Expression of the mammalian calcium signaling response to Trypanosoma cruzi in Xenopus laevis oocytes

Leite, M. Fátima; Moyer, M. Susan; Andrews, Norma W.

doi:10.1016/s0166-6851(97)00211-9

Cited by 25 publications

(15 citation statements)

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“…S2). Mechanistic studies of host cell invasion have shown that activation of G protein-coupled receptors induces an endocytic uptake of T. cruzi caused by IP3-mediated intracellular Ca 2+ release (Tardieux et al, 1994;Leite et al, 1998). To determine whether this is involved in the parasite uptake by TNF-alpha primed cells, we preincubated HEK293T and LLC-MK2 cells with 1 or 3 mM thapsigargin to deplete Ca 2+ stores, and then treated with TNF, and infected with T. cruzi.…”

Section: Tnf Treatment Increases the Invasion Of Human Epithelial Celmentioning

confidence: 99%

“…The majority of infected individuals pass through an asymptomatic chronic phase (indeterminate clinical form). The current view considers that factors related to both parasite and host genetic characteristics have a role in the pathogenesis of this infection (Macedo et al, 2004;Gutierrez et al, 2009).c mi_1636 1518.. 1529 The parasite entry into non-professional phagocytic cells depends on Ca 2+ signalling triggered by a G protein pathway (Tardieux et al, 1994;Leite et al, 1998). Adhesion of the parasite activates PLC (phospholipase C) and releases Ca 2+ from IP3 (Inositol Triphosphate)-sensitive intracellular stores (Rodriguez et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

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Tumour necrosis factor (TNF)-mediated NF-κB activation facilitates cellular invasion of non-professional phagocytic epithelial cell lines by Trypanosoma cruzi

Pinto

Sales

Camargos

et al. 2011

Cellular Microbiology

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SummaryAt the site of infection, pro-inflammatory cytokines locally produced by macrophages infected with Trypanosoma cruzi can activate surrounding nonprofessional phagocytes such as fibroblasts, epithelial and endothelial cells, which can be further invaded by the parasite. The effect of secreted soluble factors on the invasion of these cells remains, however, to be established. We show here that two epithelial cell lines become significantly susceptible to the infection by the Y strain of T. cruzi after tumour necrosis factor (TNF) treatment. The increase in the invasion was correlated with the increasing concentration of recombinant TNF added to cultures of HEK293T or LLC-MK2 cells. Supernatants taken from PMA-differentiated human monocytes infected with T. cruzi also increased the permissiveness of epithelial cells to subsequent infection with the parasite, which was inhibited by a TNF monoclonal antibody. Furthermore, the permissiveness induced by TNF was inhibited by TPCK, and led to significant decrease in the number of intracellular parasites, providing evidence that activation of NF-kB induced by TNF favours the invasion of the epithelial cell lines by T. cruzi through yet an unidentified mechanism. Our data indicate that soluble factors released from macrophages early in the infection favours T. cruzi invasion of non-professional phagocytic cells.

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Section: Tnf Treatment Increases the Invasion Of Human Epithelial Celmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Tumour necrosis factor (TNF)-mediated NF-κB activation facilitates cellular invasion of non-professional phagocytic epithelial cell lines by Trypanosoma cruzi

Pinto

Sales

Camargos

et al. 2011

Cellular Microbiology

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“…Infection also can occur in humans via exposure to contaminated blood during pregnancy or blood transfusion, in laboratory accidents or by ingestion of contaminated food (Moncayo & Ortiz Yanine 2006). After entry into the vertebrate host, the parasite can infect a wide variety of cells, including macrophages, smooth and striated muscle cells, fibroblasts, Schwann cells (Leite et al 1998). Ten to 30 years after infection with T. cruzi, some patients can develop severe cardiac and/or gastrointestinal involvement, both of which are major causes of morbidity and mortality in Chagas disease (Prata 2001).…”

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confidence: 99%

Differential tissue tropism of Trypanosoma cruzi strains: an in vitro study

Andrade¹,

Galvao

Meirelles

et al. 2010

Mem. Inst. Oswaldo Cruz

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We have previously demonstrated selection favoring the JG strain of Trypanosoma cruziin hearts of BALB/c mice that were chronically infected with an equal mixture of the monoclonal JG strain and a clone of the Colombian strain, Col1.7G2. To evaluate whether cell invasion efficiency drives this selection, we infected primary cultures of BALB/c cardiomyocytes using these same T. cruzi populations. Contrary to expectation, Col1.7G2 parasites invaded heart cell cultures in higher numbers than JG parasites; however, intracellular multiplication of JG parasites was more efficient than that of Col1.7G2 parasites. This phenomenon was only observed for cardiomyocytes and not for cultured Vero cells. Double infections (Col1.7G2 + JG) showed similar results. Even though invasion might influence tissue selection, our data strongly suggest that intracellular development is important to determine parasite tissue tropism

