Dataset Information

Plasmodium falciparum gametocyte-infected erythrocytes do not adhere to human primary erythroblasts.

ABSTRACT: Plasmodium falciparum gametocytes, the sexual stages responsible for malaria parasite transmission, develop in the human bone marrow parenchyma in proximity to the erythroblastic islands. Yet, mechanisms underlying gametocytes interactions with these islands are unknown. Here, we have investigated whether gametocyte-infected erythrocytes (GIE) adhere to erythroid precursors, and whether a putative adhesion may be mediated by a mechanism similar to the adhesion of erythrocytes infected with P. falciparum asexual stages to uninfected erythrocytes. Cell-cell adhesion assays with human primary erythroblasts or erythroid cell lines revealed that immature GIE do not specifically adhere to erythroid precursors. To determine whether adhesion may be dependent on binding of STEVOR proteins to Glycophorin C on the surface of erythroid cells, we used clonal lines and transgenic parasites that overexpress specific STEVOR proteins known to bind to Glycophorin C in asexual stages. Our results indicate that GIE overexpressing STEVOR do not specifically adhere to erythroblasts, in agreement with our observation that the STEVOR adhesive domain is not exposed at the surface of GIE.

SUBMITTER: Neveu G

PROVIDER: S-EPMC6294825 | biostudies-other | 2018 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Plasmodium falciparum gametocyte-infected erythrocytes do not adhere to human primary erythroblasts.

Neveu Gaëlle G Dupuy Florian F Ladli Meriem M Barbieri Daniela D Naissant Bernina B Richard Cyrielle C Martins Rafael M RM Lopez-Rubio Jose-Juan JJ Bachmann Anna A Verdier Frédérique F Lavazec Catherine C

Scientific reports 20181214 1

Plasmodium falciparum gametocytes, the sexual stages responsible for malaria parasite transmission, develop in the human bone marrow parenchyma in proximity to the erythroblastic islands. Yet, mechanisms underlying gametocytes interactions with these islands are unknown. Here, we have investigated whether gametocyte-infected erythrocytes (GIE) adhere to erythroid precursors, and whether a putative adhesion may be mediated by a mechanism similar to the adhesion of erythrocytes infected with P. fa ...[more]

PMID: 30552367

Similar Datasets

Project description:BackgroundThe intra-erythrocytic development of the malaria parasite Plasmodium falciparum depends on the uptake of a number of essential nutrients from the host cell and blood plasma. It is widely recognized that the parasite imports low molecular weight solutes from the plasma and the consumption of these nutrients by P. falciparum has been extensively analysed. However, although it was already shown that the parasite also imports functional proteins from the vertebrate host, the internalization route through the different infected erythrocyte membranes has not yet been elucidated. In order to further understand the uptake mechanism, the study examined the trafficking of human plasminogen from the extracellular medium into P. falciparum-infected red blood cells.MethodsPlasmodium falciparum clone 3D7 was cultured in standard HEPES-buffered RPMI 1640 medium supplemented with 0.5% AlbuMAX. Exogenous human plasminogen was added to the P. falciparum culture and the uptake of this protein by the parasites was analysed by electron microscopy and Western blotting. Immunoprecipitation and mass spectrometry were performed to investigate possible protein interactions that may assist plasminogen import into infected erythrocytes. The effect of pharmacological inhibitors of different cellular physiological processes in plasminogen uptake was also tested.ResultsIt was observed that plasminogen was selectively internalized by P. falciparum-infected erythrocytes, with localization in plasma membrane erythrocyte and parasite's cytosol. The protein was not detected in parasitic food vacuole and haemoglobin-containing vesicles. Furthermore, in erythrocyte cytoplasm, plasminogen was associated with the parasite-derived membranous structures tubovesicular network (TVN) and Maurer's clefts. Several proteins were identified in immunoprecipitation assay and may be involved in the delivery of plasminogen across the P. falciparum multiple compartments.ConclusionThe findings here reported reveal new features regarding the acquisition of plasma proteins of the host by P. falciparum-infected erythrocytes, a mechanism that involves the exomembrane system, which is distinct from the haemoglobin uptake, clarifying a route that may be potentially targeted for inhibition studies.

