Ontology highlight
ABSTRACT: Background
Plasmodium has a complex biology including the ability to interact with host signals modulating their function through cellular machinery. Tumor necrosis factor (TNF) elicits diverse cellular responses including effects in malarial pathology and increased infected erythrocyte cytoadherence. As TNF levels are raised during Plasmodium falciparum infection we have investigated whether it has an effect on the parasite asexual stage.Methods
Flow cytometry, spectrofluorimetric determinations, confocal microscopy and PCR real time quantifications were employed for characterizing TNF induced effects and membrane integrity verified by wheat germ agglutinin staining.Results
TNF is able to decrease intracellular parasitemia, involving calcium as a second messenger of the pathway. Parasites incubated for 48 h with TNF showed reduced erythrocyte invasion. Thus, TNF induced rises in intracellular calcium concentration, which were blocked by prior addition of the purinergic receptor agonists KN62 and A438079, or interfering with intra- or extracellular calcium release by thapsigargin or EGTA (ethylene glycol tetraacetic acid). Importantly, expression of PfPCNA1 which encodes the Plasmodium falciparum Proliferating-Cell Nuclear Antigen 1, decreased after P. falciparum treatment of TNF (tumor necrosis factor) or 6-Bnz cAMP (N(6)-benzoyladenosine-3',5'-cyclic monophosphate sodium salt).Conclusions
This is potentially interesting data showing the relevance of calcium in downregulating a gene involved in cellular proliferation, triggered by TNF.General significance
The data show that Plasmodium may subvert the immunological system and use TNF for the control of its proliferation within the vertebrate host.
SUBMITTER: Cruz LN
PROVIDER: S-EPMC4876768 | biostudies-literature | 2016 Jul
REPOSITORIES: biostudies-literature
Biochimica et biophysica acta 20160411 7
<h4>Background</h4>Plasmodium has a complex biology including the ability to interact with host signals modulating their function through cellular machinery. Tumor necrosis factor (TNF) elicits diverse cellular responses including effects in malarial pathology and increased infected erythrocyte cytoadherence. As TNF levels are raised during Plasmodium falciparum infection we have investigated whether it has an effect on the parasite asexual stage.<h4>Methods</h4>Flow cytometry, spectrofluorimetr ...[more]