Lysosome recruitment and fusion are early events required for trypanosome invasion of mammalian cells

Molecular Mechanisms of Membrane Trafficking. What do we Learn from Dictyostelium discoideum?

“…Elevation of the intracellular Ca 2 + concentration in rat kidney fibroblasts induces fusion of Iysosomes with the plasma membrane and exocytosis of lysosomal enzymes (Rodriguez et al 1997). The involvement of Ca 2 + transients in the invasion mechanism of the parasite Trypanosoma cruzi, which occurs by fusion of Iysosomes with the plasma membrane (Tardieux et al 1992), suggests that lysosome exocytosis is a process active in most cell types. In this context it is also relevant that specialised Ca 2 +-dependent secretory vesicles such as neutrophil azurophil granules, mast cell specific granules and cytotoxic lymphocyte lytic granules share characteristics with Iysosomes, maybe reflecting a common biogenesis (Griffiths 1996).…”

Dual Role of Signaling Pathways Leading to Ca2+and Cyclic AMP Elevation in Host Cell Invasion byTrypanosoma cruzi

“…Trypanosoma cruzi, the causative agent of Chagas' disease in humans, is a protozoan parasite capable of invading a large variety of cell types in its vertebrate host. Previous work from our laboratory revealed that invasion of many cell types by T. cruzi is independent of host actin polymerization and involves recruitment and fusion of host cell lysosomes at the site of parasite attachment (2,25,30,32).…”

Morphological comparison of axenic amastigogenesis of trypomastigotes and metacyclic forms of Trypanosoma cruzi

“…Flagellated trypomastigotes are ingested by vertebrate cells through a process referred to as parasite-directed endocytosis (Burleigh & Andrews 1995) with formation of a parasitecontaining endocytic vacuole which fuse with lysosomes from the host cell (Carvalho & De Sousa 1989, Tardieux et al 1992. Within 2 h after infection, the trypomastigotes can leave the acidic environment as a phagosome before the transformation into amastigotes is completed (Ley et al 1990) and enter the slightly alkaline environment of the cytoplasm, where they multiply as aflagellate amastigotes (Burleigh & Andrews 1995).…”