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“…In infective forms of T. cruzi, OpdB generates a calcium signaling factor which, via an interaction with a receptor at the mammalian cell surface (18), is responsible for the mobilization of Ca 2ϩ from intracellular calcium pools (4). This Ca 2ϩ signaling is a prerequisite for trypanosome invasion.…”

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confidence: 99%

Substrate Recognition Properties of Oligopeptidase B fromSalmonella entericaSerovar Typhimurium

2002

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Oligopeptidase B (OpdB) is a serine peptidase broadly distributed among unicellular eukaryotes, gramnegative bacteria, and spirochetes which has emerged as an important virulence factor and potential therapeutic target in infectious diseases. We report here the cloning and expression of the opdB homologue from Salmonella enterica serovar Typhimurium and demonstrate that it exhibits amidolytic activity exclusively against substrates with basic residues in P 1 . While similar to its eukaryotic homologues in terms of substrate specificity, Salmonella OpdB differs significantly in catalytic power and inhibition and activation properties. In addition to oligopeptide substrates, restricted proteolysis of histone proteins was observed, although no cleavage was seen at or near residues that had been posttranslationally modified or at defined secondary structures. This supports the idea that the catalytic site of OpdB may be accessible only to unstructured oligopeptides, similar to the closely related prolyl oligopeptidase (POP). Salmonella OpdB was employed as a model enzyme to define determinants of substrate specificity that distinguish OpdB from POP, which hydrolyzes substrates exclusively at proline residues. Using site-directed mutagenesis, nine acidic residues that are conserved in OpdBs but absent from POPs were converted to their corresponding residues in POP. In this manner, we identified a pair of glutamic acid residues, Glu 576 and Glu 578 , that define P 1 specificity and direct OpdB cleavage C terminal to basic residues. We have also identified a second pair of residues, Asp 460 and Asp 462 , that may be involved in defining P 2 specificity and thus direct preferential cleavage by OpdB after pairs of basic residues.The oligopeptidase B (OpdB; EC 3.4.21.83) subfamily of serine peptidases represents one of two branches of the prolyl oligopeptidase family of serine peptidases (the S9 family, in the nomenclature of Barrett and Rawlings [2]). The archetypical member of this family, prolyl oligopeptidase (POP; EC 3.4.21.26), exclusively hydrolyzes peptide bonds C terminal to proline residues in peptides (31). It has been implicated in the pathophysiology of depression (20) and has attracted pharmaceutical attention, since POP inhibitors have shown potential in the treatment of amnesia (39) and Alzheimer's disease (36). Prolyl oligopeptidase has also served as a model for structural studies of serine oligopeptidases. A 1.4-Å crystal structure analysis of POP recently revealed that an N-terminal regulatory domain, consisting of a seven-bladed ␤-propeller, regulates substrate access to the C-terminal catalytic domain (7) by a gating filter mechanism (8).In contrast to the POPs, the OpdB branch of the POP family has received much less attention. These enzymes demonstrate a trypsin-like substrate specificity, hydrolyzing peptide bonds on the C-terminal side of basic amino acid residues of lowmolecular-mass (Ͻ3 kDa) peptides (17,30,37,41). Of great importance for potential therapeutic applications, OpdB is only found i...

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Expression of the mammalian calcium signaling response to Trypanosoma cruzi in Xenopus laevis oocytes

Cited by 25 publications

References 38 publications

Tumour necrosis factor (TNF)-mediated NF-κB activation facilitates cellular invasion of non-professional phagocytic epithelial cell lines by Trypanosoma cruzi

Tumour necrosis factor (TNF)-mediated NF-κB activation facilitates cellular invasion of non-professional phagocytic epithelial cell lines by Trypanosoma cruzi

Differential tissue tropism of Trypanosoma cruzi strains: an in vitro study

Substrate Recognition Properties of Oligopeptidase B fromSalmonella entericaSerovar Typhimurium

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