title: Molecular and cellular mechanisms involved in the Trypanosoma cruzi/host cell interplay.
abstract: The protozoan parasite Trypanosoma cruzi has a complex biological cycle that involves vertebrate and invertebrate hosts. In mammals, the infective trypomastigote form of this parasite can invade several cell types by exploiting phagocytic-like or nonphagocytic mechanisms depending on the class of cell involved. Morphological studies showed that when trypomastigotes contact macrophages, they induce the formation of plasma membrane protrusions that differ from the canonical phagocytosis that occurs in the case of noninfective epimastigotes. In contrast, when trypomastigotes infect epithelial or muscle cells, the cell surface is minimally modified, suggesting the induction of a different class of process. Lysosomal-dependent or -independent T. cruzi invasion of host cells are two different models that describe the molecular and cellular events activated during parasite entry into nonphagocytic cells. In this context, we have previously shown that induction of autophagy in host cells before infection favors T. cruzi invasion. Furthermore, we demonstrate that autophagosomes and the autophagosomal protein LC3 are recruited to the T. cruzi entry sites and that the newly formed T. cruzi parasitophorous vacuole has characteristics of an autophagolysosome. This review summarizes the current knowledge of the molecular and cellular mechanisms of T. cruzi invasion in nonphagocytic cells. Based on our findings, we propose a new model in which T. cruzi takes advantage of the upregulation of autophagy during starvation to increase its successful colonization of host cells.
authors.affiliation: Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina. promano@fcm.uncu.edu.ar
authors.forename: Patricia Silvia
authors.initials: PS
authors.lastname: Romano
authors.forename: Juan Agustín
authors.initials: JA
authors.lastname: Cueto
authors.forename: Ana Florencia
authors.initials: AF
authors.lastname: Casassa
authors.forename: María Cristina
authors.initials: MC
authors.lastname: Vanrell
authors.forename: Roberta A
authors.initials: RA
authors.lastname: Gottlieb
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Colombo
mesh_terms: D000818:Animals; D001343:Autophagy; D015815:Cell Adhesion Molecules / Q000378:metabolism / Q000502:physiology; D014355:Chagas Disease / Q000469:parasitology*; D006790:Host-Parasite Interactions; D006801:Humans; D008247:Lysosomes / Q000469:parasitology; D008954:Models, Biological; D010587:Phagocytosis; D015800:Protozoan Proteins / Q000378:metabolism / Q000502:physiology; D014349:Trypanosoma cruzi / Q000502:physiology*
chemical_list: D015815:Cell Adhesion Molecules; D015800:Protozoan Proteins; C013065:cell aggregation factors