Trypanosoma cruzi Infection Impairs the Endocytosis of Zymosan A by Cardiomyocytes.
OBJECTIVE
We have previously reported that mannose receptors participate and are regulated during Trypanosoma cruzi cardiomyocyte (CM) infection. Our present aim is to characterize the endocytosis of mannosylated ligands like zymosan A (Zy) in uninfected and T. cruzi-infected CM.


METHODS
CM infected or not by T. cruzi were incubated with Zy for different periods of time and their internalization was analyzed at light microscopy level. Fluorescent approaches were performed by treating Zy with concanavalin-A-TRITC and washing it exhaustively prior to incubation with CM. The cultures were further stained with phalloidin-FITC and DAPI for actin and DNA visualization, respectively.


RESULTS
CM internalized Zy particles in a time-dependent fashion. The ligand specificity was confirmed by the addition of mannan, which efficiently blocked the Zy endocytosis. Designed fluorescent approaches extended and confirmed the Zy internalization by striated cells. Infected cultures displayed impairment in Zy endocytosis, which seems to be directly related to host infection rates.


CONCLUSIONS
Altogether, our results show the ability of CM to ingest large particles such as the mannosylated ligand Zy. During their infection with T. cruzi, there is a loss in Zy internalization possibly due to the negative modulation of mannose receptors.
Soeiro
M N C
MN
Laboratório de Biologia Celular, Departamento de Ultra-estrutura e Biologia Celular, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, Brazil. soeiro@ioc.fiocruz.br
Mota
R A
RA
Batista
D G J
DG
Pereira
M C S
MC
Meirelles
M N L
MN
D000818:Animals; D002478:Cells, Cultured; D002598:Chagas Cardiomyopathy / Q000378:metabolism* / Q000469:parasitology; D004705:Endocytosis; D006801:Humans; D037181:Lectins, C-Type; D008351:Mannans / Q000494:pharmacology; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000469:parasitology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D014349:Trypanosoma cruzi; D015054:Zymosan / Q000378:metabolism
D037181:Lectins, C-Type; D008351:Mannans; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D015054:Zymosan