ALLERGENS, IGE, MEDIATORS, INFLAMMATORY MECHANISMS

Background: Aspergillus fumigatus, a common environmental fungus, is r esponsible for a number of lung disorders, including allergy and infec tion, in human beings. For immunodiagnosis of these diseases, standard ized, pure, and relevant antigens are not currently available. Methods : A complementary DNA library of A. fumigatus was constructed with mes senger RNA isolated from 96-hour-old culture of the organism. Fusion p roteins expressed with the cDNA were characterized and evaluated. Resu lts: One of the clones, which reacted with both rabbit anti-A. fumigat us serum and a pool of sera from patients with allergic bronchopulmona ry aspergillosis, expressed a 65 kd protein of A. fumigatus. The recom binant protein reacted with immunoglobulin E and immunoglobulin G anti bodies in the sera from patients with allergic bronchopulmonary asperg illosis. The deduced amino acid sequence of the partially sequenced co mplementary DNA of the clone is homologous with the hsp 90 family of h eat shock proteins in human beings and other organisms. Conclusion: Th e immunodominant nature and the homology to human heat shock proteins suggest a possible role for this protein in protective immunity and au toimmunity.