title: Lysosomal exocytosis: an important event during invasion of lamp deficient cells by extracellular amastigotes of Trypanosoma cruzi.
abstract: Trypanosoma cruzi is an obligate intracellular organism in vertebrate hosts. Lysosomes are involved in parasite invasion. LAMP-1 and LAMP-2 are the most abundant glycoproteins of the lysosomal membrane. This study is the first report on the invasion of T. cruzi extracellular amastigotes (EA) in single LAMP-1 or LAMP-2 knockouts, respectively, or in two independent LAMP-1/2 double-knockout cell lines. When compared to their respective wild type clones, the EA show higher infectivity in LAMP-2 knockouts, but no difference was seen in LAMP-1 knockout cells. Similarly, EA invasion rate was higher for one of the double knockout clones but not for the other. Higher lysosomal exocytosis correlated with a higher invasion rate and early lysosomal marker acquisition. These findings suggest that lysosomal exocytosis is important to EA cell invasion. Also, phagolysosome maturation in knockout cell lines differed from previous results revealing that EA enter cells by a mechanism other than receptor-mediated phagocytosis.
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Rua Botucatu 862, 6 Degrees Andar, São Paulo 04023-062 SP, Brazil.
authors.forename: Emanuelle Baldo
authors.initials: EB
authors.lastname: Gaspar
authors.forename: Renato Arruda
authors.initials: RA
authors.lastname: Mortara
authors.forename: Luciana O
authors.initials: LO
authors.lastname: Andrade
authors.forename: Claudio Vieira
authors.initials: CV
authors.lastname: da Silva
mesh_terms: D000818:Animals; D002460:Cell Line; D014355:Chagas Disease / Q000235:genetics / Q000469:parasitology / Q000503:physiopathology*; D005089:Exocytosis / Q000235:genetics; D006801:Humans; D052119:Lysosomal-Associated Membrane Protein 2 / Q000235:genetics / Q000502:physiology*; D051907:Lysosomal Membrane Proteins / Q000235:genetics / Q000502:physiology*; D008247:Lysosomes / Q000378:metabolism / Q000469:parasitology*; D051379:Mice; D018345:Mice, Knockout; D014349:Trypanosoma cruzi; D052118:Lysosomal-Associated Membrane Protein 1
chemical_list: D052119:Lysosomal-Associated Membrane Protein 2; D051907:Lysosomal Membrane Proteins; C052255:Lamp1 protein, mouse; D052118:Lysosomal-Associated Membrane Protein 1