Neutrophil depletion exacerbates experimental Chagas' disease in BALB / c, but protects C57BL / 6 mice through modulating the Th1 / Th2 dichotomy in different directions

Chen, Lin; Watanabe, Tadashi; Watanabe, Hirotaka; Sendo, Fujiro

doi:10.1002/1521-4141(200101)31:1<265::aid-immu265>3.0.co;2-l

Cited by 95 publications

(40 citation statements)

References 40 publications

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“…Considering the fact that T. cruzi is responsible for complicated infections and that virulent strains of T. gondii express an isozyme (NTPase I) from a new family of E-type ATPases that is not expressed by avirulent T. gondii strains (Nakaar et al, 1998), and that the invasive form of E. histolytica has much higher Mgdependent ecto-ATPase activity than the noninvasive form (Barros et al 2000), one could also speculate that the presence of an Mg-dependent ecto-ATPase activity in T. cruzi might also reflect some form of evasion of the host defense mechanisms in the circulation. Taking into account that ATP can be released by different kinds of cells, such as neutrophils and endothelial cells (Fredholm 1997), and the role of these cells in the pathogenesis of Chagas' disease (Chen et al 2001;Petkova et al 2001), we suggested that Mg 2+ -dependent ecto-ATPase activity on T. cruzi could stimulate the adherence of parasites to the host cell and protect them from neutrophil attack through releasing adenosine to inhibit superoxide production. The results presented in Fig.…”

Section: Discussionmentioning

confidence: 99%

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

et al. 2004

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In this work, we describe the ability of living epimastigotes of Trypanosoma cruzi to hydrolyze extracellular ATP. In these intact parasites, there was a low level of ATP hydrolysis in the absence of any divalent metal (2.42 +/- 0.31 nmol Pi/h x 10(8) cells). ATP hydrolysis was stimulated by MgCl2, and the Mg-dependent ecto-ATPase activity was 27.15 +/- 2.91 nmol Pi/h x 10(8) cells. The addition of MgCl2 to the extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. This stimulatory activity was also observed when MgCl2 was replaced by MnCl2, but not by CaCl2 or SrCl2. The apparent Km for Mg-ATP2- was 0.61 mM, and free Mg2+ did not increase the ecto-ATPase activity. This ecto-ATPase activity was insensitive to the inhibitors of other ATPase and phosphatase activities. To confirm that this Mg-dependent ATPase was an ecto-ATPase, we used an impermeant inhibitor, DIDS (4, 4'.diisothiocyanostylbene 2'-2'-disulfonic acid) as well as suramin, an antagonist of P2 purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg2+-dependent ATPase activity in a dose-dependent manner. A comparison among the Mg2+-ecto-ATPase activities of the three forms of T. cruzi showed that the noninfective epimastigotes were less efficient at hydrolyzing ATP than the infective trypomastigote and amastigote stages.

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Section: Discussionmentioning

confidence: 99%

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

et al. 2004

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“…Taking account of the fact that ATP can be released by different kinds of cells, such as neutrophils and endothelial cells (Fredholm 1997), together with the role of these cells in the pathogenesis of Chagas¢ disease (Chen et al 2001;Petkova et al 2001), we suggest that Mg 2+ -dependent ecto-ATPase activity on T. cruzi could stimulate the adherence of parasites to host cells and protect them from neutrophil attack, by releasing adenosine to inhibit superoxide production.…”

Section: Discussionmentioning

confidence: 99%

Ecto-ATPase activity on the surface of Trypanosoma cruzi and its possible role in the parasite?host cell interaction

Bisaggio

Peres-Sampaio

Meyer‐Fernandes

et al. 2003

Parasitology Research

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This study describes the possible role of Mg(2+)-dependent ecto-ATPase activity on the Trypanosoma cruzi-host cell interaction. Mg(2+)-dependent ecto-ATPase activity is observed on the cell body and flagellar membranes of the parasite and is about 20 times greater in trypomastigotes, as compared with epimastigotes. Suramin (a competitive antagonist of P2 receptors) and the impermeant agent 4,4'-diisothiocyanostylbene 2',2'-disulfonic acid (DIDS), both inhibitors of ecto-ATPases, strongly inhibited ATPase activity and the adhesion and internalization of both evolutive forms by mouse resident macrophages. Suramin inhibited the growth of epimastigotes, suggesting a direct participation of ecto-ATPase activity in this process. To overcome the presence of suramin in the culture medium during the time of growth, Mg(2+) ecto-ATPase activity was enhanced 4-fold, as compared with control parasites. The over-expression in enzyme activity was followed by a dramatic increase in the adhesion of epimastigotes to resident macrophages above the level observed for non-treated parasites.

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“…[64,65] Trypanosoma cruzi Protection in C57BL/6 but aggravation of disease in BALB/c. [66] Yersinia enterocolitica…”

Section: Salmonella Typhimuriummentioning

confidence: 99%

Understanding the multiple functions of Gr-1+ cell subpopulations during microbial infection

et al. 2007

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The murine cell surface determinant Gr-1 is expressed at high level on neutrophils. Depletion of polymorphonuclear leukocytes with anti-Gr-1(+) monoclonal antibody results in increased susceptibility and dysregulated immunity to many microbial pathogens, a finding widely interpreted to indicate the importance of neutrophils during infection. Yet, in recent years it has become clear that additional cell types express the Gr-1 determinant, including dendritic cell and monocyte subpopulations. In this review, we evaluate current knowledge on the functional aspects of Gr-1(+) cell populations. We focus on infection with the opportunistic protozoan Toxoplasma gondii, a case where host survival depends on an intact Gr-1(+) cell population.

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Neutrophil depletion exacerbates experimental Chagas' disease in BALB / c, but protects C57BL / 6 mice through modulating the Th1 / Th2 dichotomy in different directions

Cited by 95 publications

References 40 publications

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

Ecto-ATPase activity on the surface of Trypanosoma cruzi and its possible role in the parasite?host cell interaction

Understanding the multiple functions of Gr-1+ cell subpopulations during microbial infection

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