales
authors: Manuel
authors: M
authors: de las Heras Gozalo
authors: Moisés
authors: M
authors: Labrador-Horrillo
authors: Fernando
authors: F
authors: Vivanco
authors: Javier
authors: J
authors: Cuesta-Herranz
authors: Carlos
authors: C
authors: Pastor-Vargas
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D057055:Aspartic Acid Proteases / Q000276:immunology* / Q000302:isolation & purification; D003429:Cross Reactions / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D007073:Immunoglobulin E / Q000378:metabolism; D018545:Lactuca / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000276:immunology* / Q000302:isolation & purification; D027861:Prunus / Q000276:immunology; D055815:Young Adult
chemical_list: D000485:Allergens; D010940:Plant Proteins; D007073:Immunoglobulin E; C003427:thaumatin protein, plant; D057055:Aspartic Acid Proteases
keywords: Allergens; Aspartyl protease; Food allergy; Lettuce allergy; Thaumatin-like protein