1887

Abstract

The entomopathogenic fungus and its insect host target represent a model system with which to examine host–pathogen interactions. Carbohydrate epitopes on the surfaces of fungal cells play diverse roles in processes that include adhesion, non-self recognition and immune invasion with respect to invertebrate hosts. produces a number of distinct cell types that include aerial conidia, submerged conidia, blastospores and haemolymph-derived cells termed blastospores or hyphal bodies. In order to characterize variations in the surface carbohydrate epitopes among these cells, a series of fluorescently labelled lectins, combined with confocal microscopy and flow cytometry to quantify the response, was used. Aerial conidia displayed the most diverse lectin binding characteristics, showing reactivity against concanavalin A (ConA), (GNL), (GSII), (HPA), isolectin (GSI), peanut agglutinin (PNA), agglutinin I (UEAI) and wheatgerm agglutinin (WGA), and weak reactivity against I (RCA), (SNA), (LFA) and (SJA) lectins. Lectin binding to submerged conidia was similar to that to aerial conidia, except that no reactivity against UEAI, HPA and SJA was noted, and WGA appeared to bind strongly at specific polar spots. In contrast, the majority of blastospores were not bound by ConA, GNL, GSII, GSI, SNA, UEAI, LFA or SJA, with PNA binding in large patches, and some polarity in WGA binding noted. Significant changes in lectin binding also occurred after aerial conidial germination and in cells grown on either lactose or trehalose. For germinated conidia, differential lectin binding was noted between the conidial base, the germ tube and the hyphal tip. Fungal cells isolated from the haemolymph of the infected insect hosts and appeared to shed most carbohydrate epitopes, displaying binding only to the GNL, PNA and WGA lectins. Ultrastructural examination of the haemolymph-derived cells revealed the presence of a highly ordered outermost brush-like structure not present on any of the cells. Haemolymph-derived hyphal bodies placed into rich broth medium showed expression of several surface carbohydrate epitopes, most notably showing increased PNA binding and strong binding by the RCA lectin. These data indicate robust and diverse production of carbohydrate epitopes on different developmental stages of fungal cells and provide evidence that surface carbohydrates are elaborated in infection-specific patterns.

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2009-09-01
2024-03-29
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References

