Influence of Ecto-Nucleoside Triphosphate Diphosphohydrolase Activity on Trypanosoma cruzi Infectivity and Virulence

Abstract

BackgroundThe protozoan Trypanosoma cruzi is the causative agent of Chagas disease. There are no vaccines or effective treatment, especially in the chronic phase when most patients are diagnosed. There is a clear necessity to develop new drugs and strategies for the control and treatment of Chagas disease. Recent papers have suggested the ecto-nucleotidases (from CD39 family) from pathogenic agents as important virulence factors. In this study we evaluated the influence of Ecto-Nucleoside-Triphosphate-Diphosphohydrolase (Ecto-NTPDase) activity on infectivity and virulence of T. cruzi using both in vivo and in vitro models.Methodology/Principal FindingsWe followed Ecto-NTPDase activities of Y strain infective forms (trypomastigotes) obtained during sequential sub-cultivation in mammalian cells. ATPase/ADPase activity ratios of cell-derived trypomastigotes decreased 3- to 6-fold and infectivity was substantially reduced during sequential sub-cultivation. Surprisingly, at third to fourth passages most of the cell-derived trypomastigotes could not penetrate mammalian cells and had differentiated into amastigote-like parasites that exhibited 3- to 4-fold lower levels of Ecto-NTPDase activities. To evidence the participation of T. cruzi Ecto-NTPDase1 in the infective process, we evaluated the effect of known Ecto-ATPDase inhibitors (ARL 67156, Gadolinium and Suramin), or anti-NTPDase-1 polyclonal antiserum on ATPase and ADPase hydrolytic activities in recombinant T. cruzi NTPDase-1 and in live trypomastigotes. All tests showed a partial inhibition of Ecto-ATPDase activities and a marked inhibition of trypomastigotes infectivity. Mice infections with Ecto-NTPDase-inhibited trypomastigotes produced lower levels of parasitemia and higher host survival than with non-inhibited control parasites.Conclusions/SignificanceOur results suggest that Ecto-ATPDases act as facilitators of infection and virulence in vitro and in vivo and emerge as target candidates in chemotherapy of Chagas disease.

CD73 Inhibition Shifts Cardiac Macrophage Polarization toward a Microbicidal Phenotype and Ameliorates the Outcome of Experimental Chagas Cardiomyopathy

“…In this sense, the ecto-nucleoside-triphosphate-diphosphohydrolase, homolog to CD39 family enzymes, is localized on the external surface of all biological stages of T. cruzi, and it has been proposed as new chemotherapy target to block the infection (47). Moreover, the infective form (trypomastigote) presents the highest ATP hydrolysis rate, and its enzymatic activity increases in vitro cell infection and parasitemia in a murine model of Chagas disease (47). However, there are no reports about the effect of APCP in parasite ectonucleotidases.…”

The Leishmania-Macrophage Interactions: Role of E-NTPDases and Purinergic Signaling

“…The GP63, a zinc-metalloprotease named glycoprotein 63 (GP63), is another critical virulence factor that has been fully explored [34][35][36][37][38] . However, the E-NTPDases (ecto-nucleoside triphosphate diphosphohydrolases), while less-extensively studied, have been demonstrated and believed to be important infectivity and virulence factors [39][40][41][42][43][44][45][46][47][48] .…”

Implication of purinergic signaling pathways in clinical management of Chagas' disease

“…All those mediators are highly toxic to T. cruzi 18 . It has been described that Tc-ENTPDase-1 might play a modulatory role in response to these toxic mediators and in consequence affect purine recovery pathways, which are necessary for nutrition and to maintain parasite viability; beyond this, they can be involved in inflammatory processes, modulation of the host immune system and consequently increase the virulence mechanisms of T. cruzi 17,19,20 . A virulence key mechanism related to Tc-ENTPDase-1 presents a relation with enzyme capacity that interferes with extracellular ATP signals and interrupts purinergic signalling, limiting mechanisms of host defences.…”

“…Trypanocidal drugs that are able to influence the biochemical activity of purinergic receptors, acting like competitive antagonists of P2X and P2Y receptors, may be promising in the clinical management of Chagas disease 24 . It has been shown that there is a strong correlation of ecto-ATPase activity inhibition with reduced capacity of adhesion and internalisation of T. cruzi in the host cell 17,20 . An important ecto-ATPase inhibitor, capable of interfering with purinergic receptors and consequently in the biology of T. cruzi, is suramin, a polysulphonated naphthylurea compound, derivative of urea, that functions as a competitive antagonist of P2 receptors, used for the prophylactic treatment of African tripassonomiase 25 .…”

“…Although these authors pointed the involvement of suramin on biological mechanisms related to Tc-NTPDase inhibition, due to binding to P2 receptors, this activity has been demonstrated only in vitro. Relative ineffectiveness of suramin has been demonstrated in studies in vivo and there are urgent necessities of controlled preclinical and clinical studies to define the molecular mechanisms involved in the modulation of parasite biology 19,20 . Thus, we considered suramin and purinergic signalling inhibition as a promising target in the clinical management of Chagas disease.…”