Use of recombinant mitogillin for improved serodiagnosis of Aspergillus fumigatus-associated diseases.
During human infection, Aspergillus fumigatus secretes a 18-kDa protein that can be detected as an immunodominant antigen in the urine of infected patients. Recently, this protein was shown to be mitogillin, a ribotoxin that cleaves a single phosphodiester bond of the 29S rRNA of eukaryotic ribosomes. We proved the immunogenic capacity of mitogillin in a rabbit animal model, indicating its usefulness as an antigen for serological diagnosis of invasive aspergillosis. The mitogillin gene from A. fumigatus was transferred from plasmid pMIT+ to expression vector pQE30 and expressed in Escherichia coli as a fusion protein. Purified recombinant mitogillin was recognized by serum immunoglobulin G (IgG) of polyclonal rabbit sera that were obtained by immunization with purified native mitogillin. Consequently, we developed an enzyme-linked immunosorbent assay for detection of IgG, IgM, and IgA antibodies to recombinant mitogillin. In serum samples of patients suffering from aspergilloma (AO; n = 32), invasive pulmonary aspergillosis (IPA; n = 42), or invasive disseminated aspergillosis (IDA; n = 40), a good correlation of production of IgG antibody against mitogillin and clinical disease was observed (for patients with AO, 100% [32 of 32] were positive; for patients with IPA, 64% [31 of 42] were positive; for patients with IDA, 60% [24 of 40] were positive). In contrast, positive titers for serum IgG and IgM antibodies against mitogillin were found in only 1.3% of the serum samples of healthy volunteers and positive titers for IgA antibody were found in only 1.0% of the serum samples of healthy volunteers (n = 307; specificity = 95.4%). These results indicate that recombinant mitogillin expressed in E. coli can be used for improvement of the serodiagnosis of A. fumigatus-associated diseases.
Weig
M
M
Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany. mweig@gwdg.de
Frosch
M
M
Tintelnot
K
K
Haas
A
A
Gross
U
U
Linsmeier
B
B
Heesemann
J
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens; D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood*; D000946:Antigens, Fungal / Q000276:immunology; D052179:Antigens, Plant; D001228:Aspergillosis / Q000175:diagnosis*; D001232:Aspergillus fumigatus / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005656:Fungal Proteins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology; D015203:Reproducibility of Results; D012260:Ribonucleases
C081947:ASPF1 protein, Aspergillus fumigatus; D000485:Allergens; D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D052179:Antigens, Plant; D005656:Fungal Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011994:Recombinant Proteins; C036196:MITF protein, Aspergillus restrictus; D012260:Ribonucleases