Rabbits that had been infected intravenously with conidiospores of Aspergillus fumigatus were used as sources of antibody for screening a lambda phage
cDNA expression library. The
cDNA was derived from A. fumigatus
mRNA that had been extracted from newly formed, germling hyphae. Thirty-six
antigens were identified using
antisera from six rabbits. Though many of these
antigens were expected to be intracellular
proteins because their genes did not encode a
signal sequence, the
antisera showed consistently a stronger immunoblot reaction with a cell fraction enriched for the fungal cell wall than with a fraction of predominantly intracellular components.
Antibodies to eight
antigens, including the glycosylhydrolase
Asp f 16, were produced by more than one rabbit. In current
vaccine studies,
Asp f 16 is the only single
antigen which has been reported to be capable of inducing protection against invasive
aspergillosis in mice.
Enolase and Aspergillus HSP90 were detected also; their homologues in Candida albicans have been tested as
vaccines and have been reported to provide a partially protective response against
invasive candidiasis in mice. The Aspergillus
antigens reported here may have value both in diagnostic tests for different forms of
aspergillosis and as
vaccine candidates for protection against invasive disease.