Intracellular and extracellular growth ofAspergillus fumigatus
| Autor: | Julie A. Wasylnka, A. H. T. Hissen, Adrian Wan, Margo M. Moore |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Hypha
Iron media_common.quotation_subject Cell Line Microbiology Aspergillus fumigatus Mice Phagosomes Extracellular Animals Aspergillosis Humans Macrophage skin and connective tissue diseases Internalization Lung media_common A549 cell biology Macrophages fungi General Medicine respiratory system biology.organism_classification Infectious Diseases Cell culture Intracellular |
| Zdroj: | Medical Mycology. 43:27-30 |
| ISSN: | 1460-2709 1369-3786 |
| DOI: | 10.1080/13693780400029247 |
| Popis: | Aspergillus fumigatus is a filamentous fungus that can cause a life-threatening systemic mycosis in immunocompromised patients. We have studied the growth of A. fumigatus inside cultured cells, and the extracellular growth requirements (in serum). We measured the uptake of bound conidia by the cultured human type II pneumocyte cell line (A549) and a mouse macrophage cell line (J774). The extent of internalization was determined using a nystatin protection assay and by confocal microscopy. Both assays showed that A549 cells internalized 30% of bound conidia after three hours. In contrast, the value for J774 cells was 90%. In both J774 and A549 cells, conidia entered the endosomal pathway and ultimately co-localized with lysosomal markers. Lysosomes containing conidia were acidified. Internalized conidia germinated, and after 24-36 h of incubation with A549 cells, the hyphal tips of some intracellular germlings became exposed to the extracellular space. The importance of iron acquisition to extracellular growth was assessed by creating a strain of A. fumigatus in which the gene encoding the first step of hydroxamate siderophore biosynthesis, ornithine N5-oxygenase (AfusidA), was inactivated by gene replacement. Mutant strains were avirulent in a mouse model of invasive aspergillosis indicating that siderophore biosynthesis is a virulence factor in A. fumigatus. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|