A novel Plasmodium yoelii pseudokinase, PypPK1, is involved in erythrocyte invasion and exflagellation center formation

Publication date: Available online 14 January 2020Source: Parasitology InternationalAuthor(s): Takahiro Ishizaki, Nattawat Chaiyawong, Hassan Hakimi, Masahito Asada, Mayumi Tachibana, Tomoko Ishino, Kazuhide Yahata, Osamu KanekoAbstractMalaria parasites proliferate by repeated invasion of and multiplication within erythrocytes in the vertebrate host. Sexually committed intraerythrocytic parasites undergo sexual stage differentiation to become gametocytes. After ingestion by the mosquito, male and female gametocytes egress from erythrocytes and fertilize within the mosquito midgut. A complex signaling pathway likely responds to environmental events to trigger gametogenesis and regulate fertilization; however, such knowledge remains limited for malaria parasites. Several pseudokinases are highly transcribed at the gametocyte stage and are possible multi-functional regulators controlling critical steps of the life cycle. Here we characterized one pseudokinase, termed PypPK1, in Plasmodium yoelii that is highly expressed in schizonts and male gametocytes. Immunofluorescence assays for parasites expressing Myc-tagged PypPK1 confirmed that PypPK1 protein is expressed in schizonts and sexual stage parasites. Transgenic ΔpPK1 parasites, in which the PypPK1 gene locus was deleted by the CRISPR/Cas9 method, showed significant growth defect and reduced virulence in mice. In the blood stage, ΔpPK1 parasites were able to egress from erythrocytes similar to wild type parasites;...
Source: Parasitology International - Category: Parasitology Source Type: research

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The infection dynamics between different species of Plasmodium that infect the same human host can both suppress and exacerbate disease. This could arise from inter-parasite interactions, such as competition, from immune regulation, or both. The occurrence of protective, cross-species (heterologous) immunity is an unlikely event, especially considering that strain-transcending immunity within a species is only partial despite lifelong exposure to that species. Here we review the literature in humans and animal models to identify the contexts where heterologous immunity can arise, and which antigens may be involved. From th...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
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Source: Advances in Hematology - Category: Hematology Tags: Adv Hematol Source Type: research
Malaria is one of the three most lethal infectious diseases. Unlike AIDS and tuberculosis, malaria is unique in that the parasite must complete a complex differentiation program in its mosquito vector for transmission to occur (1) (Fig. 1). Despite significant progress made in the last couple of decades, our mechanistic...
Source: Proceedings of the National Academy of Sciences - Category: Science Authors: Tags: Commentaries Source Type: research
ira A Abstract Artemether-lumefantrine (AL) is the first-line treatment for uncomplicated Plasmodium falciparum infection in Colombia. To assess AL efficacy for uncomplicated falciparum malaria in Quibdo, Choco, Colombia, we conducted a 28-day therapeutic efficacy study (TES) following the WHO guidelines. From July 2018 to February 2019, febrile patients aged 5-65 years with microscopy-confirmed P. falciparum mono-infection and asexual parasite density of 250-100,000 parasites/µL were enrolled and treated with a supervised 3-day course of AL. The primary endpoint was adequate clinical and parasitological res...
Source: Am J Trop Med Hyg - Category: Infectious Diseases Authors: Tags: Am J Trop Med Hyg Source Type: research
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Source: Journal of Immunology Research - Category: Allergy & Immunology Tags: J Immunol Res Source Type: research
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Source: GEO: Gene Expression Omnibus - Category: Genetics & Stem Cells Tags: Expression profiling by high throughput sequencing Homo sapiens Plasmodium berghei Source Type: research
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Source: Acta Pharmaceutica - Category: Drugs & Pharmacology Authors: Tags: Acta Pharm Source Type: research
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Source: Military Medicine - Category: International Medicine & Public Health Tags: Mil Med Source Type: research
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Source: Malaria Journal - Category: Infectious Diseases Authors: Tags: Research Source Type: research
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Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
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