Lysosomal exocytosis: an important event during invasion of lamp deficient cells by extracellular amastigotes of Trypanosoma cruzi.
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.
Gaspar
Emanuelle Baldo
EB
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Rua Botucatu 862, 6 Degrees Andar, São Paulo 04023-062 SP, Brazil.
Mortara
Renato Arruda
RA
Andrade
Luciana O
LO
da Silva
Claudio Vieira
CV
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
D052119:Lysosomal-Associated Membrane Protein 2; D051907:Lysosomal Membrane Proteins; C052255:Lamp1 protein, mouse; D052118:Lysosomal-Associated Membrane Protein 1