Virulence determinants of the human pathogenic fungus <scp><i>A</i></scp><i>spergillus fumigatus</i> protect against soil amoeba predation
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- Falk Hillmann
- Department of Molecular and Applied Microbiology Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute Jena Germany
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- Silvia Novohradská
- Department of Molecular and Applied Microbiology Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute Jena Germany
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- Derek J. Mattern
- Department of Molecular and Applied Microbiology Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute Jena Germany
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- Tilmann Forberger
- Department of Pharmaceutical Biology Institute of Pharmacy Friedrich Schiller University Jena Germany
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- Thorsten Heinekamp
- Department of Molecular and Applied Microbiology Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute Jena Germany
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- Martin Westermann
- Electron Microscopy Center Jena University Hospital Jena Germany
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- Thomas Winckler
- Department of Pharmaceutical Biology Institute of Pharmacy Friedrich Schiller University Jena Germany
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- Axel A. Brakhage
- Department of Molecular and Applied Microbiology Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute Jena Germany
説明
<jats:title>Summary</jats:title><jats:p>Filamentous fungi represent classical examples for environmentally acquired human pathogens whose major virulence mechanisms are likely to have emerged long before the appearance of innate immune systems. In natural habitats, amoeba predation could impose a major selection pressure towards the acquisition of virulence attributes. To test this hypothesis, we exploited the amoeba <jats:italic>Dictyostelium</jats:italic> discoideum to study its interaction with <jats:styled-content style="fixed-case"><jats:italic>A</jats:italic></jats:styled-content><jats:italic>spergillus fumigatus</jats:italic>, two abundant soil inhabitants for which we found co‐occurrence in various sites. Fungal conidia were efficiently taken up by <jats:styled-content style="fixed-case"><jats:italic>D</jats:italic></jats:styled-content><jats:italic>. discoideum</jats:italic>, but ingestion was higher when conidia were devoid of the green fungal spore pigment dihydroxynaphtalene melanin, in line with earlier results obtained for immune cells. Conidia were able to survive phagocytic processing, and intracellular germination was initiated only after several hours of co‐incubation which eventually led to a lethal disruption of the host cell. Besides phagocytic interactions, both amoeba and fungus secreted cross inhibitory factors which suppressed fungal growth or induced amoeba aggregation with subsequent cell lysis, respectively. On the fungal side, we identified gliotoxin as the major fungal factor killing <jats:styled-content style="fixed-case"><jats:italic>D</jats:italic></jats:styled-content><jats:italic>ictyostelium</jats:italic>, supporting the idea that major virulence attributes, such as escape from phagocytosis and the secretion of mycotoxins are beneficial to escape from environmental predators.</jats:p>
収録刊行物
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- Environmental Microbiology
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Environmental Microbiology 17 (8), 2858-2869, 2015-03-27
Wiley