In VitroInteraction of Alveolar Macrophages andAspergillus Fumigatus

Reaction of Human Alveolar Macrophages to Exposure toAspergillus fumigatusand Inert Particles

“…The high pH (ജ6.5) might be explained by passages between the phagolysosomes containing the conidia and the cell surface. The existence of such channels have been shown by electron microscopic investigations for phagolysosomes with conidia of A. fumigatus and A. candidus (Nessa et al, 1997). However, it was not technically possible to correlate such passages with phagolysosomes with high pH.…”

“…We have recently studied the reactions of rat AM on exposure to conidia of Aspergillus species (Nessa et al, 1997). Compared with inert particles the conidia were phagocytized at a higher rate, mainly because of a higher ingestion rate.…”

Aspergillus fumigatus conidia survive and germinate in acidic organelles of A549 epithelial cells

“…After 12 hours postinfection, there was a 10-fold difference in viability between the conidia in J774 and A549 cells; 99% of the conidia added to J774 cells had been washed off or killed, whereas significant amounts of viable conidia remained in the A549 cells after 24 hours (3% of the initial inoculum). The oxidative metabolism of alveolar macrophages during phagocytosis of A. fumigatus conidia has been well documented (Gil-Lamaignere et al, 2001;Nessa et al, 1997). In both cell lines, conidia resided in acidic organelles containing lysosomal proteins, therefore, the difference in killing rates between the two cell lines was most likely due to the respiratory burst present in J774 cells.…”

“…Previous work by our laboratory and others has determined that A. fumigatus conidia are internalized by lung cells (DeHart et al, 1997;Paris et al, 1997;Wasylnka and Moore, 2002) endothelial cells (Paris et al, 1997;Wasylnka and Moore, 2002) and macrophages (Nessa et al, 1997;Wasylnka and Moore, 2002) in vitro. We have previously demonstrated that 100% of conidia internalized by A549 lung epithelial cells survive for at least 3 1/2 hours following uptake, whereas 70% of conidia internalized by J774 murine macrophages are killed within 6 hours.…”

Ability to grow on lipids accounts for the fully virulent phenotype in neutropenic mice of Aspergillus fumigatus null mutants in the key glyoxylate cycle enzymes

“…fumigatus conidia (De Hart et al, 1997;Ibrahim-Granet et al, 2003;Latgé, 2001;Nessa et al, 1997;Paris et al, 1997;Wasylnka and Moore, 2002). Interestingly, in vitro studies have shown important differences in the outcome of the phagocytosed conidia depending on whether the infected cell is the alveolar macrophage or the pneumocyte (Ibrahim-Granet et al, 2003;Wasylnka and Moore, 2003).…”