title: Molecular characterization of an autoallergen, Hom s 1, identified by serum IgE from atopic dermatitis patients.
abstract: Atopy is a genetically determined disorder that affects 10%-20% of the population. Many symptoms of patients with atopy (allergic rhinitis, conjunctivitis, asthma, and anaphylaxis) result from events occurring after crosslinking of cell-bound IgE by per se innocuous environmental antigens. The frequently raised hypothesis that autosensitization can also be a pathogenetic factor in atopy, gained support by our recent demonstration of IgE antibodies against human proteins in atopic dermatitis patients. To unravel the molecular nature of IgE-defined autoantigens, we used serum IgE from atopic dermatitis patients to screen a human epithelial cDNA expression library. One of the cDNA-encoding IgE-reactive products contained 1501 bp of a 2274 bp open-reading frame finally identified by sequence analysis of two additional cDNA clones resulting from oligonucleotide screening. The IgE-defined autoantigen, designated Hom s 1, exhibited an almost complete sequence identity with a recently described antigen recognized by cytotoxic T cells of a squamous cell carcinoma patient. Purified recombinant Hom s 1 specifically bound IgE from patients with severe atopy. When used as immunogen in rabbits, recombinant Hom s 1 gave rise to an anti-serum that reacted with a cytoplasmic protein exhibiting a broad cellular and tissue reactivity (skin, lung >> gastrointestinal tract >> muscle, brain) and identified a 55 kDa protein in blotted serum IgE preparations. The attractive possibility remains that the Hom s 1-triggered IgE response contributes to the events resulting in allergic tissue inflammation. If so, the respective recombinant molecule may serve as a paradigmatic tool for the diagnosis and treatment of patients with "intrinsic" atopy.
authors.affiliation: Institute of General and Experimental Pathology, Vienna General Hospital, University of Vienna Medical School, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Valenta
authors.forename: S
authors.initials: S
authors.lastname: Natter
authors.forename: S
authors.initials: S
authors.lastname: Seiberler
authors.forename: S
authors.initials: S
authors.lastname: Wichlas
authors.forename: D
authors.initials: D
authors.lastname: Maurer
authors.forename: M
authors.initials: M
authors.lastname: Hess
authors.forename: M
authors.initials: M
authors.lastname: Pavelka
authors.forename: M
authors.initials: M
authors.lastname: Grote
authors.forename: F
authors.initials: F
authors.lastname: Ferreira
authors.forename: Z
authors.initials: Z
authors.lastname: Szepfalusi
authors.forename: P
authors.initials: P
authors.lastname: Valent
authors.forename: G
authors.initials: G
authors.lastname: Stingl
mesh_terms: D000485:Allergens / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D001324:Autoantigens / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification*; D001483:Base Sequence; D002135:Calcium-Binding Proteins; D027682:Cation Transport Proteins; D003876:Dermatitis, Atopic / Q000097:blood / Q000276:immunology*; D000939:Epitopes; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood* / Q000276:immunology*; D033681:Mitochondrial Membrane Transport Proteins; D008969:Molecular Sequence Data; D013347:Subcellular Fractions / Q000737:chemistry / Q000276:immunology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D001324:Autoantigens; D002135:Calcium-Binding Proteins; D027682:Cation Transport Proteins; D000939:Epitopes; C116241:MICU1 protein, human; D033681:Mitochondrial Membrane Transport Proteins; D007073:Immunoglobulin E