IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zancopé-Oliveira, R. M.
Right arrow Articles by Deepe, G. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zancopé-Oliveira, R. M.
Right arrow Articles by Deepe, G. S., Jr.

 Previous Article  |  Next Article 

Infection and Immunity, April 1999, p. 1947-1953, Vol. 67, No. 4
0019-9567/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Molecular Cloning, Characterization, and Expression of the M Antigen of Histoplasma capsulatum

Rosely M. Zancopé-Oliveira,1,2,* Errol Reiss,2 Timothy J. Lott,2 Leonard W. Mayer,2 and George S. Deepe Jr.3

Laboratório de Micologia Médica, Hospital Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil,1 Centers for Disease Control and Prevention, Atlanta, Georgia,2 and University of Cincinnati College of Medicine, Cincinnati, Ohio3

Received 25 September 1998/Returned for modification 10 November 1998/Accepted 6 January 1999

The major diagnostic antigens of Histoplasma capsulatum are the H and M antigens, pluripotent glycoproteins that elicit both humoral and T-cell-mediated immune responses. These antigens may play a role in the pathogenesis of histoplasmosis. M antigen is considered immunodominant because antibodies against it are the first precipitins to arise in acute histoplasmosis and are commonly present during all phases of infection. The biological activity of monomolecular M antigen and its ability to elicit a protective immune response to H. capsulatum are largely unknown. A molecular approach was used to identify the biological nature of M antigen, including its purification from histoplasmin, partial digestion with proteinases, and reverse-phase high-performance liquid chromatography to separate the released peptides. The amino acid sequences of the purified peptides were obtained by Edman degradation, and using degenerate oligonucleotide primers for PCR, a 321-bp fragment of the gene encoding the M antigen was amplified from genomic H. capsulatum DNA. This fragment was used to screen an H. capsulatum genomic DNA library, leading to the isolation, cloning, and sequencing of the full-length gene. The M gene consists of 2,187-bp DNA encoding a protein of 80,719 Da, which has significant homology to catalases from Aspergillus fumigatus, Aspergillus niger, and Eimericella nidulans. A cDNA was generated by reverse transcription-PCR and cloned into the expression vector pQE40. The identity of the cloned, expressed protein was confirmed by Western blotting. The recombinant fusion protein was immunoreactive with monoclonal antibodies raised against M antigen, with polyclonal mouse anti-M antiserum, and with a serum sample from a patient with histoplasmosis. The gene encoding the major immunodominant M antigen of H. capsulatum is a presumptive catalase, and the recombinant protein retains serodiagnostic activity.

* Corresponding author. Mailing address: Laboratório de Micologia Médica do Hospital Evandro Chagas, Fundação Oswaldo Cruz, Av. Brasil 4365, Manguinhos, Rio de Janeiro 21045-900 Brazil. Phone: (55-21) 290-1943. Fax: (55-21) 590-9988. E-mail: zancope{at}fiocruz.br.

Infection and Immunity, April 1999, p. 1947-1953, Vol. 67, No. 4
0019-9567/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 1999 by the American Society for Microbiology. All rights reserved.