1887

Abstract

Melanins, or melanin-like compounds, may play a role in the pathogenesis of a number of human fungal infections. This study investigated the production of melanin by the important opportunistic pathogen . Conidia from were harvested and treated with proteolytic enzymes, denaturant and hot, concentrated acid; this yielded dark particles which were similar in size and shape to the original propagules. Electron spin resonance spectroscopy revealed that the conidial-derived particles were stable free radicals consistent with an identification as melanin. Melanin particles were used to immunize BALB/c mice in order to produce a total of five anti-melanin monoclonal antibodies (mAbs). The latter mAbs were strongly reactive both with intact conidia and with extracted melanin particles by ELISA and immunofluorescence reactivity. Immunofluorescence labelling with the novel mAbs was used to examine the temporal expression of melanin during culture of –melanization was confined to conidial structures and was absent from hyphae. SDS-PAGE -3,4-dihydroxyphenylalanine (-DOPA) substrate analysis confirmed the presence of a laccase-type activity in conidial extracts, but not in hyphae. Melanin-binding mAbs were used to detect the presence of melanized conidia in three patients with nasal aspergilloma, indicating that melanization may occur during infection.

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2004-03-01
2024-12-04
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References

  1. Brakhage A. A., Langfelder K., Wanner G., Schmidt A., Jahn B. 1999; Pigment biosynthesis and virulence. Contrib Microbiol 2:205–215
    [Google Scholar]
  2. Casadevall A., Rosas A. L., Nosanchuk J. D. 2000; Melanin and virulence in Cryptococcus neoformans . Curr Opin Microbiol 3:354–358 [CrossRef]
    [Google Scholar]
  3. Enochs W. S., Nilges M. J., Swartz H. M. 1993; A standardized test for the identification and characterization of melanin using electron paramagnetic resonance (EPR) spectroscopy. Pigment Cell Res 6:91–99 [CrossRef]
    [Google Scholar]
  4. Gómez B. L., Nosanchuk J. D., Díez S., Youngchim S., Aisen P., Cano L. E., Restrepo A., Casadevall A., Hamilton A. J. 2001; Detection of melanin-like particles in the dimorphic fungal pathogen Paracoccidioides brasiliensis in vitro and during infection. Infect Immun 69:5760–5767 [CrossRef]
    [Google Scholar]
  5. Hamilton A. J., Holdom M. D. 1999; Antioxidant systems in the pathogenic fungi of man and their role in virulence. Med Mycol 37:375–389 [CrossRef]
    [Google Scholar]
  6. Hamilton A. J., Bartholomew M. A., Fenelon L., Figueroa J., Hay R. J. 1990a; Preparation of monoclonal antibodies that differentiate between Histoplasma capsulatum variant capsulatum and H.capsulatum variant duboisii . Trans R Soc Trop Med Hyg 84:425–428 [CrossRef]
    [Google Scholar]
  7. Hamilton A. J., Bartholomew M. A., Fenelon L. E., Figueroa J., Hay R. J. 1990b; A murine monoclonal antibody exhibiting high species specificity for Histoplasma capsulatum var. capsulatum . J Gen Microbiol 136:331–335 [CrossRef]
    [Google Scholar]
  8. Jahn B., Koch A., Schmidt A., Wanner G., Gehringer H., Bhakdi S., Brakhage A. A. 1997; Isolation and characterization of a pigmentless-conidium mutant of Aspergillus fumigatus with altered conidia surface and reduced virulence. Infect Immun 65:5110–5117
    [Google Scholar]
  9. Jahn B., Boukhallouk F., Lotz J., Langfelder K., Wanner G., Brakhage A. A. 2000; Interaction of human phagocytes with pigmentless Aspergillu s conidia. Infect Immun 68:3736–3739 [CrossRef]
    [Google Scholar]
  10. Langfelder K., Jahn B., Gehringer H., Schmidt A., Wanner G., Brakhage A. A. 1998; Identification of a polyketide synthase gene ( pksP ) of Aspergillus fumigatus involved in conidial pigment biosynthesis and virulence. Med Microbiol Immunol 187:79–89 [CrossRef]
    [Google Scholar]
  11. Langfelder K., Philippe B., Jahn B., Latge J. P., Brakhage A. A. 2001; Differential expression of the Aspergillus fumigatus pksP gene detected in vitro and in vivo with green fluorescent protein. Infect Immun 69:6411–6418 [CrossRef]
