scholarly journals CRISPR/Cas9-engineered inducible gametocyte producer lines as a novel tool for basic and applied research on Plasmodium falciparum malaria transmission stages

2020 ◽  
Author(s):  
Sylwia Boltryk ◽  
Armin Passecker ◽  
Arne Alder ◽  
Marga van de Vegte-Bolmer ◽  
Robert Sauerwein ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Applied Research ◽  
Plasmodium Falciparum Malaria ◽  
Mosquito Vector ◽  
Large Numbers ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Invaluable Tool ◽  
Marker Free ◽  
Basic And Applied Research

Abstract The malaria parasite Plasmodium falciparum replicates inside erythrocytes in the blood of infected humans. During each replication cycle, a small proportion of parasites commits to sexual development and differentiates into gametocytes, which are essential for parasite transmission to other human hosts via the mosquito vector. Detailed molecular investigation of gametocyte biology and transmission has been hampered by difficulties in generating large numbers of these highly specialized cells. Here, we engineered marker-free P. falciparum inducible gametocyte producer (iGP) lines for the routine mass production of synchronous gametocytes. Through targeted overexpression of the sexual commitment factor GDV1, iGP lines consistently achieve sexual commitment rates of 75% and produce gametocytes that are infectious to mosquitoes. Subsequent tagging of a nucleoporin allowed us to visualize marked nuclear transformations during gametocytogenesis and demonstrates that further genetic engineering of iGP lines is an invaluable tool for the targeted exploration of gametocyte biology. We believe the iGP approach developed here opens up unprecedented opportunities that will expedite future basic and applied research on P. falciparum transmission stages.

scholarly journals CRISPR/Cas9-engineered inducible gametocyte producer lines as a novel tool for basic and applied research on Plasmodium falciparum malaria transmission stages

2020 ◽  
Author(s):  
Sylwia D. Boltryk ◽  
Armin Passecker ◽  
Arne Alder ◽  
Marga van de Vegte-Bolmer ◽  
Robert W. Sauerwein ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Applied Research ◽  
Plasmodium Falciparum Malaria ◽  
Mosquito Vector ◽  
Parasite Transmission ◽  
Large Numbers ◽  
Molecular Investigation ◽  
Invaluable Tool ◽  
Marker Free ◽  
Basic And Applied Research

AbstractThe malaria parasite Plasmodium falciparum replicates inside erythrocytes in the blood of infected humans. During each replication cycle, a small proportion of parasites commits to sexual development and differentiates into gametocytes, which are essential for parasite transmission to other human hosts via the mosquito vector. Detailed molecular investigation of gametocyte biology and transmission has been hampered by difficulties in generating large numbers of these highly specialized cells. Here, we engineered marker-free P. falciparum inducible gametocyte producer (iGP) lines for the routine mass production of synchronous gametocytes. Through targeted overexpression of the sexual commitment factor GDV1, iGP lines consistently achieve sexual commitment rates of 75% and produce gametocytes that are infectious to mosquitoes. Subsequent tagging of a nucleoporin allowed us to visualize marked nuclear transformations during gametocytogenesis and demonstrates that further genetic engineering of iGP lines is an invaluable tool for the targeted exploration of gametocyte biology. We believe the iGP approach developed here opens up unprecedented opportunities that will expedite future basic and applied research on P. falciparum transmission stages.

scholarly journals Revisiting gametocyte biology in malaria parasites

2019 ◽  
Vol 43 (4) ◽  
pp. 401-414 ◽  
Author(s):  
Priscilla Ngotho ◽  
Alexandra Blancke Soares ◽  
Franziska Hentzschel ◽  
Fiona Achcar ◽  
Lucia Bertuccini ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Blood Circulation ◽  
Malaria Parasite ◽  
Mosquito Vector ◽  
Human Malaria Parasite ◽  
Malaria Burden ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Low Levels ◽  
Transmission Biology

ABSTRACT Gametocytes are the only form of the malaria parasite that is transmissible to the mosquito vector. They are present at low levels in blood circulation and significant knowledge gaps exist in their biology. Recent reductions in the global malaria burden have brought the possibility of elimination and eradication, with renewed focus on malaria transmission biology as a basis for interventions. This review discusses recent insights into gametocyte biology in the major human malaria parasite, Plasmodium falciparum and related species.

scholarly journals Disruption of the PfPK7 Gene Impairs Schizogony and Sporogony in the Human Malaria Parasite Plasmodium falciparum

2007 ◽  
Vol 7 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Dominique Dorin-Semblat ◽  
Audrey Sicard ◽  
Caroline Doerig ◽  
Lisa Ranford-Cartwright ◽  
Christian Doerig
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Kinase ◽  
Reverse Genetics ◽  
Mitogen Activated Protein Kinase ◽  
Mosquito Vector ◽  
Human Malaria Parasite ◽  
Parasite Plasmodium ◽  
Mitogen Activated Protein ◽  
Parasite Plasmodium Falciparum ◽  
Two Stages

ABSTRACT PfPK7 is an orphan protein kinase of Plasmodium falciparum with maximal homology to MEK3/6 and to fungal protein kinase A proteins in its C-terminal and N-terminal regions, respectively. We showed previously that recombinant PfPK7 is active on various substrates but is unable to phosphorylate the Plasmodium falciparum mitogen-activated protein kinase homologues, suggesting that it is not a MEK functional homologue. Using a reverse genetics approach to investigate the function of this enzyme in live parasites, we now show that PfPK7 − parasite clones display phenotypes at two stages of their life cycle: first, a decrease in the rate of asexual growth in erythrocytes associated with a lower number of daughter merozoites generated per schizont, and second, a dramatic reduction in the ability to produce oocysts in the mosquito vector. A normal asexual growth rate and the ability to produce oocysts are restored if a functional copy of the PfPK7 gene is reintroduced into the PfPK7 − parasites. Hence, PfPK7 is involved in a pathway that regulates parasite proliferation and development.

Glutathione export from human erythrocytes and Plasmodium falciparum malaria parasites

2012 ◽  
Vol 448 (3) ◽  
pp. 389-400 ◽  
Author(s):  
Margery A. Barrand ◽  
Markus Winterberg ◽  
Frances Ng ◽  
Mai Nguyen ◽  
Kiaran Kirk ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Falciparum Malaria ◽  
Human Erythrocytes ◽  
Multidrug Resistance Proteins ◽  
Resistance Proteins ◽  
Physiological Conditions ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Oxidative Challenge ◽  
New Permeability Pathways

Glutathione export from uninfected human erythrocytes was compared with that from cells infected with the malaria parasite Plasmodium falciparum using two separate methods that distinguish between oxidized (GSSG) and reduced (GSH) glutathione. One involved enzymatic recycling with or without thiol-masking; the other involved rapid derivatization followed by HPLC. Glutathione efflux from uninfected erythrocytes under physiological conditions occurred predominantly as GSH. On exposure of the cells to oxidative challenge, efflux of GSSG exceeded that of GSH. Efflux of both species was blocked by MK571, an inhibitor of mammalian multidrug-resistance proteins. Glutathione efflux from parasitized erythrocytes was substantially greater than that from uninfected erythrocytes. Under physiological conditions, the exported species was GSH, whereas under energy-depleted conditions, GSSG efflux occurred. Glutathione export from parasitized cells was inhibited partially by MK571 and more so by furosemide, an inhibitor of the ‘new permeability pathways’ induced by the parasite in the host erythrocyte membrane. Efflux from isolated parasites occurred as GSH. On exposure to oxidative challenge, this GSH efflux decreased, but no GSSG export was detected. These results are consistent with the view that the parasite supplies its host erythrocyte with GSH, much of which is exported from the infected cell via parasite-induced pathways.

scholarly journals Invasion of mouse erythrocytes by the human malaria parasite, Plasmodium falciparum.

1987 ◽  
Vol 165 (6) ◽  
pp. 1713-1718 ◽  
Author(s):  
F W Klotz ◽  
J D Chulay ◽  
W Daniel ◽  
L H Miller
Keyword(s):  
Plasmodium Falciparum ◽  
Sialic Acid ◽  
Falciparum Malaria ◽  
Vaccine Development ◽  
Plasmodium Falciparum Malaria ◽  
Human Erythrocytes ◽  
Human Malaria Parasite ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum

Plasmodium falciparum malaria merozoites require erythrocyte sialic acid for optimal invasion of human erythrocytes. Since mouse erythrocytes have the form of sialic acid found on human erythrocytes (N-acetyl neuraminic acid), mouse erythrocytes were tested for invasion in vitro. The Camp and 7G8 strains of P. falciparum invaded mouse erythrocytes at 17-45% of the invasion rate of human erythrocytes. Newly invaded mouse erythrocytes morphologically resembled parasitized human erythrocytes as shown on Giemsa-stained blood films and by electron microscopy. The rim of parasitized mouse erythrocytes contained the P. falciparum 155-kD protein, which is on the rim of ring-infected human erythrocytes. Camp but not 7G8 invaded rat erythrocytes, indicating receptor heterogeneity. These data suggest that it may be possible to adapt the asexual erythrocytic stage of P. falciparum to rodents. The development of a rodent model of P. falciparum malaria could facilitate vaccine development.

scholarly journals CRISPR/Cas9-engineered inducible gametocyte producer lines as a valuable tool for Plasmodium falciparum malaria transmission research

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sylwia D. Boltryk ◽  
Armin Passecker ◽  
Arne Alder ◽  
Eilidh Carrington ◽  
Marga van de Vegte-Bolmer ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Sexual Development ◽  
Mass Production ◽  
Plasmodium Falciparum Malaria ◽  
Mosquito Vector ◽  
Parasite Transmission ◽  
Large Numbers ◽  
Molecular Investigation ◽  
Transmission Stage

AbstractThe malaria parasite Plasmodium falciparum replicates inside erythrocytes in the blood of infected humans. During each replication cycle, a small proportion of parasites commits to sexual development and differentiates into gametocytes, which are essential for parasite transmission via the mosquito vector. Detailed molecular investigation of gametocyte biology and transmission has been hampered by difficulties in generating large numbers of these highly specialised cells. Here, we engineer P. falciparum NF54 inducible gametocyte producer (iGP) lines for the routine mass production of synchronous gametocytes via conditional overexpression of the sexual commitment factor GDV1. NF54/iGP lines consistently achieve sexual commitment rates of 75% and produce viable gametocytes that are transmissible by mosquitoes. We also demonstrate that further genetic engineering of NF54/iGP parasites is a valuable tool for the targeted exploration of gametocyte biology. In summary, we believe the iGP approach developed here will greatly expedite basic and applied malaria transmission stage research.

scholarly journals Targeting Gametocytes of the Malaria Parasite Plasmodium falciparum in a Functional Genomics Era: Next Steps

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 346
Author(s):  
Jyotsna Chawla ◽  
Jenna Oberstaller ◽  
John H. Adams
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Genetic Factors ◽  
Therapeutic Interventions ◽  
Mosquito Vector ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Stage Development ◽  
Transmission Biology ◽  
Made In

Mosquito transmission of the deadly malaria parasite Plasmodium falciparum is mediated by mature sexual forms (gametocytes). Circulating in the vertebrate host, relatively few intraerythrocytic gametocytes are picked up during a bloodmeal to continue sexual development in the mosquito vector. Human-to-vector transmission thus represents an infection bottleneck in the parasite’s life cycle for therapeutic interventions to prevent malaria. Even though recent progress has been made in the identification of genetic factors linked to gametocytogenesis, a plethora of genes essential for sexual-stage development are yet to be unraveled. In this review, we revisit P. falciparum transmission biology by discussing targetable features of gametocytes and provide a perspective on a forward-genetic approach for identification of novel transmission-blocking candidates in the future.

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