en
Preprint
English

Conidial melanin of the human pathogenic fungus Aspergillus fumigatus disrupts cell autonomous defenses in amoebae

Publication date2019
Abstract

The human pathogenic fungus is a ubiquitous saprophyte that causes fatal infections in immunocompromised individuals. Following inhalation, conidia are ingested by innate immune cells and can arrest phagolysosome maturation. How such general virulence traits could have been selected for in natural environments is unknown. Here, we used the model amoeba to follow the antagonistic interaction of conidia with environmental phagocytes in real time. We found that conidia covered with the green pigment 1,8-dihydroxynaphthalene-(DHN)-melanin were internalized at far lower rates when compared to those lacking the pigment, despite high rates of initial attachment. Immediately after uptake of the fungal conidia, nascent phagosomes were formed through sequential membrane fusion and fission events. Using single-cell assays supported by a computational model integrating the differential dynamics of internalization and phagolysosome maturation, we could show that acidification of phagolysosomes was transient and was followed by neutralization and, finally, exocytosis of the conidium. For unpigmented conidia, the cycle was completed in less than 1 h, while the process was delayed for conidia covered with DHN-melanin. At later stages of infection, damage to infected phagocytes triggered the ESCRT membrane repair machinery, whose recruitment was also attenuated by DHN-melanin, favoring prolonged persistence and the establishment of an intracellular germination niche in this environmental phagocyte. Increased exposure of DHN-melanin on the conidial surface also improved fungal survival when confronted with the fungivorous predator , demonstrating its universal antiphagocytic properties.

NoteSoumis dans : BioRxiv
Research group
Citation (ISO format)
FERLING, Iuliia et al. Conidial melanin of the human pathogenic fungus Aspergillus fumigatus disrupts cell autonomous defenses in amoebae. 2019. doi: 10.1101/730879
Main files (1)
Preprint
accessLevelPublic
Identifiers
229views
64downloads

Technical informations

Creation06/18/2020 12:26:00 PM
First validation06/18/2020 12:26:00 PM
Update time03/15/2023 10:10:33 PM
Status update03/15/2023 10:10:33 PM
Last indexation01/17/2024 10:12:03 AM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack