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Anderson DC, Peterson MS, Lapp SA, Galinski MR. Proteomes of plasmodium knowlesi early and late ring-stage parasites and infected host erythrocytes. J Proteomics 2024; 302:105197. [PMID: 38759952 DOI: 10.1016/j.jprot.2024.105197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 05/05/2024] [Accepted: 05/14/2024] [Indexed: 05/19/2024]
Abstract
The emerging malaria parasite Plasmodium knowlesi threatens the goal of worldwide malaria elimination due to its zoonotic spread in Southeast Asia. After brief ex-vivo culture we used 2D LC/MS/MS to examine the early and late ring stages of infected Macaca mulatta red blood cells harboring P. knowlesi. The M. mulatta clathrin heavy chain and T-cell and macrophage inhibitor ERMAP were overexpressed in the early ring stage; glutaredoxin 3 was overexpressed in the late ring stage; GO term differential enrichments included response to oxidative stress and the cortical cytoskeleton in the early ring stage. P. knowlesi clathrin heavy chain and 60S acidic ribosomal protein P2 were overexpressed in the late ring stage; GO term differential enrichments included vacuoles in the early ring stage, ribosomes and translation in the late ring stage, and Golgi- and COPI-coated vesicles, proteasomes, nucleosomes, vacuoles, ion-, peptide-, protein-, nucleocytoplasmic- and RNA-transport, antioxidant activity and glycolysis in both stages. SIGNIFICANCE: Due to its zoonotic spread, cases of the emerging human pathogen Plasmodium knowlesi in southeast Asia, and particularly in Malaysia, threaten regional and worldwide goals for malaria elimination. Infection by this parasite can be fatal to humans, and can be associated with significant morbidity. Due to zoonotic transmission from large macaque reservoirs that are untreatable by drugs, and outdoor biting mosquito vectors that negate use of preventive measures such as bed nets, its containment remains a challenge. Its biology remains incompletely understood. Thus we examine the expressed proteome of the early and late ex-vivo cultured ring stages, the first intraerythrocyte developmental stages after infection of host rhesus macaque erythrocytes. We used GO term enrichment strategies and differential protein expression to compare early and late ring stages. The early ring stage is characterized by the enrichment of P. knowlesi vacuoles, and overexpression of the M. mulatta clathrin heavy chain, important for clathrin-coated pits and vesicles, and clathrin-mediated endocytosis. The M. mulatta protein ERMAP was also overexpressed in the early ring stage, suggesting a potential role in early ring stage inhibition of T-cells and macrophages responding to P. knowlesi infection of reticulocytes. This could allow expansion of the host P. knowlesi cellular niche, allowing parasite adaptation to invasion of a wider age range of RBCs than the preferred young RBCs or reticulocytes, resulting in proliferation and increased pathogenesis in infected humans. Other GO terms differentially enriched in the early ring stage include the M. mulatta cortical cytoskeleton and response to oxidative stress. The late ring stage is characterized by overexpression of the P. knowlesi clathrin heavy chain. Combined with late ring stage GO term enrichment of Golgi-associated and coated vesicles, and enrichment of COPI-coated vesicles in both stages, this suggests the importance to P. knowlesi biology of clathrin-mediated endocytosis. P. knowlesi ribosomes and translation were also differentially enriched in the late ring stage. With expression of a variety of heat shock proteins, these results suggest production of folded parasite proteins is increasing by the late ring stage. M. mulatta endocytosis was differentially enriched in the late ring stage, as were clathrin-coated vesicles and endocytic vesicles. This suggests that M. mulatta clathrin-based endocytosis, perhaps in infected reticulocytes rather than mature RBC, may be an important process in the late ring stage. Additional ring stage biology from enriched GO terms includes M. mulatta proteasomes, protein folding and the chaperonin-containing T complex, actin and cortical actin cytoskeletons. P knowlesi biology also includes proteasomes, as well as nucleosomes, antioxidant activity, a variety of transport processes, glycolysis, vacuoles and protein folding. Mature RBCs have lost internal organelles, suggesting infection here may involve immature reticulocytes still retaining organelles. P. knowlesi parasite proteasomes and translational machinery may be ring stage drug targets for known selective inhibitors of these processes in other Plasmodium species. To our knowledge this is the first examination of more than one timepoint within the ring stage. Our results expand knowledge of both host and parasite proteins, pathways and organelles underlying P. knowlesi ring stage biology.
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Affiliation(s)
- D C Anderson
- Biosciences Division, SRI International, Harrisonburg, VA 22802, USA.
| | - Mariko S Peterson
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA
| | - Stacey A Lapp
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA
| | - Mary R Galinski
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
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2
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Groomes PV, Paul AS, Duraisingh MT. Inhibition of malaria and babesiosis parasites by putative red blood cell targeting small molecules. Front Cell Infect Microbiol 2024; 14:1304839. [PMID: 38572319 PMCID: PMC10988762 DOI: 10.3389/fcimb.2024.1304839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 02/15/2024] [Indexed: 04/05/2024] Open
Abstract
Background Chemotherapies for malaria and babesiosis frequently succumb to the emergence of pathogen-related drug-resistance. Host-targeted therapies are thought to be less susceptible to resistance but are seldom considered for treatment of these diseases. Methods Our overall objective was to systematically assess small molecules for host cell-targeting activity to restrict proliferation of intracellular parasites. We carried out a literature survey to identify small molecules annotated for host factors implicated in Plasmodium falciparum infection. Alongside P. falciparum, we implemented in vitro parasite susceptibility assays also in the zoonotic parasite Plasmodium knowlesi and the veterinary parasite Babesia divergens. We additionally carried out assays to test directly for action on RBCs apart from the parasites. To distinguish specific host-targeting antiparasitic activity from erythrotoxicity, we measured phosphatidylserine exposure and hemolysis stimulated by small molecules in uninfected RBCs. Results We identified diverse RBC target-annotated inhibitors with Plasmodium-specific, Babesia-specific, and broad-spectrum antiparasitic activity. The anticancer MEK-targeting drug trametinib is shown here to act with submicromolar activity to block proliferation of Plasmodium spp. in RBCs. Some inhibitors exhibit antimalarial activity with transient exposure to RBCs prior to infection with parasites, providing evidence for host-targeting activity distinct from direct inhibition of the parasite. Conclusions We report here characterization of small molecules for antiproliferative and host cell-targeting activity for malaria and babesiosis parasites. This resource is relevant for assessment of physiological RBC-parasite interactions and may inform drug development and repurposing efforts.
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Affiliation(s)
| | | | - Manoj T. Duraisingh
- Department of Immunology & Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, United States
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Peters MA, King AA, Wale N. Red blood cell dynamics during malaria infection violate the assumptions of mathematical models of infection dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.575051. [PMID: 38260611 PMCID: PMC10802624 DOI: 10.1101/2024.01.10.575051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
For decades, mathematical models have been used to understand the course and outcome of malaria infections (i.e., infection dynamics) and the evolutionary dynamics of the parasites that cause them. A key conclusion of these models is that red blood cell (RBC) availability is a fundamental driver of infection dynamics and parasite trait evolution. The extent to which this conclusion holds will in part depend on model assumptions about the host-mediated processes that regulate RBC availability i.e., removal of uninfected RBCs and supply of RBCs. Diverse mathematical functions have been used to describe host-mediated RBC supply and clearance, but it remains unclear whether they adequately capture the dynamics of RBC supply and clearance during infection. Here, we use a unique dataset, comprising time-series measurements of erythrocyte (i.e., mature RBC) and reticulocyte (i.e., newly supplied RBC) densities during Plasmodium chabaudi malaria infection, and a quantitative data-transformation scheme to elucidate whether RBC dynamics conform to common model assumptions. We found that RBC clearance and supply are not well described by mathematical functions commonly used to model these processes. Furthermore, the temporal dynamics of both processes vary with parasite growth rate in a manner again not captured by existing models. Together, these finding suggest that new model formulations are required if we are to explain and ultimately predict the within-host population dynamics and evolution of malaria parasites.