  1. Alves S. B., Rossi L. S., Lopes R. B., Tamai M. A., Pereira R. M. 2002; Beauveria bassiana yeast phase on agar medium and its pathogenicity against Diatraea saccharalis (Lepidoptera: Crambidae) and Tetranychus urticae (Acari: Tetranychidae. J Invertebr Pathol 81:70–77
    [Google Scholar]
  2. Bidochka M. J., Pfeifer T. A., Khachatourians G. G. 1987; Development of the entomopathogenic fungus Beauveria bassiana in liquid cultures. Mycopathologia 99:77–83
    [Google Scholar]
  3. Cho E. M., Liu L., Farmerie W., Keyhani N. O. 2006; EST analysis of cDNA libraries from the entomopathogenic fungus Beauveria ( Cordyceps) bassiana. I. Evidence for stage-specific gene expression in aerial conidia, in vitro blastospores and submerged conidia. Microbiology 152:2843–2854
    [Google Scholar]
  4. Esquenazi D., de Souza W., Alviano C. S., Rozental S. 2003; The role of surface carbohydrates on the interaction of microconidia of Trichophyton mentagrophytes with epithelial cells. FEMS Immunol Med Microbiol 35:113–123
    [Google Scholar]
  5. Hazen K. C., Hazen B. W. 1993; Surface hydrophobic and hydrophilic protein alterations in Candida albicans . FEMS Microbiol Lett 107:83–88
    [Google Scholar]
  6. Holder D. J., Keyhani N. O. 2005; Adhesion of the entomopathogenic fungus Beauveria ( Cordyceps) bassiana to substrata. Appl Environ Microbiol 71:5260–5266
    [Google Scholar]
  7. Holder D. J., Kirkland B. H., Lewis M. W., Keyhani N. O. 2007; Surface characteristics of the entomopathogenic fungus Beauveria ( Cordyceps) bassiana . Microbiology 153:3448–3457
    [Google Scholar]
  8. Latgé J. P. 2007; The cell wall: a carbohydrate armour for the fungal cell. Mol Microbiol 66:279–290
    [Google Scholar]
  9. Latgé J. P., Bouziane H., Diaquin M. 1988; Ultrastructure and composition of the conidial wall of Cladosporium cladosporioides . Can J Microbiol 34:1325–1329
    [Google Scholar]
  10. Latgé J. P., Kobayashi H., Debeaupuis J. P., Diaquin M., Sarfati J., Wieruszeski J. M., Parra E., Bouchara J. P., Fournet B. 1994; Chemical and immunological characterization of the extracellular galactomannan of Aspergillus fumigatus . Infect Immun 62:5424–5433
    [Google Scholar]
  11. Lewis M. W., Robalino I. V., Keyhani N. O. 2009; Uptake of the fluorescent probe FM4-64 by hyphae and haemolymph-derived in vivo hyphal bodies of the entomopathogenic fungus Beauveria bassiana . Microbiology 155:3110–3120
    [Google Scholar]
  12. Lis H., Sharon N. 1986; Lectins as molecules and as tools. Annu Rev Biochem 55:35–67
    [Google Scholar]
  13. Masuoka J. 2004; Surface glycans of Candida albicans and other pathogenic fungi: physiological roles, clinical uses, and experimental challenges. Clin Microbiol Rev 17:281
    [Google Scholar]
  14. Osumi M. 1998; The ultrastructure of yeast: cell wall structure and formation. Micron 29:207–233
    [Google Scholar]
  15. Pendland J. C., Boucias D. G. 1984; Use of labeled lectins to investigate cell-wall surfaces of the entomogenous hyphomycete Nomuraea rileyi . Mycopathologia 87:141–148
    [Google Scholar]
  16. Pendland J. C., Boucias D. G. 1986; Lectin binding characteristics of several entomogenous hyphomycetes – possible relationship to insect hemagglutinins. Mycologia 78:818–824
    [Google Scholar]
  17. Pendland J. C., Boucias D. G. 1992; Ultrastructural-localization of carbohydrate in cell-walls of the entomogenous hyphomycete Nomuraea rileyi . Can J Microbiol 38:377–386
    [Google Scholar]
  18. Pendland J. C., Boucias D. G. 1993; Variations in the ability of galactose and mannose-specific lectins to bind to cell-wall surfaces during growth of the insect pathogenic fungus Paecilomyces farinosus . Eur J Cell Biol 60:322–330
    [Google Scholar]
  19. Pendland J. C., Boucias D. G. 1996; Phagocytosis of lectin-opsonized fungal cells and endocytosis of the ligand by insect Spodoptera exigua granular hemocytes: an ultrastructural and immunocytochemical study. Cell Tissue Res 285:57–67
    [Google Scholar]
  20. Pendland J. C., Hung S. Y., Boucias D. G. 1993; Evasion of host defense by in vivo-produced protoplast-like cells of the insect mycopathogen Beauveria bassiana . J Bacteriol 175:5962–5969
    [Google Scholar]
  21. Sharon N. 2007; Lectins: carbohydrate-specific reagents and biological recognition molecules. J Biol Chem 282:2753–2764
    [Google Scholar]
  22. Sharon N., Lis H. 1993; Carbohydrates in cell recognition. Sci Am 268:82–89
    [Google Scholar]
  23. Smith S. N., Armstrong R. A., Barker M., Bird R. A., Chohan R., Hartell N. A., Whipps J. M. 1999; Determination of Coniothyrium minitans conidial and germling lectin avidity by flow cytometry and digital microscopy. Mycol Res 103:1533–1539
    [Google Scholar]
  24. Smith S. N., Armstrong R. A., Bird R. A., Chohan R., Hartell N. A., Poyner D. A. 2001; Characterization of FITC-conjugated lectin binding to Candida albicans . Mycologia 93:422–431
    [Google Scholar]
  25. Takeo K., Mine H., Nishimura K., Miyaji M. 1993; The existence of a dispensable fibrillar layer on the wall surface of mycelial but not yeast cells of Aureobasidium pullulans . FEMS Microbiol Lett 111:153–158
    [Google Scholar]
  26. Tartar A., Boucias D. G. 2004; A pilot-scale expressed sequence tag analysis of Beauveria bassiana gene expression reveals a tripeptidyl peptidase that is differentially expressed in vivo . Mycopathologia 158:201–209
    [Google Scholar]
  27. Teertstra W. R., van der Velden G. J., de Jong J. F., Kruijtzer J. A. W., Liskamp R. M. J., Kroon-Batenburg L. M. J., Muller W. H., Gebbink M. F. B. G., Wösten H. A. B. 2009; The filament-specific Rep1-1 repellent of the phytopathogen Ustilago maydis forms functional surface-active amyloid-like fibrils. J Biol Chem 284:9153–9159
    [Google Scholar]
  28. Thomas K. C., Khachatourians G. G., Ingledew W. M. 1987a; Production and properties of beauveria-bassiana conidia cultivated in submerged culture. Can J Microbiol 33:12–20
    [Google Scholar]
  29. Tronchin G., Bouchara J. P., Robert R. 1989; Dynamic changes of the cell-wall surface of Candida albicans associated with germination and adherence. Eur J Cell Biol 50:285–290
    [Google Scholar]
  30. Warwas M. L., Watson J. N., Bennet A. J., Moore M. M. 2007; Structure and role of sialic acids on the surface of Aspergillus fumigatus conidiospores. Glycobiology 17:401–410
    [Google Scholar]
  31. Wasylnka J. A., Simmer M. I., Moore M. M. 2001; Differences in sialic acid density in pathogenic and non-pathogenic Aspergillus species. Microbiology 147:869–877
    [Google Scholar]
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