CONICET | Buscador de Institutos y Recursos Humanos

Trypanosoma cruzi is the causative agent of Chagas disease. This parasite requires the intracellular nichein order to proliferate and disseminate the infection. After invasion, T. cruzi resides temporarily in an acidic vacuolewhich is lysed by a not well-understood mechanism. Transmission electron microscopy was used to describe theprocess of T. cruzi escape from the parasitophorous vacuole over the time. Using HeLa (non-professional phagocyticcells) as host cell, we observed that recently internalized parasites reside in a membrane-bounded vacuole. A few hourslater, the first sign of vacuole disruption appeared as membrane discontinuities. This observation was followed by aprogressive vacuole swelling as evidenced by an electron-lucent halo between the parasite and the vacuole membrane.Apparently, the vacuole membrane remnants reorganized as small vesicles that eventually disappeared from the vicinityof the parasites. Finally, parasites reach the host cell cytosol where replication takes place. The thorough ultrastructuraldescription of this process set the base for a comprehensive understanding of the parasite-host cell interaction and, thusopen the possibility of new therapeutic intervention strategies.