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Affiliation(s)
- Madeline A.E. Peters
- Department of Microbiology, Genetics & Immunology, Michigan State University, East Lansing, Michigan, USA
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Aaron A. King
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
- Center for the Study of Complex Systems, University of Michigan, Ann Arbor, Michigan, USA
- Department of Mathematics, University of Michigan, Ann Arbor, Michigan, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
| | - Nina Wale
- Department of Microbiology, Genetics & Immunology, Michigan State University, East Lansing, Michigan, USA
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, USA
- Program in Ecology, Evolution and Behavior, Michigan State University, East Lansing, Michigan, USA
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Lee SK, Nguyen TK, Mohring F, Han JH, Firdaus ER, Na SH, Park WS, Moon RW, Han ET. Merozoite surface protein 1 paralog is involved in the human erythrocyte invasion of a zoonotic malaria, Plasmodium knowlesi. Front Cell Infect Microbiol 2023; 13:1314533. [PMID: 38111629 PMCID: PMC10726050 DOI: 10.3389/fcimb.2023.1314533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 11/15/2023] [Indexed: 12/20/2023] Open
Abstract
The zoonotic malaria parasite Plasmodium knowlesi is an important public health concern in Southeast Asia. Invasion of host erythrocytes is essential for parasite growth, and thus, understanding the repertoire of parasite proteins that enable this process is vital for identifying vaccine candidates and how some species are able to cause zoonotic infection. Merozoite surface protein 1 (MSP1) is found in all malaria parasite species and is perhaps the most well-studied as a potential vaccine candidate. While MSP1 is encoded by a single gene in P. falciparum, all other human infective species (P. vivax, P. knowlesi, P. ovale, and P. malariae) additionally encode a divergent paralogue known as MSP1P, and little is known about its role or potential functional redundancy with MSP1. We, therefore, studied the function of P. knowlesi merozoite surface protein 1 paralog (PkMSP1P), using both recombinant protein and CRISPR-Cas9 genome editing. The recombinant 19-kDa C-terminus of PkMSP1P (PkMSP1P-19) was shown to bind specifically to human reticulocytes. However, immunoblotting data suggested that PkMSP1P-19-induced antibodies can recognize PkMSP1-19 and vice versa, confounding our ability to separate the properties of these two proteins. Targeted disruption of the pkmsp1p gene profoundly impacts parasite growth, demonstrating for the first time that PkMSP1P is important in in vitro growth of P. knowlesi and likely plays a distinct role from PkMSP1. Importantly, the MSP1P KO also enabled functional characterization of the PkMSP1P-19 antibodies, revealing clear immune cross-reactivity between the two paralogues, highlighting the vital importance of genetic studies in contextualizing recombinant protein studies.
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Affiliation(s)
- Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Tuyet Kha Nguyen
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Franziska Mohring
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Egy Rahman Firdaus
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Sung-Hun Na
- Department of Obstetrics and Gynecology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Won-Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Robert W. Moon
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
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Shittu O, Oniya MO, Olusi TA. Circulating platelets and malaria severity: two sides of the same coin among inhabitants of a tropical savannah region, Nigeria. Parasitol Res 2023; 122:2503-2511. [PMID: 37658925 DOI: 10.1007/s00436-023-07949-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/18/2023] [Indexed: 09/05/2023]
Abstract
Changes in circulating platelets during different grades of malaria are of major concerns, and its etiology is poorly understood. We appraised and evaluated the role of circulating platelets in the determination of the severity of malaria among a cohort of outpatients living in Ilorin, Nigeria. A hospital-based case-control study of outpatients visiting public health facilities within the locality voluntarily enrolled for this study. Blood samples from 1162 malaise patients were screened using routine microscopy for Plasmodium parasite species identification, and their respective circulating platelet levels were determined. Seven hundred and seventy-five individuals (775, 66.7%, p<0.001) were malaria-positive. Samples from 387 (33.3%) uninfected healthy individuals were used as controls. Individuals with uncomplicated malaria (UCM) and complicated malaria (CM) across age group were notable (p<0.05). Children ≤5 years had the highest number of individuals with CM (103, 45.2%) with a relative risk ratio of 4.005 (95% CI: 2.964-5.413). UCM (471, 40.5%) occurred more than CM (304, 26.2%) (p>0.05) across the groups. The geometric mean, 95% CI, median, and IQR of populations with malaria thrombocytopenia were higher (181, 110.94±2.207, 106.59-115.30, 118.00, and 39.00) than thrombocytosis (78, 624.64±13.131, 598.49-650.79, 623.00, and 208). Seemingly, health controls recorded insignificant morbidity with respect to platelet counts. High P. falciparum parasitemia is inversely correlated with platelet count, and its' morbidity is associated with the manifestation of several malaria pathogenesis. Thrombocytopenia is a silent pathophysiological attribute that can trigger other cofactors during severe malaria disease. Although further studies are pertinent in order to specifically clarify its relevance to clinical disease spectrum.
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Affiliation(s)
- Olalere Shittu
- Parasitology and Public Health Unit, Department of Biology, Federal University of Technology, Akure, Nigeria.
- Parasitology Unit, Department of Zoology, University of Ilorin, Ilorin, Nigeria.
| | - Mobolanle Oladipo Oniya
- Parasitology and Public Health Unit, Department of Biology, Federal University of Technology, Akure, Nigeria
| | - Titus Adeniyi Olusi
- Parasitology and Public Health Unit, Department of Biology, Federal University of Technology, Akure, Nigeria
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Jajosky RP, Wu SC, Jajosky PG, Stowell SR. Plasmodium knowlesi ( Pk) Malaria: A Review & Proposal of Therapeutically Rational Exchange (T-REX) of Pk-Resistant Red Blood Cells. Trop Med Infect Dis 2023; 8:478. [PMID: 37888606 PMCID: PMC10610852 DOI: 10.3390/tropicalmed8100478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/09/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
Plasmodium knowlesi (Pk) causes zoonotic malaria and is known as the "fifth human malaria parasite". Pk malaria is an emerging threat because infections are increasing and can be fatal. While most infections are in Southeast Asia (SEA), especially Malaysia, travelers frequently visit this region and can present with Pk malaria around the world. So, clinicians need to know (1) patients who present with fever after recent travel to SEA might be infected with Pk and (2) Pk is often misdiagnosed as P. malariae (which typically causes less severe malaria). Here we review the history, pathophysiology, clinical features, diagnosis, and treatment of Pk malaria. Severe disease is most common in adults. Signs and symptoms can include fever, abdominal pain, jaundice, acute kidney injury, acute respiratory distress syndrome, hyponatremia, hyperparasitemia, and thrombocytopenia. Dengue is one of the diseases to be considered in the differential. Regarding pathophysiologic mechanisms, when Pk parasites invade mature red blood cells (RBCs, i.e., normocytes) and reticulocytes, changes in the red blood cell (RBC) surface can result in life-threatening cytoadherence, sequestration, and reduced RBC deformability. Since molecular mechanisms involving the erythrocytic stage are responsible for onset of severe disease and lethal outcomes, it is biologically plausible that manual exchange transfusion (ET) or automated RBC exchange (RBCX) could be highly beneficial by replacing "sticky" parasitized RBCs with uninfected, deformable, healthy donor RBCs. Here we suggest use of special Pk-resistant donor RBCs to optimize adjunctive manual ET/RBCX for malaria. "Therapeutically-rational exchange transfusion" (T-REX) is proposed in which Pk-resistant RBCs are transfused (instead of disease-promoting RBCs). Because expression of the Duffy antigen on the surface of human RBCs is essential for parasite invasion, T-REX of Duffy-negative RBCs-also known as Fy(a-b-) RBCs-could replace the majority of the patient's circulating normocytes with Pk invasion-resistant RBCs (in a single procedure lasting about 2 h). When sequestered or non-sequestered iRBCs rupture-in a 24 h Pk asexual life cycle-the released merozoites cannot invade Fy(a-b-) RBCs. When Fy(a-b-) RBC units are scarce (e.g., in Malaysia), clinicians can consider the risks and benefits of transfusing plausibly Pk-resistant RBCs, such as glucose-6-phosphate dehydrogenase deficient (G6PDd) RBCs and Southeast Asian ovalocytes (SAO). Patients typically require a very short recovery time (<1 h) after the procedure. Fy(a-b-) RBCs should have a normal lifespan, while SAO and G6PDd RBCs may have mildly reduced half-lives. Because SAO and G6PDd RBCs come from screened blood donors who are healthy and not anemic, these RBCs have a low-risk for hemolysis and do not need to be removed after the patient recovers from malaria. T-REX could be especially useful if (1) antimalarial medications are not readily available, (2) patients are likely to progress to severe disease, or (3) drug-resistant strains emerge. In conclusion, T-REX is a proposed optimization of manual ET/RBCX that has not yet been utilized but can be considered by physicians to treat Pk malaria patients.
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Affiliation(s)
- Ryan Philip Jajosky
- Joint Program in Transfusion Medicine, Brigham and Women’s Hospital, Harvard Medical School, 630E New Research Building, 77 Avenue Louis Pasteur, Boston, MA 02115, USA; (S.-C.W.)
- Biconcavity Inc., Lilburn, GA 30047, USA
| | - Shang-Chuen Wu
- Joint Program in Transfusion Medicine, Brigham and Women’s Hospital, Harvard Medical School, 630E New Research Building, 77 Avenue Louis Pasteur, Boston, MA 02115, USA; (S.-C.W.)
| | | | - Sean R. Stowell
- Joint Program in Transfusion Medicine, Brigham and Women’s Hospital, Harvard Medical School, 630E New Research Building, 77 Avenue Louis Pasteur, Boston, MA 02115, USA; (S.-C.W.)
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7
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Dash R, Skillman KM, Pereira L, Mascarenhas A, Dass S, Walke J, Almeida A, Fernandes M, Gomes E, White J, Chery-Karschney L, Khandeparkar A, Rathod PK, Duraisingh MT, Kanjee U. Development of a Plasmodium vivax biobank for functional ex vivo assays. Malar J 2023; 22:250. [PMID: 37653486 PMCID: PMC10470152 DOI: 10.1186/s12936-023-04668-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/07/2023] [Indexed: 09/02/2023] Open
Abstract
BACKGROUND Plasmodium vivax is the second most prevalent cause of malaria yet remains challenging to study due to the lack of a continuous in vitro culture system, highlighting the need to establish a biobank of clinical isolates with multiple freezes per sample for use in functional assays. Different methods for cryopreserving parasite isolates were compared and subsequently the most promising one was validated. Enrichment of early- and late-stage parasites and parasite maturation were quantified to facilitate assay planning. METHODS In order to compare cryopreservation protocols, nine clinical P. vivax isolates were frozen with four glycerolyte-based mixtures. Parasite recovery post thaw, post KCl-Percoll enrichment and in short-term in vitro culture was measured via slide microscopy. Enrichment of late-stage parasites by magnetic activated cell sorting (MACS) was measured. Short and long-term storage of parasites at either - 80 °C or liquid nitrogen were also compared. RESULTS Of the four cryopreservation mixtures, one mixture (glycerolyte:serum:RBC at a 2.5:1.5:1 ratio) resulted in improved parasite recovery and statistically significant (P < 0.05) enhancement in parasite survival in short-term in vitro culture. A parasite biobank was subsequently generated using this protocol resulting in a collection of 106 clinical isolates, each with 8 vials. The quality of the biobank was validated by measuring several factors from 47 thaws: the average reduction in parasitaemia post-thaw (25.3%); the average fold enrichment post KCl-Percoll (6.65-fold); and the average percent recovery of parasites (22.0%, measured from 30 isolates). During short-term in vitro culture, robust maturation of ring stage parasites to later stages (> 20% trophozoites, schizonts and gametocytes) was observed in 60.0% of isolates by 48 h. Enrichment of mature parasite stages via MACS showed good reproducibility, with an average of 30.0% post-MACS parasitaemia and an average of 5.30 × 105 parasites/vial. Finally, the effect of storage temperature was tested, and no large impacts from short-term (7 days) or long-term (7-10 years) storage at - 80 °C on parasite recovery, enrichment or viability was observed. CONCLUSIONS Here, an optimized freezing method for P. vivax clinical isolates is demonstrated as a template for the generation and validation of a parasite biobank for use in functional assays.
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Affiliation(s)
- Rashmi Dash
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Kristen M Skillman
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Ligia Pereira
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Anjali Mascarenhas
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Sheena Dass
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Jayashri Walke
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Anvily Almeida
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Mezia Fernandes
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Edwin Gomes
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
| | - John White
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Laura Chery-Karschney
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | | | - Pradipsinh K Rathod
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA.
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8
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Han Z, Zheng Y, Shi Y, Chen F, Wu C, Wang L, Lu S, Li D, Guan X, He L, Zhao J. Transcriptional variation in Babesia gibsoni (Wuhan isolate) between in vivo and in vitro cultures in blood stage. Parasit Vectors 2023; 16:268. [PMID: 37550766 PMCID: PMC10408140 DOI: 10.1186/s13071-023-05869-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/04/2023] [Indexed: 08/09/2023] Open
Abstract
BACKGROUND Babesia gibsoni, the causative agent of canine babesiosis, belongs to the phylum Apicomplexa. The development of in vitro culture technology has driven research progress in various kinds of omics studies, including transcriptomic analysis of Plasmodium spp. between in vitro and in vivo environments, which has prompted the observation of diagnostic antigens and vaccine development. Nevertheless, no information on Babesia spp. could be obtained in this respect, which greatly hinders the further understanding of parasite growth and development in the blood stage. METHODS In this study, considerable changes in the morphology and infectivity of continuous in vitro cultured B. gibsoni (Wuhan isolate) were observed compared to in vivo parasites. Based on these changes, B. gibsoni (Wuhan isolate) was collected from both in vivo and in vitro cultures, followed by total RNA extraction and Illumina transcriptome sequencing. The acquired differentially expressed genes (DEGs) were validated using qRT-PCR, and then functionally annotated through several databases. The gene with the greatest upregulation after in vitro culture was cloned from the genome of B. gibsoni (Wuhan isolate) and characterized by western blotting and indirect immunofluorescence assay for detecting the native form and cellular localization. RESULTS Through laboratory cultivation, multiple forms of parasites were observed, and the infectivity of in vitro cultured parasites in dogs was found to be lower. Based on these changes, Illumina transcriptome sequencing was conducted, showing that 377 unigenes were upregulated and 334 unigenes were downregulated. Notably, an AP2 transcription factor family, essential for all developmental stages of parasites, was screened, and the transcriptional changes in these family members were tested. Thus, the novel AP2 transcription factor gene (BgAP2-M) with the highest upregulated expression after in vitro adaptation was selected. This gene comprises an open reading frame (ORF) of 1989 base pairs encoding a full-length protein of 662 amino acids. BgAP2-M contains one AP2 domain and one ACDC conserved domain, which may be involved in the nuclear biology of parasites. The prepared polyclonal antibodies against the BgAP2-M peptides further detected a native size of ~ 73 kDa and were localized to the nuclei of B. gibsoni. CONCLUSION This study presents a thorough transcriptome analysis of B. gibsoni in vivo and in vitro for the first time, contributing to a detailed understanding of the effects of environmental changes on the growth and development of parasites in the blood stage. Moreover, it also provides a deeper investigation for the different members of the ApiAP2 transcription factor family as various life stage regulators in Babesia spp.
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Affiliation(s)
- Zhen Han
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Yaxin Zheng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Yu Shi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Fangwei Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Chenglong Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Lingna Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Shiyu Lu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Dongfang Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Xingai Guan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Lan He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, 430070, Hubei, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China.
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, 430070, Hubei, China.
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9
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Mewara A, Sreenivasan P, Khurana S. Primate malaria of human importance. Trop Parasitol 2023; 13:73-83. [PMID: 37860614 PMCID: PMC10583777 DOI: 10.4103/tp.tp_79_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 06/10/2023] [Indexed: 10/21/2023] Open
Abstract
Nonhuman primate (NHP) malaria poses a major threat to the malaria control programs. The last two decades have witnessed a paradigm shift in our understanding of the malaria caused by species other than the traditionally known human Plasmodium species - Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale. The emergence of the malaria parasite of long-tailed macaque monkeys, Plasmodium knowlesi, as the fifth malaria species of humans has made the scientific community consider the risk of other zoonotic malaria, such as Plasmodium cynomolgi, Plasmodium simium, Plasmodium inui, and others, to humans. The development of knowledge about P. knowlesi as a pathogen which was earlier only known to experimentally cause malaria in humans and rarely cause natural infection, toward its acknowledgment as a significant cause of human malaria and a threat of malaria control programs has been made possible by the use of advanced molecular techniques such as polymerase chain reaction and gene sequencing. This review explores the various aspects of NHP malaria, and the association of various factors with their emergence and potential to cause human malaria which are important to understand to be able to control these emerging infections.
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Affiliation(s)
- Abhishek Mewara
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Priya Sreenivasan
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sumeeta Khurana
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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10
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Dash R, Skillman KM, Pereira L, Mascarenhas A, Dass S, Walke J, Almeida A, Fernandes M, Gomes E, White J, Chery-Karschney L, Khandeparkar A, Rathod PK, Duraisingh MT, Kanjee U. Development of a Plasmodium vivax biobank for functional ex vivo assays. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533128. [PMID: 36993272 PMCID: PMC10055260 DOI: 10.1101/2023.03.17.533128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Background Plasmodium vivax is the second most prevalent cause of malaria yet remains challenging to study due to the lack of a continuous in vitro culture system, highlighting the need to establish a biobank of clinical isolates with multiple freezes per sample for use in functional assays. Different methods for cryopreserving parasite isolates were compared and subsequently the most promising one was validated. Enrichment of early- and late-stage parasites and parasite maturation were quantified to facilitate assay planning. Methods In order to compare cryopreservation protocols, nine clinical P. vivax isolates were frozen with four glycerolyte-based mixtures. Parasite recovery post thaw, post KCl-Percoll enrichment and in short-term in vitro culture was measured via slide microscopy. Enrichment of late-stage parasites by magnetic activated cell sorting (MACS) was measured. Short and long-term storage of parasites at either -80°C or liquid nitrogen were also compared. Results Of the four cryopreservation mixtures, one mixture (glycerolyte:serum:RBC at a 2.5:1.5:1 ratio) resulted in improved parasite recovery and statistically significant (P<0.05) enhancement in parasite survival in short-term in vitro culture. A parasite biobank was subsequently generated using this protocol resulting in a collection with 106 clinical isolates, each with 8 vials. The quality of the biobank was validated by measuring several factors from 47 thaws: the average reduction in parasitemia post-thaw (25.3%); the average fold enrichment post KCl-Percoll (6.65-fold); and the average percent recovery of parasites (22.0%, measured from 30 isolates). During short-term in vitro culture, robust maturation of ring stage parasites to later stages (>20% trophozoites, schizonts and gametocytes) was observed in 60.0% of isolates by 48 hours. Enrichment of mature parasite stages via MACS showed good reproducibility, with an average 30.0% post-MACS parasitemia and an average 5.30 × 10 5 parasites/vial. Finally, the effect of storage temperature was tested, and no large impacts from short-term (7 day) or long term (7 - 10 year) storage at -80°C on parasite recovery, enrichment or viability was observed. Conclusions Here, an optimized freezing method for P. vivax clinical isolates is demonstrated as a template for the generation and validation of a parasite biobank for use in functional assays.
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11
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Defining species-specific and conserved interactions of apical membrane protein 1 during erythrocyte invasion in malaria to inform multi-species vaccines. Cell Mol Life Sci 2023; 80:74. [PMID: 36847896 PMCID: PMC9969379 DOI: 10.1007/s00018-023-04712-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/17/2023] [Accepted: 01/30/2023] [Indexed: 03/01/2023]
Abstract
Plasmodium falciparum and P. vivax are the major causes of human malaria, and P. knowlesi is an important additional cause in SE Asia. Binding of apical membrane antigen 1 (AMA1) to rhoptry neck protein 2 (RON2) was thought to be essential for merozoite invasion of erythrocytes by Plasmodium spp. Our findings reveal that P. falciparum and P. vivax have diverged and show species-specific binding of AMA1 to RON2, determined by a β-hairpin loop in RON2 and specific residues in AMA1 Loop1E. In contrast, cross-species binding of AMA1 to RON2 is retained between P. vivax and P. knowlesi. Mutation of specific amino acids in AMA1 Loop1E in P. falciparum or P. vivax ablated RON2 binding without impacting erythrocyte invasion. This indicates that the AMA1-RON2-loop interaction is not essential for invasion and additional AMA1 interactions are involved. Mutations in AMA1 that disrupt RON2 binding also enable escape of invasion inhibitory antibodies. Therefore, vaccines and therapeutics will need to be broader than targeting only the AMA1-RON2 interaction. Antibodies targeting AMA1 domain 3 had greater invasion-inhibitory activity when RON2-loop binding was ablated, suggesting this domain is a promising additional target for vaccine development. Targeting multiple AMA1 interactions involved in invasion may enable vaccines that generate more potent inhibitory antibodies and address the capacity for immune evasion. Findings on specific residues for invasion function and species divergence and conservation can inform novel vaccines and therapeutics against malaria caused by three species, including the potential for cross-species vaccines.
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12
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Burns AL, Sleebs BE, Gancheva M, McLean KT, Siddiqui G, Venter H, Beeson JG, O’Handley R, Creek DJ, Ma S, Frölich S, Goodman CD, McFadden GI, Wilson DW. Targeting malaria parasites with novel derivatives of azithromycin. Front Cell Infect Microbiol 2022; 12:1063407. [PMID: 36530422 PMCID: PMC9748569 DOI: 10.3389/fcimb.2022.1063407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/09/2022] [Indexed: 12/02/2022] Open
Abstract
Introduction The spread of artemisinin resistant Plasmodium falciparum parasites is of global concern and highlights the need to identify new antimalarials for future treatments. Azithromycin, a macrolide antibiotic used clinically against malaria, kills parasites via two mechanisms: 'delayed death' by inhibiting the bacterium-like ribosomes of the apicoplast, and 'quick-killing' that kills rapidly across the entire blood stage development. Methods Here, 22 azithromycin analogues were explored for delayed death and quick-killing activities against P. falciparum (the most virulent human malaria) and P. knowlesi (a monkey parasite that frequently infects humans). Results Seventeen analogues showed improved quick-killing against both Plasmodium species, with up to 38 to 20-fold higher potency over azithromycin after less than 48 or 28 hours of treatment for P. falciparum and P. knowlesi, respectively. Quick-killing analogues maintained activity throughout the blood stage lifecycle, including ring stages of P. falciparum parasites (<12 hrs treatment) and were >5-fold more selective against P. falciparum than human cells. Isopentenyl pyrophosphate supplemented parasites that lacked an apicoplast were equally sensitive to quick-killing analogues, confirming that the quick killing activity of these drugs was not directed at the apicoplast. Further, activity against the related apicoplast containing parasite Toxoplasma gondii and the gram-positive bacterium Streptococcus pneumoniae did not show improvement over azithromycin, highlighting the specific improvement in antimalarial quick-killing activity. Metabolomic profiling of parasites subjected to the most potent compound showed a build-up of non-haemoglobin derived peptides that was similar to chloroquine, while also exhibiting accumulation of haemoglobin-derived peptides that was absent for chloroquine treatment. Discussion The azithromycin analogues characterised in this study expand the structural diversity over previously reported quick-killing compounds and provide new starting points to develop azithromycin analogues with quick-killing antimalarial activity.
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Affiliation(s)
- Amy L. Burns
- Research Centre for Infectious Diseases, School of Biological Sciences, the University of Adelaide, Adelaide, SA, Australia,School of Science and Technology, the University of New England, Armidale, NSW, Australia
| | - Brad E. Sleebs
- ACRF Chemical Biology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Maria Gancheva
- Research Centre for Infectious Diseases, School of Biological Sciences, the University of Adelaide, Adelaide, SA, Australia
| | - Kimberley T. McLean
- Research Centre for Infectious Diseases, School of Biological Sciences, the University of Adelaide, Adelaide, SA, Australia
| | - Ghizal Siddiqui
- Drug Delivery Disposition and Dynamics, Monash University, Parkville, VIC, Australia
| | - Henrietta Venter
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - James G. Beeson
- Healthy Mothers, Healthy Babies Program, Burnet Institute, Melbourne, VIC, Australia,Department of Medicine, University of Melbourne, Parkville, VIC, Australia,Central Clinical School, Monash University, Melbourne, Vic, Australia,Department of Microbiology, Monash University, Melbourne, Vic, Australia
| | - Ryan O’Handley
- School of Animal and Veterinary Science, University of Adelaide, Adelaide, SA, Australia,Australian Centre for Antimicrobial Resistance Ecology, The University of Adelaide, Adelaide, SA, Australia
| | - Darren J. Creek
- Drug Delivery Disposition and Dynamics, Monash University, Parkville, VIC, Australia
| | - Shutao Ma
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Sonja Frölich
- Research Centre for Infectious Diseases, School of Biological Sciences, the University of Adelaide, Adelaide, SA, Australia
| | | | | | - Danny W. Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, the University of Adelaide, Adelaide, SA, Australia,Healthy Mothers, Healthy Babies Program, Burnet Institute, Melbourne, VIC, Australia,Australian Centre for Antimicrobial Resistance Ecology, The University of Adelaide, Adelaide, SA, Australia,*Correspondence: Danny W. Wilson,
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13
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Satchwell TJ. Generation of red blood cells from stem cells: Achievements, opportunities and perspectives for malaria research. Front Cell Infect Microbiol 2022; 12:1039520. [PMID: 36452302 PMCID: PMC9702814 DOI: 10.3389/fcimb.2022.1039520] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/21/2022] [Indexed: 06/22/2024] Open
Abstract
Parasites of the genus Plasmodium that cause malaria survive within humans by invasion of, and proliferation within, the most abundant cell type in the body, the red blood cell. As obligate, intracellular parasites, interactions between parasite and host red blood cell components are crucial to multiple aspects of the blood stage malaria parasite lifecycle. The requirement for, and involvement of, an array of red blood cell proteins in parasite invasion and intracellular development is well established. Nevertheless, detailed mechanistic understanding of host cell protein contributions to these processes are hampered by the genetic intractability of the anucleate red blood cell. The advent of stem cell technology and more specifically development of methods that recapitulate in vitro the process of red blood cell development known as erythropoiesis has enabled the generation of erythroid cell stages previously inaccessible in large numbers for malaria studies. What is more, the capacity for genetic manipulation of nucleated erythroid precursors that can be differentiated to generate modified red blood cells has opened new horizons for malaria research. This review summarises current methodologies that harness in vitro erythroid differentiation of stem cells for generation of cells that are susceptible to malaria parasite invasion; discusses existing and emerging approaches to generate novel red blood cell phenotypes and explores the exciting potential of in vitro derived red blood cells for improved understanding the broad role of host red blood cell proteins in malaria pathogenesis.
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14
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Leong YW, Russell B, Malleret B, Rénia L. Erythrocyte tropism of malarial parasites: The reticulocyte appeal. Front Microbiol 2022; 13:1022828. [PMID: 36386653 PMCID: PMC9643692 DOI: 10.3389/fmicb.2022.1022828] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/07/2022] [Indexed: 10/28/2023] Open
Abstract
Erythrocytes are formed from the enucleation of erythroblasts in the bone marrow, and as erythrocytes develop from immature reticulocytes into mature normocytes, they undergo extensive cellular changes through their passage in the blood. During the blood stage of the malarial parasite life cycle, the parasite sense and invade susceptible erythrocytes. However, different parasite species display varying erythrocyte tropisms (i.e., preference for either reticulocytes or normocytes). In this review, we explore the erythrocyte tropism of malarial parasites, especially their predilection to invade reticulocytes, as shown from recent studies. We also discuss possible mechanisms mediating erythrocyte tropism and the implications of specific tropisms to disease pathophysiology. Understanding these allows better insight into the role of reticulocytes in malaria and provides opportunities for targeted interventions.
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Affiliation(s)
- Yew Wai Leong
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, Singapore, Singapore
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Benoit Malleret
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore, Singapore
- Department of Microbiology and Immunology, Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Laurent Rénia
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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15
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Oke CE, Ingham VA, Walling CA, Reece SE. Vector control: agents of selection on malaria parasites? Trends Parasitol 2022; 38:890-903. [PMID: 35981937 DOI: 10.1016/j.pt.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/30/2022] [Accepted: 07/21/2022] [Indexed: 10/15/2022]
Abstract
Insect vectors are responsible for spreading many infectious diseases, yet interactions between pathogens/parasites and insect vectors remain poorly understood. Filling this knowledge gap matters because vectors are evolving in response to the deployment of vector control tools (VCTs). Yet, whilst the evolutionary responses of vectors to VCTs are being carefully monitored, the knock-on consequences for parasite evolution have been overlooked. By examining how mosquito responses to VCTs impact upon malaria parasite ecology, we derive a framework for predicting parasite responses. Understanding how VCTs affect the selection pressures imposed on parasites could help to mitigate against parasite evolution that leads to unfavourable epidemiological outcomes. Furthermore, anticipating parasite evolution will inform monitoring strategies for VCT programmes as well as uncovering novel VCT strategies.
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Affiliation(s)
- Catherine E Oke
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK.
| | - Victoria A Ingham
- Centre for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69210 Heidelberg, Germany
| | - Craig A Walling
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Sarah E Reece
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK; Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
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16
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Thiam LG, Mangou K, Ba A, Mbengue A, Bei AK. Leveraging genome editing to functionally evaluate Plasmodium diversity. Trends Parasitol 2022; 38:558-571. [PMID: 35469746 DOI: 10.1016/j.pt.2022.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 12/13/2022]
Abstract
The ambitious goal of malaria elimination requires an in-depth understanding of the parasite's biology to counter the growing threat of antimalarial resistance and immune evasion. Timely assessment of the functional impact of antigenic diversity in the early stages of vaccine development will be critical for achieving the goal of malaria control, elimination, and ultimately eradication. Recent advances in targeted genome editing enabled the functional validation of resistance-associated markers in Plasmodium falciparum, the deadliest malaria-causing pathogen and strain-specific immune neutralization. This review explores recent advances made in leveraging genome editing to aid the functional evaluation of Plasmodium diversity and highlights how these techniques can assist in prioritizing both therapeutic and vaccine candidates.
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Affiliation(s)
- Laty Gaye Thiam
- G4 - Malaria Experimental Genetic Approaches & Vaccines, Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal
| | - Khadidiatou Mangou
- G4 - Malaria Experimental Genetic Approaches & Vaccines, Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal
| | - Aboubacar Ba
- G4 - Malaria Experimental Genetic Approaches & Vaccines, Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal
| | - Alassane Mbengue
- G4 - Malaria Experimental Genetic Approaches & Vaccines, Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal
| | - Amy K Bei
- G4 - Malaria Experimental Genetic Approaches & Vaccines, Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06510, USA.
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17
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Lee WC, Cheong FW, Amir A, Lai MY, Tan JH, Phang WK, Shahari S, Lau YL. Plasmodium knowlesi: the game changer for malaria eradication. Malar J 2022; 21:140. [PMID: 35505339 PMCID: PMC9066973 DOI: 10.1186/s12936-022-04131-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/18/2022] [Indexed: 11/12/2022] Open
Abstract
Plasmodium knowlesi is a zoonotic malaria parasite that has gained increasing medical interest over the past two decades. This zoonotic parasitic infection is prevalent in Southeast Asia and causes many cases with fulminant pathology. Despite several biogeographical restrictions that limit its distribution, knowlesi malaria cases have been reported in different parts of the world due to travelling and tourism activities. Here, breakthroughs and key information generated from recent (over the past five years, but not limited to) studies conducted on P. knowlesi were reviewed, and the knowledge gap in various research aspects that need to be filled was discussed. Besides, challenges and strategies required to control and eradicate human malaria with this emerging and potentially fatal zoonosis were described.
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Affiliation(s)
- Wenn-Chyau Lee
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Fei Wen Cheong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Amirah Amir
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Meng Yee Lai
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Jia Hui Tan
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Wei Kit Phang
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Shahhaziq Shahari
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
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18
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Ruiz Cuenca P, Key S, Lindblade KA, Vythilingam I, Drakeley C, Fornace K. Is there evidence of sustained human-mosquito-human transmission of the zoonotic malaria Plasmodium knowlesi? A systematic literature review. Malar J 2022; 21:89. [PMID: 35300703 PMCID: PMC8929260 DOI: 10.1186/s12936-022-04110-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/27/2022] [Indexed: 12/03/2022] Open
Abstract
Background The zoonotic malaria parasite Plasmodium knowlesi has emerged across Southeast Asia and is now the main cause of malaria in humans in Malaysia. A critical priority for P. knowlesi surveillance and control is understanding whether transmission is entirely zoonotic or is also occurring through human-mosquito-human transmission. Methods A systematic literature review was performed to evaluate existing evidence which refutes or supports the occurrence of sustained human-mosquito-human transmission of P. knowlesi. Possible evidence categories and study types which would support or refute non-zoonotic transmission were identified and ranked. A literature search was conducted on Medline, EMBASE and Web of Science using a broad search strategy to identify any possible published literature. Results were synthesized using the Synthesis Without Meta-analysis (SWiM) framework, using vote counting to combine the evidence within specific categories. Results Of an initial 7,299 studies screened, 131 studies were included within this review: 87 studies of P. knowlesi prevalence in humans, 14 studies in non-human primates, 13 studies in mosquitoes, and 29 studies with direct evidence refuting or supporting non-zoonotic transmission. Overall, the evidence showed that human-mosquito-human transmission is biologically possible, but there is limited evidence of widespread occurrence in endemic areas. Specific areas of research were identified that require further attention, notably quantitative analyses of potential transmission dynamics, epidemiological and entomological surveys, and ecological studies into the sylvatic cycle of the disease. Conclusion There are key questions about P. knowlesi that remain within the areas of research that require more attention. These questions have significant implications for malaria elimination and eradication programs. This paper considers limited but varied research and provides a methodological framework for assessing the likelihood of different transmission patterns for emerging zoonotic diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04110-z.
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Affiliation(s)
- Pablo Ruiz Cuenca
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster University Medical School, Lancaster, UK. .,Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Stephanie Key
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Kim A Lindblade
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Kimberly Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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19
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van Schalkwyk DA, Moon RW, Duffey M, Leroy D, Sutherland CJ. Ex vivo susceptibility to new antimalarial agents differs among human-infecting Plasmodium species. Int J Parasitol Drugs Drug Resist 2021; 17:5-11. [PMID: 34315108 PMCID: PMC8327131 DOI: 10.1016/j.ijpddr.2021.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/19/2021] [Accepted: 07/21/2021] [Indexed: 11/16/2022]
Abstract
Several promising antimalarial drugs are currently being tested in human trials, such as artefenomel, cipargamin, ferroquine and ganaplacide. Many of these compounds were identified using high throughput screens against a single species of human malaria, Plasmodium falciparum, under the assumption that effectiveness against all malaria species will be similar, as has been observed for other antimalarial drugs. However, using our in vitro adapted line, we demonstrated recently that P. knowlesi is significantly less susceptible than P. falciparum to some new antimalarial drugs (e.g., cipargamin and DSM265), and more susceptible to others (e.g., ganaplacide). There is, therefore, an urgent need to determine the susceptibility profile of all human malaria species to the current generation of antimalarial compounds. We obtained ex vivo malaria samples from travellers returning to the United Kingdom and, using the [3H]hypoxanthine incorporation method, compared susceptibility to select established and experimental antimalarial agents among all major human infective Plasmodium species. We demonstrate that P. malariae and P. ovale spp. are significantly less susceptible than P. falciparum to cipargamin, DSM265 and AN13762, but are more susceptible to ganaplacide. Preliminary ex vivo data from single isolates of P. knowlesi and P. vivax demonstrate a similar profile. Our findings highlight the need to ensure cross species susceptibility profiles are determined early in the drug development pipeline. Our data can also be used to inform further drug development, and illustrate the utility of the P. knowlesi in vitro model as a scalable approach for predicting the drug susceptibility of non-falciparum malaria species in general.
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Affiliation(s)
- Donelly A van Schalkwyk
- Department of Infection Biology, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Robert W Moon
- Department of Infection Biology, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Maëlle Duffey
- Medicines for Malaria Venture, 20 rte de Pré Bois, Geneva, CH 1215, Switzerland
| | - Didier Leroy
- Medicines for Malaria Venture, 20 rte de Pré Bois, Geneva, CH 1215, Switzerland
| | - Colin J Sutherland
- Department of Infection Biology, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK; Department of Clinical Parasitology, Hospital for Tropical Diseases, Mortimer Market Centre, Capper Street, London, WC1E 6JB, UK
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20
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Abstract
Plasmodium malaria parasites use a unique substrate-dependent locomotion, termed gliding motility, to migrate through tissues and invade cells. Previously, it was thought that the small labile invasive stages that invade erythrocytes, merozoites, use this motility solely to penetrate target erythrocytes. Here we reveal that merozoites use gliding motility for translocation across host cells prior to invasion. This forms an important preinvasion step that is powered by a conserved actomyosin motor and is regulated by a complex signaling pathway. This work broadens our understanding of the role of gliding motility and invasion in the blood and will have a significant impact on our understanding of blood stage host–pathogen interactions and parasite biology, with implications for interventions targeting erythrocyte invasion. Plasmodium malaria parasites are obligate intracellular protozoans that use a unique form of locomotion, termed gliding motility, to move through host tissues and invade cells. The process is substrate dependent and powered by an actomyosin motor that drives the posterior translocation of extracellular adhesins which, in turn, propel the parasite forward. Gliding motility is essential for tissue translocation in the sporozoite and ookinete stages; however, the short-lived erythrocyte-invading merozoite stage has never been observed to undergo gliding movement. Here we show Plasmodium merozoites possess the ability to undergo gliding motility in vitro and that this mechanism is likely an important precursor step for successful parasite invasion. We demonstrate that two human infective species, Plasmodium falciparum and Plasmodium knowlesi, have distinct merozoite motility profiles which may reflect distinct invasion strategies. Additionally, we develop and validate a higher throughput assay to evaluate the effects of genetic and pharmacological perturbations on both the molecular motor and the complex signaling cascade that regulates motility in merozoites. The discovery of merozoite motility provides a model to study the glideosome and adds a dimension for work aiming to develop treatments targeting the blood stage invasion pathways.
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21
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Property activity refinement of 2-anilino 4-amino substituted quinazolines as antimalarials with fast acting asexual parasite activity. Bioorg Chem 2021; 117:105359. [PMID: 34689083 DOI: 10.1016/j.bioorg.2021.105359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 08/25/2021] [Accepted: 09/12/2021] [Indexed: 11/23/2022]
Abstract
Malaria is a devastating disease caused by Plasmodium parasites. Emerging resistance against current antimalarial therapeutics has engendered the need to develop antimalarials with novel structural classes. We recently described the identification and initial optimization of the 2-anilino quinazoline antimalarial class. Here, we refine the physicochemical properties of this antimalarial class with the aim to improve aqueous solubility and metabolism and to reduce adverse promiscuity. We show the physicochemical properties of this class are intricately balanced with asexual parasite activity and human cell cytotoxicity. Structural modifications we have implemented improved LipE, aqueous solubility and in vitro metabolism while preserving fast acting P. falciparum asexual stage activity. The lead compounds demonstrated equipotent activity against P. knowlesi parasites and were not predisposed to resistance mechanisms of clinically used antimalarials. The optimized compounds exhibited modest activity against early-stage gametocytes, but no activity against pre-erythrocytic liver parasites. Confoundingly, the refined physicochemical properties installed in the compounds did not engender improved oral efficacy in a P. berghei mouse model of malaria compared to earlier studies on the 2-anilino quinazoline class. This study provides the framework for further development of this antimalarial class.
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22
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Barber BE, Grigg MJ, Cooper DJ, van Schalkwyk DA, William T, Rajahram GS, Anstey NM. Clinical management of Plasmodium knowlesi malaria. ADVANCES IN PARASITOLOGY 2021; 113:45-76. [PMID: 34620385 DOI: 10.1016/bs.apar.2021.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The zoonotic parasite Plasmodium knowlesi has emerged as an important cause of human malaria in parts of Southeast Asia. The parasite is indistinguishable by microscopy from the more benign P. malariae, but can result in high parasitaemias with multiorgan failure, and deaths have been reported. Recognition of severe knowlesi malaria, and prompt initiation of effective therapy is therefore essential to prevent adverse outcomes. Here we review all studies reporting treatment of uncomplicated and severe knowlesi malaria. We report that although chloroquine is effective for the treatment of uncomplicated knowlesi malaria, artemisinin combination treatment is associated with faster parasite clearance times and lower rates of anaemia during follow-up, and should be considered the treatment of choice, particularly given the risk of administering chloroquine to drug-resistant P. vivax or P. falciparum misdiagnosed as P. knowlesi malaria in co-endemic areas. For severe knowlesi malaria, intravenous artesunate has been shown to be highly effective and associated with reduced case-fatality rates, and should be commenced without delay. Regular paracetamol may also be considered for patients with severe knowlesi malaria or for those with acute kidney injury, to attenuate the renal damage resulting from haemolysis-induced lipid peroxidation.
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Affiliation(s)
- Bridget E Barber
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia.
| | - Matthew J Grigg
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Daniel J Cooper
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Department of Medicine, University of Cambridge School of Medicine, Cambridge, United Kingdom
| | | | - Timothy William
- Gleneagles Medical Centre, Kota Kinabalu, Malaysia; Clinical Research Centre, Queen Elizabeth Hospital 1, Kota Kinabalu, Malaysia
| | - Giri S Rajahram
- Clinical Research Centre, Queen Elizabeth Hospital 1, Kota Kinabalu, Malaysia; Queen Elizabeth Hospital 2, Kota Kinabalu, Malaysia
| | - Nicholas M Anstey
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
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23
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Knowlesi malaria: Human risk factors, clinical spectrum, and pathophysiology. ADVANCES IN PARASITOLOGY 2021; 113:1-43. [PMID: 34620381 DOI: 10.1016/bs.apar.2021.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plasmodium knowlesi is endemic across Southeast Asia, and is the commonest cause of zoonotic malaria. The spectrum of clinical disease from P. knowlesi infection ranges from asymptomatic infection, through to severe malaria and death. Over 90% of clinical disease occurs in adults, mostly living in forest edge areas undergoing intensive land use change. With a 24-h asexual life cycle in humans, high parasite counts are possible, but most clinical cases of knowlesi malaria are uncomplicated with low parasitaemia. In co-endemic areas, median parasitaemia in knowlesi malaria is lower than that seen in vivax and falciparum malaria, suggesting a lower fever threshold. Severe malaria occurs in 6-9% of symptomatic adults. Manifestations of severe malaria from P. knowlesi are similar to those seen with falciparum malaria, with the notable absence of coma. Age, parasitaemia, cardiovascular comorbidities and delayed diagnosis are risk factors for severe disease and death, which are only seen in adults. Thrombocytopenia is near-universal in adults, likely related to platelet-red cell binding and clearance. Mechanisms underlying the microvascular sludging seen in fatal disease in non-natural primate hosts and the microvascular accumulation of parasites in fatal human disease are not clear. Marked reductions in deformability of both infected and uninfected red blood cells are associated with disease severity in both humans and other non-natural primate hosts, likely contributing to impaired microvascular perfusion and organ dysfunction. Endothelial activation, endothelial dysfunction, glycocalyx degradation and haemolysis are also associated with, and likely contribute to, severe disease and organ dysfunction, particularly acute kidney injury.
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24
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Molecular epidemiology and population genomics of Plasmodium knowlesi. ADVANCES IN PARASITOLOGY 2021; 113:191-223. [PMID: 34620383 DOI: 10.1016/bs.apar.2021.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular epidemiology has been central to uncovering P. knowlesi as an important cause of human malaria in Southeast Asia, and to understanding the complex nature of this zoonosis. Species-specific parasite detection and characterization of sequences were vital to show that P. knowlesi was distinct from the human parasite species that had been presumed to cause all malaria. With established sensitive and specific molecular detection tools, surveys subsequently indicated the distribution of P. knowlesi infections in humans, wild primate reservoir host species, and mosquito vector species. The importance of studying P. knowlesi genetic polymorphism was indicated initially by analysing a few nuclear gene loci as well as the mitochondrial genome, and subsequently by multi-locus microsatellite analyses and whole-genome sequencing. Different human infections generally have unrelated P. knowlesi genotypes, acquired from the diverse local parasite reservoirs in macaques. However, individual human infections are usually less genetically complex than those of wild macaques which experience more frequent superinfection with different P. knowlesi genotypes. Multi-locus analyses have revealed deep population subdivisions within P. knowlesi, which are structured both geographically and in relation to different macaque reservoir host species. Simplified genotypic discrimination assays now enable efficient large-scale surveillance of the sympatric P. knowlesi subpopulations within Malaysian Borneo. The whole-genome sequence analyses have also identified loci under recent positive natural selection in the P. knowlesi genome, with evidence that different loci are affected in different populations. These provide a foundation to understand recent adaptation of the zoonotic parasite populations, and to track and interpret future changes as they emerge.
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25
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Opi DH, Kurtovic L, Chan JA, Horton JL, Feng G, Beeson JG. Multi-functional antibody profiling for malaria vaccine development and evaluation. Expert Rev Vaccines 2021; 20:1257-1272. [PMID: 34530671 DOI: 10.1080/14760584.2021.1981864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION A vaccine would greatly accelerate current global efforts toward malaria elimination. While a partially efficacious vaccine has been achieved for Plasmodium falciparum, a major bottleneck in developing highly efficacious vaccines is a lack of reliable correlates of protection, and the limited application of assays that quantify functional immune responses to evaluate and down-select vaccine candidates in pre-clinical studies and clinical trials. AREAS COVERED In this review, we describe the important role of antibodies in immunity against malaria and detail the nature and functional activities of antibodies against the malaria-causing parasite. We highlight the growing understanding of antibody effector functions against malaria and in vitro assays to measure these functional antibody responses. We discuss the application of these assays to quantify antibody functions in vaccine development and evaluation. EXPERT OPINION It is becoming increasingly clear that multiple antibody effector functions are involved in immunity to malaria. Therefore, we propose that evaluating vaccine candidates needs to move beyond individual assays or measuring IgG magnitude alone. Instead, vaccine evaluation should incorporate the full breadth of antibody response types and harness a wider range of assays measuring functional antibody responses. We propose a 3-tier approach to implementing assays to inform vaccine evaluation.
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Affiliation(s)
- D Herbert Opi
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Liriye Kurtovic
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Jessica L Horton
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Gaoqian Feng
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - James G Beeson
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia.,Department of Microbiology, Monash University, Clayton, Australia
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26
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Hang JW, Tukijan F, Lee EQH, Abdeen SR, Aniweh Y, Malleret B. Zoonotic Malaria: Non- Laverania Plasmodium Biology and Invasion Mechanisms. Pathogens 2021; 10:889. [PMID: 34358039 PMCID: PMC8308728 DOI: 10.3390/pathogens10070889] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/09/2021] [Accepted: 07/09/2021] [Indexed: 12/27/2022] Open
Abstract
Malaria, which is caused by Plasmodium parasites through Anopheles mosquito transmission, remains one of the most life-threatening diseases affecting hundreds of millions of people worldwide every year. Plasmodium vivax, which accounts for the majority of cases of recurring malaria caused by the Plasmodium (non-Laverania) subgenus, is an ancient and continuing zoonosis originating from monkey hosts probably outside Africa. The emergence of other zoonotic malarias (P. knowlesi, P. cynomolgi, and P. simium) further highlights the seriousness of the disease. The severity of this epidemic disease is dependent on many factors, including the parasite characteristics, host-parasite interactions, and the pathology of the infection. Successful infection depends on the ability of the parasite to invade the host; however, little is known about the parasite invasion biology and mechanisms. The lack of this information adds to the challenges to malaria control and elimination, hence enhancing the potential for continuation of this zoonosis. Here, we review the literature describing the characteristics, distribution, and genome details of the parasites, as well as host specificity, host-parasite interactions, and parasite pathology. This information will provide the basis of a greater understanding of the epidemiology and pathogenesis of malaria to support future development of strategies for the control and prevention of this zoonotic infection.
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Affiliation(s)
- Jing-Wen Hang
- Immunology Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore 117545, Singapore; (J.W.H.); (F.T.); (E.Q.H.L.)
| | - Farhana Tukijan
- Immunology Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore 117545, Singapore; (J.W.H.); (F.T.); (E.Q.H.L.)
| | - Erica-Qian-Hui Lee
- Immunology Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore 117545, Singapore; (J.W.H.); (F.T.); (E.Q.H.L.)
| | - Shifana Raja Abdeen
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore 138648, Singapore;
| | - Yaw Aniweh
- West Africa Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Accra, Ghana;
| | - Benoit Malleret
- Immunology Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore 117545, Singapore; (J.W.H.); (F.T.); (E.Q.H.L.)
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore 138648, Singapore;
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27
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Ndegwa DN, Kundu P, Hostetler JB, Marin-Menendez A, Sanderson T, Mwikali K, Verzier LH, Coyle R, Adjalley S, Rayner JC. Using Plasmodium knowlesi as a model for screening Plasmodium vivax blood-stage malaria vaccine targets reveals new candidates. PLoS Pathog 2021; 17:e1008864. [PMID: 34197567 PMCID: PMC8279373 DOI: 10.1371/journal.ppat.1008864] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 07/14/2021] [Accepted: 06/01/2021] [Indexed: 11/18/2022] Open
Abstract
Plasmodium vivax is responsible for the majority of malaria cases outside Africa. Unlike P. falciparum, the P. vivax life-cycle includes a dormant liver stage, the hypnozoite, which can cause infection in the absence of mosquito transmission. An effective vaccine against P. vivax blood stages would limit symptoms and pathology from such recurrent infections, and therefore could play a critical role in the control of this species. Vaccine development in P. vivax, however, lags considerably behind P. falciparum, which has many identified targets with several having transitioned to Phase II testing. By contrast only one P. vivax blood-stage vaccine candidate based on the Duffy Binding Protein (PvDBP), has reached Phase Ia, in large part because the lack of a continuous in vitro culture system for P. vivax limits systematic screening of new candidates. We used the close phylogenetic relationship between P. vivax and P. knowlesi, for which an in vitro culture system in human erythrocytes exists, to test the scalability of systematic reverse vaccinology to identify and prioritise P. vivax blood-stage targets. A panel of P. vivax proteins predicted to function in erythrocyte invasion were expressed as full-length recombinant ectodomains in a mammalian expression system. Eight of these antigens were used to generate polyclonal antibodies, which were screened for their ability to recognize orthologous proteins in P. knowlesi. These antibodies were then tested for inhibition of growth and invasion of both wild type P. knowlesi and chimeric P. knowlesi lines modified using CRISPR/Cas9 to exchange P. knowlesi genes with their P. vivax orthologues. Candidates that induced antibodies that inhibited invasion to a similar level as PvDBP were identified, confirming the utility of P. knowlesi as a model for P. vivax vaccine development and prioritizing antigens for further follow up.
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Affiliation(s)
- Duncan N. Ndegwa
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Department of Biological Sciences, University of Embu, Embu, Kenya
| | - Prasun Kundu
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, United Kingdom
| | - Jessica B. Hostetler
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | | | - Theo Sanderson
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Kioko Mwikali
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Lisa H. Verzier
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Rachael Coyle
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Sophie Adjalley
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Julian C. Rayner
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, United Kingdom
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28
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Hocking SE, Divis PCS, Kadir KA, Singh B, Conway DJ. Population Genomic Structure and Recent Evolution of Plasmodium knowlesi, Peninsular Malaysia. Emerg Infect Dis 2021; 26:1749-1758. [PMID: 32687018 PMCID: PMC7392424 DOI: 10.3201/eid2608.190864] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Most malaria in Malaysia is caused by Plasmodium knowlesi parasites through zoonotic infection from macaque reservoir hosts. We obtained genome sequences from 28 clinical infections in Peninsular Malaysia to clarify the emerging parasite population structure and test for evidence of recent adaptation. The parasites all belonged to a major genetic population of P. knowlesi (cluster 3) with high genomewide divergence from populations occurring in Borneo (clusters 1 and 2). We also observed unexpected local genetic subdivision; most parasites belonged to 2 subpopulations sharing a high level of diversity except at particular genomic regions, the largest being a region of chromosome 12, which showed evidence of recent directional selection. Surprisingly, we observed a third subpopulation comprising P. knowlesi infections that were almost identical to each other throughout much of the genome, indicating separately maintained transmission and recent genetic isolation. Each subpopulation could evolve and present a broader health challenge in Asia.
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29
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Buyon LE, Elsworth B, Duraisingh MT. The molecular basis of antimalarial drug resistance in Plasmodium vivax. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2021; 16:23-37. [PMID: 33957488 PMCID: PMC8113647 DOI: 10.1016/j.ijpddr.2021.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/31/2021] [Accepted: 04/08/2021] [Indexed: 01/07/2023]
Abstract
Plasmodium vivax is the most geographically widespread cause of human malaria and is responsible for the majority of cases outside of the African continent. While great progress has been made towards eliminating human malaria, drug resistant parasite strains pose a threat towards continued progress. Resistance has arisen to multiple antimalarials in P. vivax, including to chloroquine, which is currently the first line therapy for P. vivax in most regions. Despite its importance, an understanding of the molecular mechanisms of drug resistance in this species remains elusive, in large part due to the complex biology of P. vivax and the lack of in vitro culture. In this review, we will cover the extent and challenges of measuring clinical and in vitro drug resistance in P. vivax. We will consider the roles of candidate drug resistance genes. We will highlight the development of molecular approaches for studying P. vivax biology that provide the opportunity to validate the role of putative drug resistance mutations as well as identify novel mechanisms of drug resistance in this understudied parasite. Validated molecular determinants and markers of drug resistance are essential for the rapid and cost-effective monitoring of drug resistance in P. vivax, and will be useful for optimizing drug regimens and for informing drug policy in control and elimination settings. Drug resistance is emerging in Plasmodium vivax, an important cause of malaria. The complex biology of P. vivax and the limited range of research tools make it difficult to identify drug resistance. The molecular mechanisms of drug resistance in P. vivax remain elusive. This review highlights the extent of drug resistance, the putative mechanisms of resistance and new technologies for the study of P. vivax drug resistance.
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Affiliation(s)
- Lucas E Buyon
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Brendan Elsworth
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA.
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30
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Brown AC, Guler JL. From Circulation to Cultivation: Plasmodium In Vivo versus In Vitro. Trends Parasitol 2020; 36:914-926. [DOI: 10.1016/j.pt.2020.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/17/2022]
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31
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Burns AL, Sleebs BE, Siddiqui G, De Paoli AE, Anderson D, Liffner B, Harvey R, Beeson JG, Creek DJ, Goodman CD, McFadden GI, Wilson DW. Retargeting azithromycin analogues to have dual-modality antimalarial activity. BMC Biol 2020; 18:133. [PMID: 32993629 PMCID: PMC7526119 DOI: 10.1186/s12915-020-00859-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Resistance to front-line antimalarials (artemisinin combination therapies) is spreading, and development of new drug treatment strategies to rapidly kill Plasmodium spp. malaria parasites is urgently needed. Azithromycin is a clinically used macrolide antibiotic proposed as a partner drug for combination therapy in malaria, which has also been tested as monotherapy. However, its slow-killing 'delayed-death' activity against the parasite's apicoplast organelle and suboptimal activity as monotherapy limit its application as a potential malaria treatment. Here, we explore a panel of azithromycin analogues and demonstrate that chemical modifications can be used to greatly improve the speed and potency of antimalarial action. RESULTS Investigation of 84 azithromycin analogues revealed nanomolar quick-killing potency directed against the very earliest stage of parasite development within red blood cells. Indeed, the best analogue exhibited 1600-fold higher potency than azithromycin with less than 48 hrs treatment in vitro. Analogues were effective against zoonotic Plasmodium knowlesi malaria parasites and against both multi-drug and artemisinin-resistant Plasmodium falciparum lines. Metabolomic profiles of azithromycin analogue-treated parasites suggested activity in the parasite food vacuole and mitochondria were disrupted. Moreover, unlike the food vacuole-targeting drug chloroquine, azithromycin and analogues were active across blood-stage development, including merozoite invasion, suggesting that these macrolides have a multi-factorial mechanism of quick-killing activity. The positioning of functional groups added to azithromycin and its quick-killing analogues altered their activity against bacterial-like ribosomes but had minimal change on 'quick-killing' activity. Apicoplast minus parasites remained susceptible to both azithromycin and its analogues, further demonstrating that quick-killing is independent of apicoplast-targeting, delayed-death activity. CONCLUSION We show that azithromycin and analogues can rapidly kill malaria parasite asexual blood stages via a fast action mechanism. Development of azithromycin and analogues as antimalarials offers the possibility of targeting parasites through both a quick-killing and delayed-death mechanism of action in a single, multifactorial chemotype.