Project description:In human erythrocytes (h-RBCs) various stimuli induce increases in [cAMP] that trigger ATP release. The resulting pattern of extracellular ATP accumulation (ATPe kinetics) depends on both ATP release and ATPe degradation by ectoATPase activity. In this study we evaluated ATPe kinetics from primary cultures of h-RBCs infected with P. falciparum at various stages of infection (ring, trophozoite and schizont stages). A "3V" mixture containing isoproterenol (?-adrenergic agonist), forskolin (adenylate kinase activator) and papaverine (phosphodiesterase inhibitor) was used to induce cAMP-dependent ATP release. ATPe kinetics of r-RBCs (ring-infected RBCs), t-RBCs (trophozoite-infected RBCs) and s-RBCs (schizont-infected RBCs) showed [ATPe] to peak acutely to a maximum value followed by a slower time dependent decrease. In all intraerythrocytic stages, values of ?ATP1 (difference between [ATPe] measured 1 min post-stimulus and basal [ATPe]) increased nonlinearly with parasitemia (from 2 to 12.5%). Under 3V exposure, t-RBCs at parasitemia 94% (t94-RBCs) showed 3.8-fold higher ?ATP1 values than in h-RBCs, indicative of upregulated ATP release. Pre-exposure to either 100 µM carbenoxolone, 100 nM mefloquine or 100 µM NPPB reduced ?ATP1 to 83-87% for h-RBCs and 63-74% for t94-RBCs. EctoATPase activity, assayed at both low nM concentrations (300-900 nM) and 500 µM exogenous ATPe concentrations increased approx. 400-fold in t94-RBCs, as compared to h-RBCs, while intracellular ATP concentrations of t94-RBCs were 65% that of h-RBCs. In t94-RBCs, production of nitric oxide (NO) was approx. 7-fold higher than in h-RBCs, and was partially inhibited by L-NAME pre-treatment. In media with L-NAME, ?ATP1 values were 2.7-times higher in h-RBCs and 4.2-times higher in t94-RBCs, than without L-NAME. Results suggest that P. falciparum infection of h-RBCs strongly activates ATP release via Pannexin 1 in these cells. Several processes partially counteracted ATPe accumulation: an upregulated ATPe degradation, an enhanced NO production, and a decreased intracellular ATP concentration.

Project description:BackgroundPrevious comparative proteomic analysis on Plasmodium falciparum isolates of different adhesion properties suggested that protein phosphorylation varies between isolates with different cytoadherence properties. But the extent and dynamic changes in phosphorylation have not been systematically studied. As a baseline for these future studies, this paper examined changes in the phosphoproteome of parasitized red blood cells (pRBC).MethodsMetabolic labelling with [35S] methionine on pRBC and 2D gel electrophoresis (2-DE) has previously been used to show the expression of parasite proteins and changes in protein iso-electric point (PI). 2-DE of different parasite strains was combined with immunoblotting using monoclonal antibodies specifically to phosphorylated serine/threonine and tyrosine, to obtain the phosphorylation profiles throughout the erythrocytic lifecycle. Affinity chromatography was used to purify/enrich phosphorylated proteins and these proteins from mature trophozoite stages which were identified using high-accuracy mass spectrometry and MASCOT search.Results2D-immunoblots showed that P. falciparum infection greatly increased phosphorylation of a set of proteins in pRBC, the dominant size classes for phosphorylated tyrosine proteins were 95, 60, 50 and 30 kDa and for phosphorylated serine/threonine were 120, 95, 60, 50, 43, 40 and 30 kDa. The most abundant molecules from 2D-gel mapping of phosphorylated proteins in ItG infected RBCs were identified by MALDI-TOF. A proteomic overview of phosphorylated proteins in pRBC was achieved by using complementary phosphorylated protein enrichment techniques combined with nano-flow LC/MS/MS analysis and MASCOT MS/MS ions search with phosphorylation as variable modifications. The definite phosphoproteins of pRBC are reported and discussed.ConclusionProtein phosphorylation is a major process in P. falciparum-parasitized erythrocytes. Preliminary screens identified 170 P. falciparum proteins and 77 human proteins as phosphorylated protein in pRBC, while only 48 human proteins were identified in the corresponding fractions from uninfected RBC. Refinement of the search to include significant ion scores indicating a specific phospho-peptide identified 21 P. falciparum proteins and 14 human proteins from pRBC, 13 host proteins were identified from normal RBC. The results achieved by complementary techniques consistently reflect a reliable proteomic overview of pRBC.

Dataset Information

Plasmodium falciparum gametocyte-infected erythrocytes do not adhere to human primary erythroblasts.

Publications

Plasmodium falciparum gametocyte-infected erythrocytes do not adhere to human primary erythroblasts.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets