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Eukaryotic Cell Nov 2008
Review
Topics: Animals; Antibodies, Protozoan; Antigens, Protozoan; Disease Models, Animal; Humans; Malaria; Malaria Vaccines; Mice; Plasmodium berghei
PubMed: 18806208
DOI: 10.1128/EC.00242-08 -
Tropical Biomedicine Apr 2011Intracellular parasites manipulate host cell apoptosis in different ways either to increase their life span within infected cells or to spread infection. The present...
Intracellular parasites manipulate host cell apoptosis in different ways either to increase their life span within infected cells or to spread infection. The present data provided information on the cellular changes taking place in spleen and peripheral blood during Plasmodium berghei-infection and indicated apoptosis mediated host immune response during infection. Our results suggested a significant change in cellular composition and absolute number of white blood cells in spleen and peripheral blood of P. berghei-infected Balb/c mice. Plasmodium berghei-infection was associated with marked increase in percentage of apoptotic mononuclear cells compared to polymorphonuclear white blood cells.
Topics: Animals; Apoptosis; Blood; Female; Leukocytes; Malaria; Male; Mice; Mice, Inbred BALB C; Plasmodium berghei; Spleen
PubMed: 21602777
DOI: No ID Found -
The American Journal of Pathology Jan 2010Plasmodium parasites lacking plasmepsin 4 (PM4), an aspartic protease that functions in the lysosomal compartment and contributes to hemoglobin digestion, have only a...
Plasmodium parasites lacking plasmepsin 4 (PM4), an aspartic protease that functions in the lysosomal compartment and contributes to hemoglobin digestion, have only a modest decrease in the asexual blood-stage growth rate; however, PM4 deficiency in the rodent malaria parasite Plasmodium berghei results in significantly less virulence than that for the parental parasite. P. berghei Deltapm4 parasites failed to induce experimental cerebral malaria (ECM) in ECM-susceptible mice, and ECM-resistant mice were able to clear infections. Furthermore, after a single infection, all convalescent mice were protected against subsequent parasite challenge for at least 1 year. Real-time in vivo parasite imaging and splenectomy experiments demonstrated that protective immunity acted through antibody-mediated parasite clearance in the spleen. This work demonstrates, for the first time, that a single Plasmodium gene disruption can generate virulence-attenuated parasites that do not induce cerebral complications and, moreover, are able to stimulate strong protective immunity against subsequent challenge with wild-type parasites. Parasite blood-stage attenuation should help identify protective immune responses against malaria, unravel parasite-derived factors involved in malarial pathologies, such as cerebral malaria, and potentially pave the way for blood-stage whole organism vaccines.
Topics: Animals; Antibodies; Aspartic Acid Endopeptidases; Brain; Immunity; Life Cycle Stages; Luciferases; Malaria; Mice; Mutation; Parasites; Phenotype; Plasmodium berghei; Spleen; Virulence
PubMed: 20019192
DOI: 10.2353/ajpath.2010.090504 -
PLoS Pathogens May 2018Within the liver a single Plasmodium parasite transforms into thousands of blood-infective forms to cause malaria. Here, we use RNA-sequencing to identify host genes...
Within the liver a single Plasmodium parasite transforms into thousands of blood-infective forms to cause malaria. Here, we use RNA-sequencing to identify host genes that are upregulated upon Plasmodium berghei infection of hepatocytes with the hypothesis that host pathways are hijacked to benefit parasite development. We found that expression of aquaporin-3 (AQP3), a water and glycerol channel, is significantly induced in Plasmodium-infected hepatocytes compared to uninfected cells. This aquaglyceroporin localizes to the parasitophorous vacuole membrane, the compartmental interface between the host and pathogen, with a temporal pattern that correlates with the parasite's expansion in the liver. Depletion or elimination of host AQP3 expression significantly reduces P. berghei parasite burden during the liver stage and chemical disruption by a known AQP3 inhibitor, auphen, reduces P. falciparum asexual blood stage and P. berghei liver stage parasite load. Further use of this inhibitor as a chemical probe suggests that AQP3-mediated nutrient transport is an important function for parasite development. This study reveals a previously unknown potential route for host-dependent nutrient acquisition by Plasmodium which was discovered by mapping the transcriptional changes that occur in hepatocytes throughout P. berghei infection. The dataset reported may be leveraged to identify additional host factors that are essential for Plasmodium liver stage infection and highlights Plasmodium's dependence on host factors within hepatocytes.
Topics: Animals; Aquaporin 3; Hep G2 Cells; Hepatocytes; Humans; Liver; Liver Diseases; Malaria; Mice; Parasites; Plasmodium berghei; Protozoan Proteins; Sequence Analysis, RNA; Sporozoites; Vacuoles
PubMed: 29775485
DOI: 10.1371/journal.ppat.1007057 -
Molecular & Cellular Proteomics : MCP Sep 2016Malaria transmission from an infected host to the mosquito vector requires the uptake of intraerythrocytic sexual precursor cells into the mosquito midgut. For the...
Proteomic Analysis of the Plasmodium berghei Gametocyte Egressome and Vesicular bioID of Osmiophilic Body Proteins Identifies Merozoite TRAP-like Protein (MTRAP) as an Essential Factor for Parasite Transmission.
Malaria transmission from an infected host to the mosquito vector requires the uptake of intraerythrocytic sexual precursor cells into the mosquito midgut. For the release of mature extracellular gametes two membrane barriers-the parasite parasitophorous vacuole membrane and the host red blood cell membrane-need to be dissolved. Membrane lysis occurs after the release of proteins from specialized secretory vesicles including osmiophilic bodies. In this study we conducted proteomic analyses of the P. berghei gametocyte egressome and developed a vesicular bioID approach to identify hitherto unknown proteins with a potential function in gametocyte egress. This first Plasmodium gametocyte egressome includes the proteins released by the parasite during the lysis of the parasitophorous vacuole membrane and red blood cell membrane. BioID of the osmiophilic body protein MDV1/PEG3 revealed a vesicular proteome of these gametocyte-specific secretory vesicles. Fluorescent protein tagging and gene deletion approaches were employed to validate and identify a set of novel factors essential for this lysis and egress process. Our study provides the first in vivo bioID for a rodent malaria parasite and together with the first Plasmodium gametocyte egressome identifies MTRAP as a novel factor essential for mosquito transmission. Our data provide an important resource for proteins potentially involved in a key step of gametogenesis.
Topics: Animals; Erythrocyte Membrane; Life Cycle Stages; Malaria; Mass Spectrometry; Mice; Plasmodium berghei; Proteomics; Protozoan Proteins
PubMed: 27371728
DOI: 10.1074/mcp.M116.058263 -
Microbes and Infection Aug 2012The 3'-5'-cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) is the main mediator of cGMP signalling in the malaria parasite. This article reviews the... (Review)
Review
The 3'-5'-cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) is the main mediator of cGMP signalling in the malaria parasite. This article reviews the role of PKG in Plasmodium falciparum during gametogenesis and blood stage schizont rupture, as well as the role of the Plasmodium berghei orthologue in ookinete differentiation and motility, and liver stage schizont development. The current views on potential effector proteins downstream of PKG and the mechanisms that may regulate cyclic nucleotide levels are presented.
Topics: Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Gene Expression Regulation; Plasmodium berghei; Plasmodium falciparum; Signal Transduction
PubMed: 22613210
DOI: 10.1016/j.micinf.2012.04.011 -
Nature Communications Nov 2020Plasmodium parasites possess a translocon that exports parasite proteins into the infected erythrocyte. Although the translocon components are also expressed during the...
Plasmodium parasites possess a translocon that exports parasite proteins into the infected erythrocyte. Although the translocon components are also expressed during the mosquito and liver stage of infection, their function remains unexplored. Here, using a combination of genetic and chemical assays, we show that the translocon component Exported Protein 2 (EXP2) is critical for invasion of hepatocytes. EXP2 is a pore-forming protein that is secreted from the sporozoite upon contact with the host cell milieu. EXP2-deficient sporozoites are impaired in invasion, which can be rescued by the exogenous administration of recombinant EXP2 and alpha-hemolysin (an S. aureus pore-forming protein), as well as by acid sphingomyelinase. The latter, together with the negative impact of chemical and genetic inhibition of acid sphingomyelinase on invasion, reveals that EXP2 pore-forming activity induces hepatocyte membrane repair, which plays a key role in parasite invasion. Overall, our findings establish a novel and critical function for EXP2 that leads to an active participation of the host cell in Plasmodium sporozoite invasion, challenging the current view of the establishment of liver stage infection.
Topics: Animals; Hepatocytes; Humans; Liver; Malaria; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Plasmodium berghei; Protein Transport; Protozoan Proteins; Sporozoites
PubMed: 33159090
DOI: 10.1038/s41467-020-19492-4 -
MBio Nov 2020The recent emergence of parasite resistance to the first line antimalarial drug artemisinin is of particular concern. Artemisinin resistance is primarily driven by...
The recent emergence of parasite resistance to the first line antimalarial drug artemisinin is of particular concern. Artemisinin resistance is primarily driven by mutations in the K13 protein, which enhance survival of early ring-stage parasites treated with the artemisinin active metabolite dihydroartemisinin and associate with delayed parasite clearance However, association of K13 mutations with artemisinin resistance has been problematic due to the absence of a tractable model. Herein, we have employed CRISPR/Cas9 genome editing to engineer selected orthologous K13 mutations into the gene of an artemisinin-sensitive rodent model of malaria. Introduction of the orthologous K13 F446I, M476I, Y493H, and R539T mutations into K13 yielded gene-edited parasites with reduced susceptibility to dihydroartemisinin in the standard 24-h assay and increased survival in an adapted ring-stage survival assay. Mutant K13 parasites also displayed delayed clearance upon treatment with artesunate and achieved faster recrudescence upon treatment with artemisinin. Orthologous C580Y and I543T mutations could not be introduced into , while the equivalents of the M476I and R539T mutations resulted in significant growth defects. Furthermore, a -selective proteasome inhibitor strongly synergized dihydroartemisinin action in these K13 mutant lines, providing further evidence that the proteasome can be targeted to overcome artemisinin resistance. Taken together, our findings provide clear experimental evidence for the involvement of K13 polymorphisms in mediating susceptibility to artemisinins and, most importantly, under conditions. Recent successes in malaria control have been seriously threatened by the emergence of parasite resistance to the frontline artemisinin drugs in Southeast Asia. artemisinin resistance is associated with mutations in the parasite K13 protein, which associates with a delay in the time required to clear the parasites upon drug treatment. Gene editing technologies have been used to validate the role of several candidate K13 mutations in mediating artemisinin resistance under laboratory conditions. Nonetheless, the causal role of these mutations under conditions has been a matter of debate. Here, we have used CRISPR/Cas9 gene editing to introduce K13 mutations associated with artemisinin resistance into the related rodent-infecting parasite, Phenotyping of these K13 mutant parasites provides evidence of their role in mediating artemisinin resistance , which supports artemisinin resistance observations. However, we were unable to introduce some of the K13 mutations (C580Y and I543T) into the corresponding amino acid residues, while other introduced mutations (M476I and R539T equivalents) carried pronounced fitness costs. Our study provides evidence of a clear causal role of K13 mutations in modulating susceptibility to artemisinins and using the well-characterized model. We also show that inhibition of the proteasome offsets parasite resistance to artemisinins in these mutant lines.
Topics: Animals; Antimalarials; Artemisinins; Drug Resistance; Female; Humans; Malaria; Mice; Mutation; Plasmodium berghei; Plasmodium falciparum; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Protozoan Proteins
PubMed: 33173001
DOI: 10.1128/mBio.02312-20 -
Phosphorylation of myosin A regulates gliding motility and is essential for Plasmodium transmission.EMBO Reports Jul 2022Malaria-causing parasites rely on an actin-myosin-based motor for the invasion of different host cells and tissue traversal in mosquitoes and vertebrates. The unusual...
Malaria-causing parasites rely on an actin-myosin-based motor for the invasion of different host cells and tissue traversal in mosquitoes and vertebrates. The unusual myosin A of Plasmodium spp. has a unique N-terminal extension, which is important for red blood cell invasion by P. falciparum merozoites in vitro and harbors a phosphorylation site at serine 19. Here, using the rodent-infecting P. berghei we show that phosphorylation of serine 19 increases ookinete but not sporozoite motility and is essential for efficient transmission of Plasmodium by mosquitoes as S19A mutants show defects in mosquito salivary gland entry. S19A along with E6R mutations slow ookinetes and salivary gland sporozoites in both 2D and 3D environments. In contrast to data from purified proteins, both E6R and S19D mutations lower force generation by sporozoites. Our data show that the phosphorylation cycle of S19 influences parasite migration and force generation and is critical for optimal migration of parasites during transmission from and to the mosquito.
Topics: Animals; Culicidae; Malaria, Falciparum; Nonmuscle Myosin Type IIA; Phosphorylation; Plasmodium berghei; Protozoan Proteins; Serine; Sporozoites
PubMed: 35506479
DOI: 10.15252/embr.202254857 -
Malaria Journal Mar 2012Plasmodium has a complex cell biology and it is essential to dissect the cell-signalling pathways underlying its survival within the host.
BACKGROUND
Plasmodium has a complex cell biology and it is essential to dissect the cell-signalling pathways underlying its survival within the host.
METHODS
Using the fluorescence resonance energy transfer (FRET) peptide substrate Abz-AIKFFARQ-EDDnp and Fluo4/AM, the effects of extracellular ATP on triggering proteolysis and Ca²⁺ signalling in Plasmodium berghei and Plasmodium yoelii malaria parasites were investigated.
RESULTS
The protease activity was blocked in the presence of the purinergic receptor blockers suramin (50 μM) and PPADS (50 μM) or the extracellular and intracellular calcium chelators EGTA (5 mM) and BAPTA/AM (25, 100, 200 and 500 μM), respectively for P. yoelii and P. berghei. Addition of ATP (50, 70, 200 and 250 μM) to isolated parasites previously loaded with Fluo4/AM in a Ca²⁺-containing medium led to an increase in cytosolic calcium. This rise was blocked by pre-incubating the parasites with either purinergic antagonists PPADS (50 μM), TNP-ATP (50 μM) or the purinergic blockers KN-62 (10 μM) and Ip5I (10 μM). Incubating P. berghei infected cells with KN-62 (200 μM) resulted in a changed profile of merozoite surface protein 1 (MSP1) processing as revealed by western blot assays. Moreover incubating P. berghei for 17 h with KN-62 (10 μM) led to an increase in rings forms (82% ± 4, n = 11) and a decrease in trophozoite forms (18% ± 4, n = 11).
CONCLUSIONS
The data clearly show that purinergic signalling modulates P. berghei protease(s) activity and that MSP1 is one target in this pathway.
Topics: Adenosine Triphosphate; Aniline Compounds; Calcium; Peptides; Plasmodium berghei; Plasmodium yoelii; Proteolysis; Signal Transduction; Staining and Labeling; Xanthenes
PubMed: 22420332
DOI: 10.1186/1475-2875-11-69