Rodent Malaria Erythrocyte Preference Assessment by an Ex Vivo Tropism Assay

Circulating red blood cells consist of young erythrocytes (early and late reticulocytes) and mature erythrocytes (normocytes). The human malaria parasites, Plasmodium falciparum and P. vivax, have a preference to invade reticulocytes during blood-stage infection. Rodent malaria parasites that also prefer reticulocytes could be useful tools to study human malaria reticulocyte invasion. However, previous tropism studies of rodent malaria are inconsistent from one another, making it difficult to compare cell preference of different parasite species and strains. In vivo measurements of cell tropism are also subjected to many confounding factors. Here we developed an ex vivo tropism assay for rodent malaria with highly purified fractions of murine reticulocytes and normocytes. We measured invasion into the different erythrocyte populations using flow cytometry and evaluated the tropism index of the parasite strains. We found that P. berghei ANKA displayed the strongest reticulocyte preference, followed by P. yoelii 17X1.1, whereas P. chabaudi AS and P. vinckei S67 showed mixed tropism. These preferences are intrinsic and were maintained at different reticulocyte and normocyte availabilities. Our study shed light on the true erythrocyte preference of the parasites and paves the way for future investigations on the receptor-ligand interactions mediating erythrocyte tropism.

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Ex VivoMaturation Assay for Testing Antimalarial Sensitivity of Rodent Malaria Parasites

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01292-16 ◽

2016 ◽

Vol 60 (11) ◽

pp. 6859-6866 ◽

Cited By ~ 4

Author(s):

Zi Wei Chang ◽

Benoit Malleret ◽

Bruce Russell ◽

Laurent Rénia ◽

Carla Claser

Keyword(s):

Ex Vivo ◽

Single Step ◽

Parasite Development ◽

Ring Stage ◽

Malaria Parasites ◽

Rodent Malaria ◽

Content Type ◽

Parasite Biology

ABSTRACTEx vivoassay systems provide a powerful approach to studying human malaria parasite biology and to testing antimalarials. For rodent malaria parasites, short-termin vitroculture andex vivoantimalarial susceptibility assays are relatively cumbersome, relying onin vivopassage for synchronization, since ring-stage parasites are an essential starting material. Here, we describe a new approach based on the enrichment of ring-stagePlasmodium berghei,P. yoelii, andP. vinckei vinckeiusing a single-step Percoll gradient. Importantly, we demonstrate that the enriched ring-stage parasites develop synchronously regardless of the parasite strain or species used. Using a flow cytometry assay with Hoechst and ethidium or MitoTracker dye, we show that parasite development is easily and rapidly monitored. Finally, we demonstrate that this approach can be used to screen antimalarial drugs.

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Extrahepatic Exoerythrocytic Forms of Rodent Malaria Parasites at the Site of Inoculation: Clearance after Immunization, Susceptibility to Primaquine, and Contribution to Blood-Stage Infection

Infection and Immunity ◽

10.1128/iai.00246-12 ◽

2012 ◽

Vol 80 (6) ◽

pp. 2158-2164 ◽

Cited By ~ 30

Author(s):

Tatiana Voza ◽

Jessica L. Miller ◽

Stefan H. I. Kappe ◽

Photini Sinnis

Keyword(s):

Common Property ◽

Adaptive Immune Response ◽

Plasmodium Yoelii ◽

Blood Stage ◽

Mammalian Host ◽

Malaria Parasites ◽

Rodent Malaria ◽

Content Type ◽

Blood Stage Infection ◽

Stage Infection

ABSTRACTPlasmodiumsporozoites are inoculated into the skin of the mammalian host as infected mosquitoes probe for blood. A proportion of the inoculum enters the bloodstream and goes to the liver, where the sporozoites invade hepatocytes and develop into the next life cycle stage, the exoerythrocytic, or liver, stage. Here, we show that a small fraction of the inoculum remains in the skin and begins to develop into exoerythrocytic forms that can persist for days. Skin exoerythrocytic forms were observed for bothPlasmodium bergheiandPlasmodium yoelii, two different rodent malaria parasites, suggesting that development in the skin of the mammalian host may be a common property of plasmodia. Our studies demonstrate that skin exoerythrocytic stages are susceptible to destruction in immunized mice, suggesting that their aberrant location does not protect them from the host's adaptive immune response. However, in contrast to their hepatic counterparts, they are not susceptible to primaquine. We took advantage of their resistance to primaquine to test whether they could initiate a blood-stage infection directly from the inoculation site, and our data indicate that these stages are not able to initiate malaria infection.

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A cornucopia of research resources for the fourth rodent malaria parasite species

BMC Biology ◽

10.1186/s12915-021-01019-y ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Jane M. Carlton

Keyword(s):

Malaria Parasite ◽

Parasite Species ◽

First Century ◽

Model Systems ◽

Rodent Malaria Parasite ◽

Malaria Parasites ◽

Rodent Malaria ◽

Human Malaria ◽

Plasmodium Vinckei ◽

Research Resources

AbstractThe study of human malaria caused by species of Plasmodium has undoubtedly been enriched by the use of model systems, such as the rodent malaria parasites originally isolated from African thicket rats. A significant gap in the arsenal of resources of the species that make up the rodent malaria parasites has been the lack of any such tools for the fourth of the species, Plasmodium vinckei. This has recently been rectified by Abhinay Ramaprasad and colleagues, whose pivotal paper published in BMC Biology describes a cornucopia of new P. vinckei ‘omics datasets, mosquito transmission experiments, transfection protocols, and virulence phenotypes, to propel this species firmly into the twenty-first century.

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Real-time in vivo imaging of transgenic bioluminescent blood stages of rodent malaria parasites in mice

Nature Protocols ◽

10.1038/nprot.2006.69 ◽

2006 ◽

Vol 1 (1) ◽

pp. 476-485 ◽

Cited By ~ 67

Author(s):

Blandine Franke-Fayard ◽

Andrew P Waters ◽

Chris J Janse

Keyword(s):

Real Time ◽

In Vivo Imaging ◽

Malaria Parasites ◽

Rodent Malaria

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Quantitative intravital imaging of Plasmodium falciparum sporozoites: A novel platform to test malaria intervention strategies

10.1101/716878 ◽

2019 ◽

Cited By ~ 2

Author(s):

Christine S. Hopp ◽

Sachie Kanatani ◽

Nathan K. Archer ◽

Robert J. Miller ◽

Haiyun Liu ◽

...

Keyword(s):

Xenograft Model ◽

Mouse Skin ◽

Intervention Strategies ◽

Rodent Malaria ◽

Human Malaria ◽

Drug Candidates ◽

Detection And Tracking ◽

Species Specific ◽

Skin Xenograft

AbstractMalaria infection starts with the injection of motile Plasmodium sporozoites into the host’s skin during a mosquito bite. Previous studies using the rodent malaria model indicate that the dermal inoculation site may be where sporozoites are most vulnerable to antibodies, yet, functional in vivo assays with human malaria parasites are lacking. Here, we present the first characterization of P. falciparum sporozoites in the skin, comparing their motility to two rodent malaria species and investigating whether the environment of its natural host influences P. falciparum sporozoite motility using a human skin xenograft model. The combined data suggest that in contrast to the liver and blood stages, the skin is not a species-specific barrier for Plasmodium. We observe that P. falciparum sporozoites inoculated into mouse skin move with similar speed, displacement and duration, and enter blood vessels in similar numbers as the rodent parasites. Thus, interventions targeting P. falciparum sporozoite migration can be tested in the murine dermis. Importantly, to streamline quantification of sporozoite motility, we developed a toolbox allowing for automated detection and tracking of sporozoites in intravital microscopy videos. This establishes a platform to test vaccine candidates, immunization protocols, monoclonal antibodies and drug candidates for their impact on human malaria sporozoites in vivo. Screening of intervention strategies for in vivo efficacy against Pf sporozoites using this new platform will have the potential to validate targets prior to expensive clinical trials.

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A lipocalin mediates unidirectional heme biomineralization in malaria parasites

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2001153117 ◽

2020 ◽

Vol 117 (28) ◽

pp. 16546-16556

Author(s):

Joachim M. Matz ◽

Benjamin Drepper ◽

Thorsten B. Blum ◽

Eric van Genderen ◽

Alana Burrell ◽

...

Keyword(s):

Parasite Species ◽

Parasite Clearance ◽

Malaria Parasites ◽

Human Malaria Parasite ◽

Human Malaria ◽

Biomineralization Process ◽

Stage Development ◽

Transcriptional Deregulation

During blood-stage development, malaria parasites are challenged with the detoxification of enormous amounts of heme released during the proteolytic catabolism of erythrocytic hemoglobin. They tackle this problem by sequestering heme into bioinert crystals known as hemozoin. The mechanisms underlying this biomineralization process remain enigmatic. Here, we demonstrate that both rodent and human malaria parasite species secrete and internalize a lipocalin-like protein, PV5, to control heme crystallization. Transcriptional deregulation ofPV5in the rodent parasitePlasmodium bergheiresults in inordinate elongation of hemozoin crystals, while conditionalPV5inactivation in the human malaria agentPlasmodium falciparumcauses excessive multidirectional crystal branching. Although hemoglobin processing remains unaffected, PV5-deficient parasites generate less hemozoin. Electron diffraction analysis indicates that despite the distinct changes in crystal morphology, neither the crystalline order nor unit cell of hemozoin are affected by impaired PV5 function. Deregulation ofPV5expression rendersP. bergheihypersensitive to the antimalarial drugs artesunate, chloroquine, and atovaquone, resulting in accelerated parasite clearance following drug treatment in vivo. Together, our findings demonstrate thePlasmodium-tailored role of a lipocalin family member in hemozoin formation and underscore the heme biomineralization pathway as an attractive target for therapeutic exploitation.

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Basigin is a druggable target for host-oriented antimalarial interventions

Journal of Experimental Medicine ◽

10.1084/jem.20150032 ◽

2015 ◽

Vol 212 (8) ◽

pp. 1145-1151 ◽

Cited By ~ 33

Author(s):

Zenon A. Zenonos ◽

Sara K. Dummler ◽

Nicole Müller-Sienerth ◽

Jianzhu Chen ◽

Peter R. Preiser ◽

...

Keyword(s):

Socioeconomic Development ◽

Chimeric Antibody ◽

Infection Model ◽

Drug Resistant ◽

Parasite Invasion ◽

Erythrocyte Invasion ◽

Significant Barrier ◽

Blood Stage Infection ◽

Stage Infection

Plasmodium falciparum is the parasite responsible for the most lethal form of malaria, an infectious disease that causes a large proportion of childhood deaths and poses a significant barrier to socioeconomic development in many countries. Although antimalarial drugs exist, the repeated emergence and spread of drug-resistant parasites limit their useful lifespan. An alternative strategy that could limit the evolution of drug-resistant parasites is to target host factors that are essential and universally required for parasite growth. Host-targeted therapeutics have been successfully applied in other infectious diseases but have never been attempted for malaria. Here, we report the development of a recombinant chimeric antibody (Ab-1) against basigin, an erythrocyte receptor necessary for parasite invasion as a putative antimalarial therapeutic. Ab-1 inhibited the PfRH5-basigin interaction and potently blocked erythrocyte invasion by all parasite strains tested. Importantly, Ab-1 rapidly cleared an established P. falciparum blood-stage infection with no overt toxicity in an in vivo infection model. Collectively, our data demonstrate that antibodies or other therapeutics targeting host basigin could be an effective treatment for patients infected with multi-drug resistant P. falciparum.

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Inhibition by cyclosporin A of rodent malaria in vivo and human malaria in vitro.

Infection and Immunity ◽

10.1128/iai.37.3.1093-1100.1982 ◽

1982 ◽

Vol 37 (3) ◽

pp. 1093-1100 ◽

Cited By ~ 47

Author(s):

S P Nickell ◽

L W Scheibel ◽

G A Cole

Keyword(s):

Cyclosporin A ◽

Rodent Malaria ◽

Human Malaria

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Controlled Human Malaria Infection: Applications, Advances, and Challenges

Infection and Immunity ◽

10.1128/iai.00479-17 ◽

2017 ◽

Vol 86 (1) ◽

Cited By ~ 29

Author(s):

Danielle I. Stanisic ◽

James S. McCarthy ◽

Michael F. Good

Keyword(s):

Drug Development ◽

Malaria Infection ◽

Malaria Vaccine ◽

Blood Stage ◽

Content Type ◽

Human Malaria ◽

Recent Advances ◽

Blood Stage Infection ◽

Controlled Human Malaria Infection ◽

Stage Infection

ABSTRACT Controlled human malaria infection (CHMI) entails deliberate infection with malaria parasites either by mosquito bite or by direct injection of sporozoites or parasitized erythrocytes. When required, the resulting blood-stage infection is curtailed by the administration of antimalarial drugs. Inducing a malaria infection via inoculation with infected blood was first used as a treatment (malariotherapy) for neurosyphilis in Europe and the United States in the early 1900s. More recently, CHMI has been applied to the fields of malaria vaccine and drug development, where it is used to evaluate products in well-controlled early-phase proof-of-concept clinical studies, thus facilitating progression of only the most promising candidates for further evaluation in areas where malaria is endemic. Controlled infections have also been used to immunize against malaria infection. Historically, CHMI studies have been restricted by the need for access to insectaries housing infected mosquitoes or suitable malaria-infected individuals. Evaluation of vaccine and drug candidates has been constrained in these studies by the availability of a limited number of Plasmodium falciparum isolates. Recent advances have included cryopreservation of sporozoites, the manufacture of well-characterized and genetically distinct cultured malaria cell banks for blood-stage infection, and the availability of Plasmodium vivax-specific reagents. These advances will help to accelerate malaria vaccine and drug development by making the reagents for CHMI more widely accessible and also enabling a more rigorous evaluation with multiple parasite strains and species. Here we discuss the different applications of CHMI, recent advances in the use of CHMI, and ongoing challenges for consideration.

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