title: Bell peppers (Capsicum annuum) express allergens (profilin, pathogenesis-related protein P23 and Bet v 1) depending on the horticultural strain.
abstract: BACKGROUND
  Little is known about the role of bell peppers in food allergy. We collected sera from 11 patients with food allergy to bell peppers to analyze bell pepper extracts for allergen composition.
  
  
  METHODS
  Proteins of mature fruits of eight horticultural strains of bell peppers were extracted and tested with patients' sera for IgE binding and with monoclonal and polyclonal antibodies in immunoblot.
  
  
  RESULTS
  Profilin was detected in bell pepper extracts by an anti-celery profilin antibody. It showed high IgE binding activity in all extracts, which could be inhibited by recombinant birch pollen profilin. Anti-birch pollen monoclonal antibody BIP3, directed against birch pollen proteins between 30 and 69 kD, bound to bell pepper antigens of comparable molecular weights. A homologue of the major birch pollen allergen Bet v 1 was detected in four of eight horticultural strains of bell peppers, and was shown to bind IgE in 1 of the 11 patients. A 23-kD allergen of bell peppers was shown to correspond to the 23-kD major paprika allergen by IgE absorption experiments. Its N-terminal sequence showed 100% identity to P23 from tomatoes.
  
  
  CONCLUSIONS
  The appearance of profilin in all and Bet v 1 in 50% of the tested horticultural strains indicates that bell peppers have to be considered potentially dangerous for Bet v 1- and profilin-sensitized patients. Moreover, in 4 of 8 horticultural strains of bell peppers a homologue of the osmotin-like protein P23 from tomatoes is responsible for substantial IgE binding. Contact with Bet v 1 and P23 homologues in bell peppers can therefore be minimized by avoidance of the respective horticultural strains.
authors.affiliation: Department of General and Experimental Pathology, University Hospital AKH, Vienna, Austria. erika.jensen-jarolim@akh-wien.ac.at
authors.forename: E
authors.initials: E
authors.lastname: Jensen-Jarolim
authors.forename: B
authors.initials: B
authors.lastname: Santner
authors.forename: A
authors.initials: A
authors.lastname: Leitner
authors.forename: R
authors.initials: R
authors.lastname: Grimm
authors.forename: O
authors.initials: O
authors.lastname: Scheiner
authors.forename: C
authors.initials: C
authors.lastname: Ebner
authors.forename: H
authors.initials: H
authors.lastname: Breiteneder
mesh_terms: D000328:Adult; D000485:Allergens / Q000096:biosynthesis* / Q000276:immunology*; D000595:Amino Acid Sequence; D002212:Capsicum / Q000145:classification / Q000276:immunology* / Q000378:metabolism*; D003285:Contractile Proteins; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008840:Microfilament Proteins / Q000096:biosynthesis* / Q000276:immunology*; D008875:Middle Aged; D008969:Molecular Sequence Data; D010936:Plant Extracts / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology; D010946:Plants, Medicinal; D011058:Pollen / Q000276:immunology; D051304:Profilins; D012967:Sodium Dodecyl Sulfate
chemical_list: D000485:Allergens; D003285:Contractile Proteins; D008840:Microfilament Proteins; D010936:Plant Extracts; D010940:Plant Proteins; D051304:Profilins; D012967:Sodium Dodecyl Sulfate; D007073:Immunoglobulin E