Skip to main content

Histoplasma capsulatum 100-kilodalton antigen: recombinant production, characterization, and evaluation of its possible application in the diagnosis of histoplasmosis


The goal of the present work was to develop a novel reagent with potential for histoplasmosis diagnosis. For this purpose, the genetic sequence of the 100 kDa protein of Histoplasma capsulatum (Hcp100) was cloned and expressed as a secretory protein in Pichia pastoris. After optimizing the culture conditions and purifying by immobilized metal ion affinity chromatography, the highest yield of Hcp100 reached approximately 1.3 mg/l with > 90% purity in shake flasks using basal salt medium supplemented with casamino acids after 72 h of methanol induction. To investigate its potential for diagnosis, its detection in urine samples using specific polyclonal antibodies as reagent was evaluated by dot blot in 6 patients with progressive disseminated histoplasmosis (PDH), of whom all had AIDS. Antigen was detected in urine from all 6 (100%) PDH patients. Urine samples from a pool of 20 healthy individuals did not react with the anti-Hcp100 antibodies. The dot blot assay performed in this study provides preliminary data of a simple technology that can be performed in medical institutions with limited resources to facilitate the rapid diagnosis of histoplasmosis, particularly the disseminated forms. Hence, use of these assays may provide a rapid diagnostic tool of PDH in endemic areas for histoplasmosis where PDH-related mortality is high, hastening treatment and improving patient survival. Finally, this novel antigen and its specific antibodies may provide an alternative diagnostic reagent to the largely unknown and poorly characterized polysaccharide antigens (HPA, galactomannan, histoplasmin) frequently used in the diagnostic tests.

Key Points

  • Few antigens are used as laboratory tools for the immunodiagnosis of histoplasmosis.

  • P. pastoris was an excellent system for recombinant Hcp100 expression.

  • Maximum expression levels of rHcp100 were achieved in BSM with 1% casamino acids.

  • Dot blot assays with anti-rHcp100 antisera can be successfully used for diagnosing PHD.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6


Download references


This work was supported by the University of Buenos Aires (Grant UBACyT 20020130200222BA). DGM, ADN, and MLC are staff members of CONICET. MAT thanks the doctoral scholarship to CONICET.

Author information

Authors and Affiliations



All authors contributed to the study conception and design as well as to material preparation, data collection, and analysis. The first draft of the manuscript was written by MLC and ADN and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to María L. Cuestas.

Ethics declarations

This study was approved by the institutional review committee “Dr Vicente Federico Del Giúdice” at Hospital Nacional Alejandro Posadas, Buenos Aires, Argentina (Ref. 260 EMnP0S0/19). Informed consents were obtained from all participants. The procedures involving animals followed the NIH Guide for the Care and Use of Laboratory Animals and were approved by the Comité Institucional para el Cuidado y Uso de Animales de Laboratorio (CICUAL-FFyB, Protocol number 1018-19).

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material


(PDF 352 kb)

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Toscanini, M.A., Maglio, D.G., Capece, P. et al. Histoplasma capsulatum 100-kilodalton antigen: recombinant production, characterization, and evaluation of its possible application in the diagnosis of histoplasmosis. Appl Microbiol Biotechnol 104, 5861–5872 (2020).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: