Trypanosoma cruzi exposes phosphatidylserine as an evasion mechanism.
Chagas disease is caused by Trypanosoma cruzi and affects 18 million people in Central and South America. Here we analyzed the exposure of phosphatidylserine by the different forms of the parasite life cycle. Only the infective trypomastigotes, but not the epimastigotes or intracellular amastigotes, expose this phospholipid. This triggers a transforming growth factor beta signaling pathway, based on phosphorylated Smad 2 nuclear translocation, leading to iNOS disappearance in infected macrophages. This macrophage deactivation favors the survival of this intracellular parasite. Thus, phosphatidylserine exposure may be used by T. cruzi to evade innate immunity and be a common feature of obligate intracellular parasites that have to deal with activated macrophages.
Damatta
Renato A
RA
Laboratório de Biologia Celular e Tecidual, Universidade Federal do Rio de Janeiro, Rio de Janerio, RJ, Brazil. renato@uenf.br
Seabra
Sergio H
SH
Deolindo
Poliana
P
Arnholdt
Andréa C V
AC
Manhães
Lauro
L
Goldenberg
Samuel
S
de Souza
Wanderley
W
D021581:Active Transport, Cell Nucleus; D000818:Animals; D008264:Macrophages / Q000378:metabolism / Q000469:parasitology*; D051379:Mice; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010718:Phosphatidylserines / Q000378:metabolism*; D015398:Signal Transduction; D051899:Smad2 Protein / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000254:growth & development / Q000502:physiology*
D010718:Phosphatidylserines; D051899:Smad2 Protein; C497783:Smad2 protein, mouse; D016212:Transforming Growth Factor beta; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse