Related Experiment Video
Updated: Oct 22, 2026
Passive Administration of Monoclonal Antibodies Against H. capsulatum and Others Fungal Pathogens
Published on: February 14, 2011
N-acetylated α-linked acidic dipeptidase is identified as an antigen of Histoplasma capsulatum
Takahito Toyotome1, Akira Watanabe2, Eri Ochiai3
1Research Unit for Risk Analysis, Diagnostic Center for Animal Health and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11, Inadacho, Obihiro, Hokkaido 080-8555, Japan; Division of Clinical Research, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba 260-8673, Japan.
Abstract:
Histoplasmosis, one of the most important mycoses, needs to be diagnosed rapidly and accurately. The main method used to diagnose histoplasmosis is serological detection of antibodies to the Histoplasma capsulatum H and M antigens. Several other protein antigens have been reported in H. capsulatum; however, they have not been used for diagnosis. In this study, we explored novel antigens that were detected during H. capsulatum infection. We obtained a protein mixture from H. capsulatum yeast cells after vigorous mixing in a 0.1% Triton X-100 solution. From the resultant pool, we detected nine spots that reacted with sera from patients with histoplasmosis and identified eight seroactive proteins with mass spectrometry. The seroactive proteins were purified, and their antigenicities were tested with an enzyme-linked immunosorbent assay (ELISA). ELISA revealed that the titer of the patients' sera to N-acetylated α-linked acidic dipeptidase was significantly higher than those of healthy volunteers (P < 0.01). These data indicate that N-acetylated α-linked acidic dipeptidase of H. capsulatum is recognized as a major antigen during histoplasmosis.
Insights
Diagnosing histoplasmosis requires identifying key fungal antigens. Researchers found N-acetylated α-linked acidic dipeptidase in Histoplasma capsulatum is a major antigen, improving diagnostic accuracy for this mycosis.
Area of Science:
- Medical Mycology
- Immunology
- Proteomics
Background:
- Histoplasmosis diagnosis relies on detecting antibodies to Histoplasma capsulatum H and M antigens.
- Existing diagnostic methods for this significant mycosis require rapid and accurate improvements.
- Novel protein antigens from H. capsulatum have potential for enhanced diagnostic applications.
Purpose of the Study:
- To explore and identify novel seroactive antigens from Histoplasma capsulatum.
- To evaluate the diagnostic potential of newly identified antigens in histoplasmosis.
- To investigate N-acetylated α-linked acidic dipeptidase as a key antigen.
Main Methods:
- Extraction of a protein mixture from H. capsulatum yeast cells using Triton X-100.
- Identification of seroactive proteins using mass spectrometry after reaction with patient sera.
- Purification and antigenic testing of identified proteins via enzyme-linked immunosorbent assay (ELISA).
Main Results:
- Eight seroactive proteins were identified from the H. capsulatum protein mixture.
- N-acetylated α-linked acidic dipeptidase showed significantly higher reactivity with sera from histoplasmosis patients compared to healthy volunteers (P < 0.01).
- ELISA confirmed the high antigenicity of N-acetylated α-linked acidic dipeptidase.
Conclusions:
- N-acetylated α-linked acidic dipeptidase is a major antigen recognized during histoplasmosis.
- This identified antigen holds significant promise for improving the serological diagnosis of histoplasmosis.
- Further research into novel antigens can enhance the accuracy and speed of mycosis diagnostics.