    [Google Scholar]
  12. Langfelder K., Streibel M., Jahn B., Haase G., Brakhage A. A. 2003; Biosynthesis of fungal melanins and their importance for human pathogenic fungi. Fungal Genet Biol 38:143–158 [CrossRef]
    [Google Scholar]
  13. Latgé J. P. 1999; Aspergillus fumigatus and aspergillosis. Clin Microbiol Rev 12:310–315
    [Google Scholar]
  14. Latgé J. P. 2001; The pathobiology of Aspergillus fumigatus . Trends Microbiol 9:382–389 [CrossRef]
    [Google Scholar]
  15. Morris-Jones R., Youngchim S., Gómez B. L., Aisen P., Hay R. J., Nosanchuk J. D., Casadevall A., Hamilton A. J. 2003; Synthesis of melanin-like pigment by Sporothrix schenckii in vitro and during mammalian infection. Infect Immun 71:4026–4033 [CrossRef]
    [Google Scholar]
  16. Nosanchuk J. D., Casadevall A. 2003; Budding of melanized Cryptococcus neoformans in the presence or absence of l-dopa. Microbiology 149:1945–1951 [CrossRef]
    [Google Scholar]
  17. Nosanchuk J. D., Rosas A. L., Lee S. C., Casadevall A. 2000; Melanization of Cryptococcus neoformans in human brain tissue. Lancet 355:2049–2050 [CrossRef]
    [Google Scholar]
  18. Nosanchuk J. D., Gómez B. L., Youngchim S., Díez S., Aisen P., Zancopé-Olivera R. M., Restrepo A., Casadevall A., Hamilton A. J. 2002; Histoplasma capsulatum synthesizes melanin-like pigments in vitro and during mammalian infection. Infect Immun 70:5124–5131 [CrossRef]
    [Google Scholar]
  19. Read S. M., Northcote D. H. 1981; Minimization of variation in the response to different proteins of the Coomassie blue G dye-binding assay for protein. Anal Biochem 116:53–64 [CrossRef]
    [Google Scholar]
  20. Romero-Martinez R., Wheeler M., Guerrero-Plata A., Rico G., Torres-Guerrero H. 2000; Biosynthesis and functions of melanin in Sporothrix schenckii . Infect Immun 68:3696–3703 [CrossRef]
    [Google Scholar]
  21. Rosas A. L., Nosanchuk J. D., Feldmesser M., Cox G. M., McDade H. C., Casadevall A. 2000a; Synthesis of polymerized melanin by Cryptococcus neoformans in infected rodents. Infect Immun 68:2845–2853 [CrossRef]
    [Google Scholar]
  22. Rosas A. L., Nosanchuk J. D., Gómez B. L., Edens W. A., Henson J. M., Casadevall A. 2000b; Isolation and serological analyses of fungal melanins. J Immunol Methods 244:69–80 [CrossRef]
    [Google Scholar]
  23. Tomee J. F. C., van der Werf T. S. 2001; Pulmonary aspergillosis. Neth J Med 59:244–258 [CrossRef]
    [Google Scholar]
  24. Tsai H. F., Washburn R. G., Chang Y. C., Kwon-Chung K. J. 1997; Aspergillus fumigatus arp1 modulates conidial pigmentation and complement deposition. Mol Microbiol 26:175–183 [CrossRef]
    [Google Scholar]
  25. Tsai H. F., Chang Y. C., Washburn R. G., Wheeler M. H., Kwong-Chung K. J. 1998; The developmentally regulated alb1 gene of Aspergillus fumigatus : its role in modulation of conidial morphology and virulence. J Bacteriol 180:3031–3038
    [Google Scholar]
  26. Tsai H. F., Wheeler M. H., Chang Y. C., Kwon-Chung K. J. 1999; A developmentally regulated gene cluster involved in conidial pigment biosynthesis in Aspergillus fumigatus . J Bacteriol 181:6469–6477
    [Google Scholar]
  27. Wang Y., Aisen P., Casadevall A. 1995; Cryptococcus neoformans melanin and virulence: mechanism of action. Infect Immun 63:3131–3136
    [Google Scholar]
  28. Watanabe A., Fujii I., Tsai H. F., Chang Y. C., Kwon-Chung K. J., Ebizuka Y. 2000; Aspergillus fumigatus alb1 encodes naphthopyrone synthase when expressed in Aspergillus oryzae . FEMS Microbiol Lett 192:39–44 [CrossRef]
    [Google Scholar]
  29. Wheeler M. H. 1983; Comparisons of fungal melanin biosynthesis in an ascomycetous, imperfect and basidiomycetous fungi. Trans Br Mycol Soc 81:29–36 [CrossRef]
    [Google Scholar]
  30. Zola H., Brooks D. 1982; Techniques for the production and characterization of monoclonal hybridoma antibodies. In Monoclonal Hybridoma Techniques and Applications pp 1–57 Edited by Hurrell J.G. Boca Raton, FL: CRC Press;
    [Google Scholar]
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