Effects of anionic inhibitors of phagosome-lysosome fusion in cultured macrophages when the ingested organism is Mycobacterium lepraemurium.

Inhibition of phagosome-lysosome fusion in macrophages by certain mycobacteria can be explained by inhibition of lysosomal movements observed after phagocytosis

We have investigated the mechanism of the inhibition of phagosome-lysosome (P-L) fusion in macrophages known to occur after infection by Mycobacterium tuberculosis and by the mouse pathogen Mycobacterium microti. We have used an M. microti infection and have studied, first, the saltatory movements of periphagosomal secondary lysosomes by means of visual phase-contrast microscopy (a similar use ...

Membrane vesicles shed by Legionella pneumophila inhibit fusion of phagosomes with lysosomes.

When cultured in broth to the transmissive phase, Legionella pneumophila infects macrophages by inhibiting phagosome maturation, whereas replicative-phase cells are transported to the lysosomes. Here we report that the ability of L. pneumophila to inhibit phagosome-lysosome fusion correlated with developmentally regulated modifications of the pathogen's surface, as judged by its lipopolysacchar...

Mannose receptor-dependent delay in phagosome maturation by Mycobacterium avium glycopeptidolipids.

The ability of pathogenic mycobacteria to block phagosome-lysosome fusion is critical for its pathogenesis. The molecules expressed by mycobacteria that inhibit phagosome maturation and the mechanism of this inhibition have been extensively studied. Recent work has indicated that mannosylated lipoarabinomannan (ManLAM) isolated from Mycobacterium tuberculosis can function to delay phagosome-lys...

Prevention of phagosome-lysosome fusion in cultured macrophages by sulfatides of Mycobacterium tuberculosis.

Intracellular parasites (e.g., Mycobacterium tuberculosis, Toxoplasma gondii, and some Chlamydiae) may promote their survival within the host by acting from within phagosomes to prevent phagolysosome formation, thus avoiding exposure to the lysosomal hydrolases. The present studies demonstrate that when sulfatides of M. tuberculosis (anionic trehalose glycolipids largely responsible for the neu...

Macrophages and Intracellular Survival in Human Inhibition of Phagosome-Lysosome Fusion Signal Transduction: Contribution to Exhibit Altered Calmodulin-Dependent Phagosomes Mycobacterium tuberculosis