scholarly journals Erythrocyte CD55 mediates the internalization of Plasmodium falciparum parasites

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Bikash Shakya ◽  
Saurabh D Patel ◽  
Yoshihiko Tani ◽  
Elizabeth S Egan
Keyword(s):  
Plasmodium Falciparum ◽  
Live Cell Imaging ◽  
Malaria Parasite ◽  
Cell Imaging ◽  
Erythrocyte Deformability ◽  
Host Factors ◽  
Unique Role ◽  
Forward Genetic Screen ◽  
Step Process ◽  
Complex Process

Invasion of human erythrocytes by the malaria parasite Plasmodium falciparum is a multi-step process. Previously, a forward genetic screen for P. falciparum host factors identified erythrocyte CD55 as essential for invasion, but its specific role and how it interfaces with the other factors that mediate this complex process are unknown. Using CRISPR-Cas9 editing, antibody-based inhibition, and live cell imaging, here we show that CD55 is specifically required for parasite internalization. Pre-invasion kinetics, erythrocyte deformability, and echinocytosis were not influenced by CD55, but entry was inhibited when CD55 was blocked or absent. Visualization of parasites attached to CD55-null erythrocytes point to a role for CD55 in stability and/or progression of the moving junction. Our findings demonstrate that CD55 acts after discharge of the parasite's rhoptry organelles, and plays a unique role relative to all other invasion receptors. As the requirement for CD55 is strain-transcendent, these results suggest that CD55 or its interacting partners may hold potential as therapeutic targets for malaria.

scholarly journals Erythrocyte CD55 facilitates the internalization of Plasmodium falciparum parasites

2020 ◽  
Author(s):  
Bikash Shakya ◽  
Saurabh D. Patel ◽  
Yoshihiko Tani ◽  
Elizabeth S. Egan
Keyword(s):  
Plasmodium Falciparum ◽  
Live Cell Imaging ◽  
Malaria Parasite ◽  
Cell Imaging ◽  
Erythrocyte Deformability ◽  
Host Factors ◽  
Unique Role ◽  
Forward Genetic Screen ◽  
Step Process ◽  
Complex Process

AbstractInvasion of human erythrocytes by the malaria parasite Plasmodium falciparum is a multi-step process. Previously, a forward genetic screen for P. falciparum host factors identified erythrocyte CD55 as essential for invasion, but its specific role and how it interfaces with the other factors that mediate this complex process are unknown. Using CRISPR-Cas9 editing, antibody-based inhibition, and live cell imaging, here we show that CD55 is specifically required for parasite internalization. Pre-invasion kinetics, erythrocyte deformability, and echinocytosis were not influenced by CD55, but entry was inhibited when CD55 was blocked or absent. Visualization of parasites attached to CD55-null erythrocytes point to a role for CD55 in progression of the moving junction. Our findings demonstrate that CD55 acts after discharge of the parasite’s rhoptry organelles, and plays a unique role relative to all other invasion receptors. As the requirement for CD55 is strain-transcendent, these results suggest that CD55 or its interacting partners may hold potential as therapeutic targets for malaria.

scholarly journals A Photoalkylative Fluorogenic Probe of Guttiferone A for Live Cell Imaging and Proteome Labeling in Plasmodium falciparum

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5139
Author(s):  
Romain Duval ◽  
Kevin Cottet ◽  
Magali Blaud ◽  
Anaïs Merckx ◽  
Sandrine Houzé ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Natural Product ◽  
Drug Targets ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Molecular Probe ◽  
Positive Functional ◽  
Fluorogenic Probe ◽  
Symphonia Globulifera

Guttiferone A (GA) 1, a polycyclic polyprenylated acylphloroglucinol (PPAP) isolated from the plant Symphonia globulifera (Clusiaceae), constitutes a novel hit in antimalarial drug discovery. PPAPs do not possess identified biochemical targets in malarial parasites up to now. Towards this aim, we designed and evaluated a natural product-derived photoactivatable probe AZC-GA 5, embedding a photoalkylative fluorogenic motif of the 7-azidocoumarin (AZC) type, devoted to studying the affinity proteins interacting with GA in Plasmodium falciparum. Probe 5 manifested a number of positive functional and biological features, such as (i) inhibitory activity in vitro against P. falciparum blood-stages that was superimposable to that of GA 1, dose–response photoalkylative fluorogenic properties (ii) in model conditions using bovine serum albumin (BSA) as an affinity protein surrogate, (iii) in live P. falciparum-infected erythrocytes, and (iv) in fresh P. falciparum cell lysate. Fluorogenic signals by photoactivated AZC-GA 5 in biological settings were markedly abolished in the presence of excess GA 1 as a competitor, indicating significant pharmacological specificity of the designed molecular probe relative to the native PPAP. These results open the way to identify the detected plasmodial proteins as putative drug targets for the natural product 1 by means of proteomic analysis.

scholarly journals Characterization of a Conserved Rhoptry-Associated Leucine Zipper-Like Protein in the Malaria Parasite Plasmodium falciparum

2008 ◽  
Vol 76 (3) ◽  
pp. 879-887 ◽  
Author(s):  
Silvia Haase ◽  
Ana Cabrera ◽  
Christine Langer ◽  
Moritz Treeck ◽  
Nicole Struck ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Leucine Zipper ◽  
Gene Knockout ◽  
Structural Features ◽  
Specific Protein ◽  
Complex Process ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
High Degree

ABSTRACT One of the key processes in the pathobiology of the malaria parasite is the invasion and subsequent modification of the human erythrocyte. In this complex process, an unknown number of parasite proteins are involved, some of which are leading vaccine candidates. The majority of the proteins that play pivotal roles in invasion are either stored in the apical secretory organelles or located on the surface of the merozoite, the invasive stage of the parasite. Using transcriptional and structural features of these known proteins, we performed a genomewide search that identified 49 hypothetical proteins with a high probability of being located on the surface of the merozoite or in the secretory organelles. Of these candidates, we characterized a novel leucine zipper-like protein in Plasmodium falciparum that is conserved in Plasmodium spp. This protein is expressed in late blood stages and localizes to the rhoptries of the parasite. We demonstrate that this Plasmodium sp.-specific protein has a high degree of conservation within field isolates and that it is refractory to gene knockout attempts and thus might play an important role in invasion.

scholarly journals Genotypes and phenotypes of resistance in Ecuadorian Plasmodium falciparum

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Gabriela Valenzuela ◽  
L. Enrique Castro ◽  
Julio Valencia-Zamora ◽  
Claudia A. Vera-Arias ◽  
Petra Rohrbach ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Chloroquine Resistance ◽  
In Vitro Assays ◽  
Wild Type ◽  
The Status ◽  
Transport Assay ◽  
Resistance Markers

Abstract Background Malaria continues to be endemic in the coast and Amazon regions of Ecuador. Clarifying current Plasmodium falciparum resistance in the country will support malaria elimination efforts. In this study, Ecuadorian P. falciparum parasites were analysed to determine their drug resistance genotypes and phenotypes. Methods Molecular analyses were performed to search for mutations in known resistance markers (Pfcrt, Pfdhfr, Pfdhps, Pfmdr1, k13). Pfmdr1 copy number was determined by qPCR. PFMDR1 transporter activity was characterized in live parasites using live cell imaging in combination with the Fluo-4 transport assay. Chloroquine, quinine, lumefantrine, mefloquine, dihydroartemisinin, and artemether sensitivities were measured by in vitro assays. Results The majority of samples from this study presented the CVMNT genotype for Pfcrt (72–26), NEDF SDFD mutations in Pfmdr1 and wild type genotypes for Pfdhfr, Pfdhps and k13. The Ecuadorian P. falciparum strain ESM-2013 showed in vitro resistance to chloroquine, but sensitivity to quinine, lumefantrine, mefloquine, dihydroartemisinin and artemether. In addition, transport of the fluorochrome Fluo-4 from the cytosol into the digestive vacuole (DV) of the ESM-2013 strain was minimally detected in the DV. All analysed samples revealed one copy of Pfmdr1. Conclusion This study indicates that Ecuadorian parasites presented the genotype and phenotype for chloroquine resistance and were found to be sensitive to SP, artemether-lumefantrine, quinine, mefloquine, and dihydroartemisinin. The results suggest that the current malaria treatment employed in the country remains effective. This study clarifies the status of anti-malarial resistance in Ecuador and informs the P. falciparum elimination campaigns in the country.

scholarly journals Apicoplast and Mitochondrion in Gametocytogenesis of Plasmodium falciparum

2008 ◽  
Vol 8 (1) ◽  
pp. 128-132 ◽  
Author(s):  
Noriko Okamoto ◽  
Timothy P. Spurck ◽  
Christopher D. Goodman ◽  
Geoffrey I. McFadden
Keyword(s):  
Plasmodium Falciparum ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Maternal Inheritance ◽  
Live Cell ◽  
Close Connection ◽  
Morphological Development ◽  
Malaria Parasites ◽  
Human Malaria ◽  
Male Gametes

ABSTRACT Live cell imaging of human malaria parasites Plasmodium falciparum during gametocytogenesis revealed that the apicoplast does not grow, whereas the mitochondrion undergoes remarkable morphological development. A close connection of the two organelles is consistently maintained. The apicoplast and mitochondrion are not components of the male gametes, suggesting maternal inheritance.

scholarly journals Plasmodium falciparum STEVOR phosphorylation regulates host erythrocyte deformability enabling malaria parasite transmission

Blood ◽  
2016 ◽  
Vol 127 (24) ◽  
pp. e42-e53 ◽  
Author(s):  
Bernina Naissant ◽  
Florian Dupuy ◽  
Yoann Duffier ◽  
Audrey Lorthiois ◽  
Julien Duez ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Infected Erythrocyte ◽  
Cytoplasmic Domain ◽  
Erythrocyte Deformability ◽  
Parasite Transmission ◽  
Key Points

Key Points P falciparum STEVORs interact with the erythrocyte cytoskeletal ankyrin complex. Infected erythrocyte deformability is regulated by PKA-mediated phosphorylation of STEVOR cytoplasmic domain.

Whole cell imaging reveals novel modular features of the exomembrane system of the malaria parasite, Plasmodium falciparum

2010 ◽  
Vol 40 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Eric Hanssen ◽  
Peter Carlton ◽  
Samantha Deed ◽  
Nectarios Klonis ◽  
John Sedat ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Cell Imaging ◽  
Whole Cell ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum

scholarly journals Kinesin-8B controls basal body function and flagellum formation and is key to malaria parasite transmission

2019 ◽  
Author(s):  
Mohammad Zeeshan ◽  
David J. P. Ferguson ◽  
Steven Abel ◽  
Alana Burrrell ◽  
Edward Rea ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Life Cycle ◽  
Live Cell Imaging ◽  
Malaria Parasite ◽  
Cell Imaging ◽  
Male Gamete ◽  
Live Cell ◽  
Basal Bodies ◽  
Parasite Transmission ◽  
Parasite Life Cycle

AbstractEukaryotic flagella are conserved microtubule-based organelles that drive cell motility. Plasmodium, the causative agent of malaria, has a single flagellate stage: the male gamete in the mosquito. Three rounds of endomitotic division together with an unusual mode of flagellum assembly rapidly produce eight motile gametes. These processes are tightly coordinated but their regulation is poorly understood. To understand this important developmental stage, we studied the function and location of the microtubule-based motor kinesin-8B, using gene-targeting, electron microscopy and live cell imaging. Deletion of the kinesin-8B gene showed no effect on mitosis but disrupted 9+2 axoneme assembly and flagellum formation during male gamete development and also completely ablated parasite transmission. Live cell imaging showed that kinesin-8B-GFP did not colocalise with kinetochores in the nucleus but instead revealed dynamic, cytoplasmic localisation with the basal bodies and the assembling axoneme during flagellum formation. We thus uncovered an unexpected role for kinesin-8B in parasite flagellum formation that is vital for the parasite life cycle.

scholarly journals Akt is required for artery formation during embryonic vascular development

2020 ◽  
Author(s):  
Wenping Zhou ◽  
Emma Ristori ◽  
Liqun He ◽  
Joey J Ghersi ◽  
Sameet Mehta ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Vascular Development ◽  
Genetic Process ◽  
Complex Process ◽  
Physiological Relevance ◽  
Embryonic Vascular Development ◽  
Arterial Development ◽  
Notch Activation

SUMMARYOne of the first events in the development of the cardiovascular system is morphogenesis of the main embryonic artery, the dorsal aorta (DA). The DA forms via a conserved genetic process mediated by the migration, specification, and organization of endothelial progenitor cells into a distinct arterial lineage and vessel type. Several angiogenic factors activate different signaling pathways to control DA formation, however the physiological relevance of distinct kinases in this complex process remains unclear. Here, we identify the role of Akt during early vascular development by generating mutant zebrafish lines that lack expression of akt isoforms. Live cell imaging coupled with single cell RNA sequencing of akt mutants reveal that Akt is required for proper development of the DA by sustaining arterial cell progenitor specification and segregation. Mechanistically, inhibition of active FOXO in akt mutants rescues impaired arterial development but not the expression of arterial markers, whereas Notch activation rescues arterial marker expression. Our work suggests that Akt activity is critical for early artery development, in part via FOXO and Notch-mediated regulation.

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