title: Trypanosoma cruzi cell invasion and traffic: influence of Coxiella burnetii and pH in a comparative study between distinct infective forms.
abstract: Previous studies have shown that Coxiella burnetii, an intracellular bacterium that resides within acidified vacuoles with secondary lysosomal characteristics, is an effective modulator of the intracellular traffic of trypomastigote forms of Trypanosoma cruzi. In addition, vacuolar and cellular pH are related to fusion events that result in doubly infected phagosomes. T. cruzi, the etiological agent of Chagas' disease, occurs as different strains grouped in two major phylogenetic lineages: T. cruzi I, associated with the sylvatic cycle, and T. cruzi II, linked to the human disease. In this work we compared extracellular amastigotes (EA), metacyclic trypomastigotes (MT) and tissue culture derived trypomastigotes (TCT) belonging to T. cruzi I or T. cruzi II for their ability to invade and escape from their parasitophorous vacuole (PV), in Vero cells or Vero cells harboring the bacterium, C. burnetti. Distinct invasion patterns were observed between different infective stages and between infective forms of different strains. Studies on the transference kinetics revealed that pH modulates the intracellular traffic of each infective stage, but this influence is not exclusive for each phylogenetic group. Endosomal to lysosomal sequential labeling with EEA-1 and LAMP-1 of the PV formed during the entry of each infective form revealed that the phagosome maturation processes are distinct but not strain-dependent. Due to their low hemolysin and trans-sialidase activities, MTs are retained for longer periods in LAMP-1 positive vacuoles. Our results thus suggest that despite the contrasting invasion capabilities, parasites of distinct phylogenetic group behave in similar fashion once inside the host cell.
authors: Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Botucatu, 862, 6 andar, São Paulo, SP 04023-062, Brazil.
authors: Maria Cecília
authors: MC
authors: Fernandes
authors: Carolina
authors: C
authors: L'Abbate
authors: Walter
authors: W
authors: Kindro Andreoli
authors: Renato Arruda
authors: RA
authors: Mortara
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D016997:Coxiella burnetii / Q000502:physiology*; D011992:Endosomes / Q000737:chemistry / Q000469:parasitology; D006863:Hydrogen-Ion Concentration; D052118:Lysosomal-Associated Membrane Protein 1 / Q000032:analysis; D008247:Lysosomes / Q000737:chemistry / Q000469:parasitology; D008565:Membrane Proteins / Q000032:analysis; D008856:Microscopy, Fluorescence; D014349:Trypanosoma cruzi / Q000502:physiology*; D014617:Vacuoles / Q000469:parasitology*; D014709:Vero Cells; D033921:Vesicular Transport Proteins / Q000032:analysis
chemical_list: D052118:Lysosomal-Associated Membrane Protein 1; D008565:Membrane Proteins; D033921:Vesicular Transport Proteins; C093846:early endosome antigen 1