Publications by authors named "Silene Macedo"

Host cell invasion is a critical step for infection by Trypanosoma cruzi, the agent of Chagas disease. In natural infection, T. cruzi metacyclic trypomastigote (MT) forms establish the first interaction with host cells.

View Article and Find Full Text PDF

The surface molecule gp82 of metacyclic trypomastigote (MT) forms of , the protozoan parasite that causes Chagas disease, mediates the host cell invasion, a process critical for the establishment of infection. Gp82 is known to bind to the target cell in a receptor-dependent manner, triggering Ca signal, actin cytoskeleton rearrangement and lysosome spreading. The host cell receptor for gp82 was recently identified as LAMP2, the major lysosome membrane-associated protein.

View Article and Find Full Text PDF

The involvement of β-adrenergic receptor (β-AR) in host cell invasion by Trypanosoma cruzi metacyclic trypomastigote (MT) is not known. We examined whether isoproterenol, an agonist of β-AR, or nonselective β-blocker propranolol affected MT internalization mediated the stage-specific surface molecule gp82. Treatment of HeLa cells with propranolol significantly inhibited MT invasion whereas isoproterenol had no effect.

View Article and Find Full Text PDF

Background: Outbreaks of acute Chagas disease by oral infection have been reported frequently over the last ten years, with higher incidence in northern South America, where Trypanosoma cruzi lineage TcI predominates, being responsible for the major cause of resurgent human disease, and a small percentage is identified as TcIV. Mechanisms of oral infection and host-cell invasion by these parasites are poorly understood. To address that question, we analyzed T.

View Article and Find Full Text PDF

Background: Diversity of T. cruzi strains is a central problem in Chagas disease research because of its correlation with the wide range of clinical manifestations and the biogeographical parasite distribution. The role played by parasite microdiversity in Chagas disease epidemiology is still debatable.

View Article and Find Full Text PDF

The molecular mechanisms of host cell invasion by T. cruzi metacyclic trypomastigotes (MT), the developmental forms that initiate infection in the mammalian host, are only partially understood. Here we aimed at further identifying the target cell components involved in signalling cascades leading to MT internalization, and demonstrate for the first time the participation of mammalian target of rapamycin (mTOR).

View Article and Find Full Text PDF

Oral infection by Trypanosoma cruzi has been the primary cause of recent outbreaks of acute Chagas' diseases. This route of infection may involve selective binding of the metacyclic trypomastigote surface molecule gp82 to gastric mucin as a first step towards invasion of the gastric mucosal epithelium and subsequent systemic infection. Here we addressed that question by performing in vitro and in vivo experiments.

View Article and Find Full Text PDF

Objective: The objective of this study was to investigate whether the infection of C57BL/6 mice by P. berghei ANKA, which causes severe malaria, was modulated by co-infection with Trypanosoma cruzi.

Methods: Groups of C57BL/6 mice were infected either with P.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionddqcmv1nfvj0hniak8j5glndjjrsff92): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once