Molecular characterization of Api g 1, the major allergen of celery (Apium graveolens), and its immunological and structural relationships to a group of 17-kDa tree pollen allergens.
Individuals suffering from immediate hypersensitivity (type-I allergy) to a particular pollen frequently display intolerance to several foods of plant origin. In this respect, individuals sensitized to birch pollen and/or mugwort pollen frequently display type-I allergic symptoms after ingestion of celery. In this study, we expressed the major allergenic protein of celery, Api g 1, which is responsible for the birch-celery syndrome, in the form of a non-fusion protein. The open reading frame of the cDNA of Api g 1 codes for a protein of 153 amino acids with a molecular mass of 16.2 kDa and 40% identity (60% similarity) to the major allergen of birch pollen, Bet v 1. Furthermore, Api g 1 exhibited similar characteristics to (a) two proteins in parsley induced by fungal infection, (b) the major tree pollen allergens and (c) pathogenesis-related and stress-induced proteins in other plant species. The reactivity of recombinant Api g 1 with IgE antibodies present in sera from celery intolerant patients was comparable to that of the natural celery allergen. Cross-reactivity with Bet v 1 was proven by cross-inhibition experiments, which provides further support for the existence of the birch-celery syndrome and for the suggestion that allergies to some vegetable foods are epiphenomena to allergies caused by inhalation of tree pollen.
Breiteneder
H
H
Institute of General and Experimental Pathology, University of Vienna, Austria.
Hoffmann-Sommergruber
K
K
O'Riordain
G
G
Susani
M
M
Ahorn
H
H
Ebner
C
C
Kraft
D
D
Scheiner
O
O
D000485:Allergens / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D011058:Pollen / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000276:immunology
D000485:Allergens; D052179:Antigens, Plant; C096695:Api g 1 protein, Apium graveolens; D018076:DNA, Complementary; D010940:Plant Proteins; D011994:Recombinant Proteins