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[The isolation and evaluation of Aspergillus fumigatus antigens]
V de S Lirio1, C M de Assis, M I Cano
1Laboratório de Micologia Médica, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Brasil.
Abstract:
Antigens from three strains of Aspergillus fumigatus (354, 356, and JIG) and an antiserum against the mixing of these antigens have been produced, and evaluated immunochemically. The antigens were obtained through a modified Coleman & Kaufman technique (culture filtrate concentrated by acetone). Analysis by the immunodiffusion test (ID) against homologous serum has yielded 100% sensitivity (with the studied sera). Concerning heterologous sera we found reactivity with a serum of a patient of candidiasis and another with histoplasmosis. The same result was obtained with a reference antigen in immunodiffusion, showing similar standards of response. Titration of the antiserum by ID and counterimmunoelectrophoresis showed a title of 1:32, and by complement fixation (micro-technique) a title of 1:128. Using immunoelectrophoresis (IEF), the produced antiserum yielded 8 lines of precipitation (5 in the anodic pole and 3 in the cathodic one). In SDS-PAGE at 12.5% the antigen has presented a rather complex electrophoretic profile (26 proteic subunits with a molecular weight ranging from 18 a > 100 kDa). Immunogenicity of the antigen was observed in all fractions of SDS-PAGE when the immunoblotting against the antiserum was carried out.
Insights
Researchers developed Aspergillus fumigatus antigens and an antiserum for immunochemical evaluation. This diagnostic tool showed high sensitivity and potential for detecting fungal infections.
Area of Science:
- Mycology
- Immunochemistry
- Medical Diagnostics
Background:
- Aspergillus fumigatus is an opportunistic fungal pathogen causing significant human disease.
- Accurate and sensitive diagnostic tools are crucial for timely treatment of invasive aspergillosis.
Purpose of the Study:
- To produce and immunochemically characterize antigens from Aspergillus fumigatus strains.
- To evaluate the diagnostic potential of these antigens and a corresponding antiserum.
Main Methods:
- Modified Coleman & Kaufman technique for antigen preparation.
- Immunodiffusion (ID), counterimmunoelectrophoresis, complement fixation (CF), and immunoelectrophoresis (IEF) for antiserum titration and characterization.
- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting to analyze antigen complexity and immunogenicity.
Main Results:
- Antigens from three Aspergillus fumigatus strains were successfully produced and concentrated.
- The produced antiserum demonstrated 100% sensitivity in immunodiffusion tests against homologous sera.
- Antiserum titration revealed high antibody titers (1:32 by ID, 1:128 by CF).
- Immunoelectrophoresis showed 8 precipitation lines, and SDS-PAGE revealed 26 protein subunits (18-100 kDa).
- All SDS-PAGE fractions exhibited immunogenicity via immunoblotting.
Conclusions:
- The study successfully produced and characterized Aspergillus fumigatus antigens and a specific antiserum.
- The developed reagents show high sensitivity and broad reactivity, indicating potential for diagnostic applications in fungal infections.
- Further validation is warranted to establish their clinical utility in diagnosing aspergillosis and related conditions.