Isolation and characterization of a recombinant heat shock protein of Aspergillus fumigatus.

BACKGROUND

Aspergillus fumigatus, a common environmental fungus, is responsible for a number of lung disorders, including allergy and infection, in human beings. For immunodiagnosis of these diseases, standardized, pure, and relevant antigens are not currently available.

METHODS

A complementary DNA library of A. fumigatus was constructed with messenger RNA isolated from 96-hour-old culture of the organism. Fusion proteins expressed with the cDNA were characterized and evaluated.

RESULTS

One of the clones, which reacted with both rabbit anti-A. fumigatus serum and a pool of sera from patients with allergic bronchopulmonary aspergillosis, expressed a 65 kd protein of A. fumigatus. The recombinant protein reacted with immunoglobulin E and immunoglobulin G antibodies in the sera from patients with allergic bronchopulmonary aspergillosis. The deduced amino acid sequence of the partially sequenced complementary DNA of the clone is homologous with the hsp 90 family of heat shock proteins in human beings and other organisms.

CONCLUSION

The immunodominant nature and the homology to human heat shock proteins suggest a possible role for this protein in protective immunity and autoimmunity.