Molecular and immunological characterization of Asp f 34, a novel major cell wall allergen of Aspergillus fumigatus

• Published in: Allergy (Copenhagen) Vol. 64; no. 8; pp. 1144 - 1151
• Main Authors: Glaser, A.G, Kirsch, A.I, Zeller, S, Menz, G, Rhyner, C, Crameri, R
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.08.2009; Blackwell Publishing Ltd; Blackwell
• Subjects: ABPA; Adult; Aged; Allergens - chemistry; Allergens - genetics; Allergens - immunology; Allergies; Amino Acid Sequence; Antibodies, Fungal - immunology; Antibody Specificity; Asp f 34; Aspergillosis, Allergic Bronchopulmonary - diagnosis; Aspergillosis, Allergic Bronchopulmonary - immunology; Aspergillus fumigatus; Aspergillus fumigatus - immunology; Asthma; Biological and medical sciences; Cell Division - immunology; Cell Wall - immunology; cell wall protein; Cloning, Molecular; Dermatology; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Fungal Proteins - chemistry; Fungal Proteins - genetics; Fungal Proteins - immunology; Fungi; Humans; Immunoglobulin E - immunology; Immunology; Leukocytes, Mononuclear - immunology; major allergen; Male; Medical sciences; Middle Aged; Molecular biology; Molecular Sequence Data; Molecular Weight; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - immunology; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Sequence Homology, Amino Acid; Skin Tests; Allergy; Immunopathology; F-Cell; Nucleotide sequence; Dermatology; ABPA; Cell wall; Protein; Fungi; Immunology; Asp f 34; major allergen; Fungi Imperfecti; cell wall protein; Aspergillus fumigatus; Allergen
• ISSN: 0105-4538; 1398-9995
• DOI: 10.1111/j.1398-9995.2009.02029.x

Although fungal spores have been recognized as triggers of respiratory allergy and asthma, only two allergenic fungal cell wall components have so far been described. Eighty-one sequences derived from an Aspergillus fumigatus cDNA library encoding putative allergens were examined for the presence of cell wall components. A new allergen (Asp f 34) was evaluated by Western blots, enzyme-linked immunosorbent assay (ELISA), peripheral blood mononuclear cell (PBMC) proliferation assays, and skin prick test (SPT). The cDNA encoding Asp f 34 contained an open reading frame predicting a protein of 185 amino acids with a molecular weight of 19.38 kDa, showing sequence homology to phiA, an essential protein for the formation of conidia in the genus Aspergillus. The recombinant Asp f 34 was binding IgE from sensitized individuals in Western blots. An ELISA survey showed that 94% of the ABPA and 46% of the A. fumigatus-sensitized individuals tested had Asp f 34-specific serum IgE. Asp f 34 induced allergen-specific proliferation exclusively of PBMCs from patients sensitized to the allergen. Eight patients with anti-Asp f 34 serum IgE tested reacted positively in SPT, whereas four A. fumigatus-sensitized individuals without Asp f 34-specific IgE and eight healthy controls scored negatively. A cell wall protein of the phialides of A. fumigatus was identified as a major allergen. Asp f 34 belongs to the Aspergillus-specific proteins of the phiA family and has relevant potential for a specific diagnosis of Aspergillus sensitization.