title: Mammalian cell invasion and intracellular trafficking by Trypanosoma cruzi infective forms.
abstract: Trypanosoma cruzi, the etiological agent of Chagas disease, occurs as different strains or isolates that may be grouped in two major phylogenetic lineages: T. cruzi I, associated with the sylvatic cycle and T. cruzi II, linked to the human disease. In the mammalian host the parasite has to invade cells and many studies implicated the flagellated trypomastigotes in this process. Several parasite surface components and some of host cell receptors with which they interact have been identified. Our work focused on how amastigotes, usually found growing in the cytoplasm, can invade mammalian cells with infectivities comparable to that of trypomastigotes. We found differences in cellular responses induced by amastigotes and trypomastigotes regarding cytoskeletal components and actin-rich projections. Extracellularly generated amastigotes of T. cruzi I strains may display greater infectivity than metacyclic trypomastigotes towards cultured cell lines as well as target cells that have modified expression of different classes of cellular components. Cultured host cells harboring the bacterium Coxiella burnetii allowed us to gain new insights into the trafficking properties of the different infective forms of T. cruzi, disclosing unexpected requirements for the parasite to transit between the parasitophorous vacuole to its final destination in the host cell cytoplasm.
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, UNIFESP, Escola Paulista de Medicina, Rua Botucatu, 862, 6 andar, 04023-062 São Paulo, SP, Brazil. renato@ecb.epm.br
authors.forename: Renato A
authors.initials: RA
authors.lastname: Mortara
authors.forename: Walter K
authors.initials: WK
authors.lastname: Andreoli
authors.forename: Noemi N
authors.initials: NN
authors.lastname: Taniwaki
authors.forename: Adriana B
authors.initials: AB
authors.lastname: Fernandes
authors.forename: Claudio V da
authors.initials: CV
authors.lastname: Silva
authors.forename: Maria Cecília D C
authors.initials: MC
authors.lastname: Fernandes
authors.forename: Carolina
authors.initials: C
authors.lastname: L'Abbate
authors.forename: Solange da
authors.initials: Sd
authors.lastname: Silva
mesh_terms: D000818:Animals; D002478:Cells, Cultured / Q000469:parasitology; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000469:parasitology* / Q000648:ultrastructure; D006367:HeLa Cells / Q000469:parasitology; D006801:Humans; D046529:Microscopy, Electron, Transmission; D010802:Phylogeny; D014349:Trypanosoma cruzi / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D014709:Vero Cells / Q000469:parasitology