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Affiliation(s)
- Amy L Burns
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, 3050, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, 3050, Australia
| | - Ghizal Siddiqui
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Amanda E De Paoli
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Dovile Anderson
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Benjamin Liffner
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia
| | - Richard Harvey
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, Victoria, 3004, Australia
- Department of Medicine, University of Melbourne, Melbourne, Australia
- Central Clinical School and Department of Microbiology, Monash University, Melbourne, Australia
| | - Darren J Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Christopher D Goodman
- School of Biosciences, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Geoffrey I McFadden
- School of Biosciences, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia.
- Burnet Institute, Melbourne, Victoria, 3004, Australia.
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32
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Ressurreição M, Thomas JA, Nofal SD, Flueck C, Moon RW, Baker DA, van Ooij C. Use of a highly specific kinase inhibitor for rapid, simple and precise synchronization of Plasmodium falciparum and Plasmodium knowlesi asexual blood-stage parasites. PLoS One 2020; 15:e0235798. [PMID: 32673324 PMCID: PMC7365400 DOI: 10.1371/journal.pone.0235798] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
During the course of the asexual erythrocytic stage of development, Plasmodium spp. parasites undergo a series of morphological changes and induce alterations in the host cell. At the end of this stage, the parasites egress from the infected cell, after which the progeny invade a new host cell. These processes are rapid and occur in a time-dependent manner. Of particular importance, egress and invasion of erythrocytes by the parasite are difficult to capture in an unsynchronized culture, or even a culture that has been synchronized within a window of one to several hours. Therefore, precise synchronization of parasite cultures is of paramount importance for the investigation of these processes. Here we describe a method for synchronizing Plasmodium falciparum and Plasmodium knowlesi asexual blood stage parasites with ML10, a highly specific inhibitor of the cGMP-dependent protein kinase (PKG) that arrests parasite growth approximately 15 minutes prior to egress. This inhibitor allows parasite cultures to be synchronized so that all parasites are within a window of development of several minutes, with a simple wash step. Furthermore, we show that parasites remain viable for several hours after becoming arrested by the compound and that ML10 has advantages, owing to its high specificity and low EC50, over the previously used PKG inhibitor Compound 2. Here, we demonstrate that ML10 is an invaluable tool for the study of Plasmodium spp. asexual blood stage biology and for the routine synchronization of P. falciparum and P. knowlesi cultures.
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Affiliation(s)
- Margarida Ressurreição
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - James A. Thomas
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Stephanie D. Nofal
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christian Flueck
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Robert W. Moon
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David A. Baker
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christiaan van Ooij
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
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33
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Galinski MR. Functional genomics of simian malaria parasites and host-parasite interactions. Brief Funct Genomics 2020; 18:270-280. [PMID: 31241151 PMCID: PMC6859816 DOI: 10.1093/bfgp/elz013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/21/2019] [Accepted: 05/20/2019] [Indexed: 12/15/2022] Open
Abstract
Two simian malaria parasite species, Plasmodium knowlesi and Plasmodium cynomolgi, cause zoonotic infections in Southeast Asia, and they have therefore gained recognition among scientists and public health officials. Notwithstanding, these species and others including Plasmodium coatneyi have served for decades as sources of knowledge on the biology, genetics and evolution of Plasmodium, and the diverse ramifications and outcomes of malaria in their monkey hosts. Experimental analysis of these species can help to fill gaps in knowledge beyond what may be possible studying the human malaria parasites or rodent parasite species. The genome sequences for these simian malaria parasite species were reported during the last decade, and functional genomics research has since been pursued. Here research on the functional genomics analysis involving these species is summarized and their importance is stressed, particularly for understanding host–parasite interactions, and potentially testing novel interventions. Importantly, while Plasmodium falciparum and Plasmodium vivax can be studied in small New World monkeys, the simian malaria parasites can be studied more effectively in the larger Old World monkey macaque hosts, which are more closely related to humans. In addition to ex vivo analyses, experimental scenarios can include passage through Anopheline mosquito hosts and longitudinal infections in monkeys to study acute and chronic infections, as well as relapses, all in the context of the in vivo host environment. Such experiments provide opportunities for understanding functional genomic elements that govern host–parasite interactions, immunity and pathogenesis in-depth, addressing hypotheses not possible from in vitro cultures or cross-sectional clinical studies with humans.
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Affiliation(s)
- Mary R Galinski
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.,Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
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Cai FY, DeSimone TM, Hansen E, Jennings CV, Bei AK, Ahouidi AD, Mboup S, Duraisingh MT, Buckee CO. Accounting for red blood cell accessibility reveals distinct invasion strategies in Plasmodium falciparum strains. PLoS Comput Biol 2020; 16:e1007702. [PMID: 32315315 PMCID: PMC7194430 DOI: 10.1371/journal.pcbi.1007702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 05/01/2020] [Accepted: 01/31/2020] [Indexed: 11/19/2022] Open
Abstract
The growth of the malaria parasite Plasmodium falciparum in human blood causes all the symptoms of malaria. To proliferate, non-motile parasites must have access to susceptible red blood cells, which they invade using pairs of parasite ligands and host receptors that define invasion pathways. Parasites can switch invasion pathways, and while this flexibility is thought to facilitate immune evasion, it may also reflect the heterogeneity of red blood cell surfaces within and between hosts. Host genetic background affects red blood cell structure, for example, and red blood cells also undergo dramatic changes in morphology and receptor density as they age. The in vivo consequences of both the accessibility of susceptible cells, and their heterogeneous susceptibility, remain unclear. Here, we measured invasion of laboratory strains of P. falciparum relying on distinct invasion pathways into red blood cells of different ages. We estimated invasion efficiency while accounting for red blood cell accessibility to parasites. This approach revealed different tradeoffs made by parasite strains between the fraction of cells they can invade and their invasion rate into them, and we distinguish "specialist" strains from "generalist" strains in this context. We developed a mathematical model to show that generalist strains would lead to higher peak parasitemias in vivo compared to specialist strains with similar overall proliferation rates. Thus, the ecology of red blood cells may play a key role in determining the rate of P. falciparum parasite proliferation and malaria virulence.
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Affiliation(s)
- Francisco Y. Cai
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Tiffany M. DeSimone
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Elsa Hansen
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Cameron V. Jennings
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Amy K. Bei
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Ambroise D. Ahouidi
- Laboratory of Bacteriology and Virology, Le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Souleymane Mboup
- Laboratory of Bacteriology and Virology, Le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Manoj T. Duraisingh
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Caroline O. Buckee
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
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35
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Odedra A, McCarthy JS. Safety Considerations for Malaria Volunteer Infection Studies: A Mini-Review. Am J Trop Med Hyg 2020; 102:934-939. [PMID: 32189610 DOI: 10.4269/ajtmh.19-0351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Malaria clinical studies entailing the experimental infection of healthy volunteers with Plasmodium parasites by bites from infected mosquitos, injection of cryopreserved sporozoites, or injection of blood-stage parasites provide valuable information for vaccine and drug development. Success of these studies depends on maintaining safety. In this mini-review, we discuss the safety risks and associated mitigation strategies of these three types of experimental malaria infection. We aimed to inform researchers and regulators who are currently involved in or are planning to establish experimental malaria infection studies in endemic or non-endemic settings.
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Affiliation(s)
- Anand Odedra
- QIMR Berghofer Medical Research Institute, Herston, Australia.,Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - James S McCarthy
- The University of Queensland, St Lucia, Australia.,QIMR Berghofer Medical Research Institute, Herston, Australia
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36
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Brown AC, Moore CC, Guler JL. Cholesterol-dependent enrichment of understudied erythrocytic stages of human Plasmodium parasites. Sci Rep 2020; 10:4591. [PMID: 32165667 PMCID: PMC7067793 DOI: 10.1038/s41598-020-61392-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/26/2020] [Indexed: 01/01/2023] Open
Abstract
For intracellular pathogens, the host cell provides needed protection and nutrients. A major challenge of intracellular parasite research is collection of high parasite numbers separated from host contamination. This situation is exemplified by the malaria parasite, which spends a substantial part of its life cycle inside erythrocytes as rings, trophozoites, and schizonts, before egress and reinvasion. Erythrocytic Plasmodium parasite forms refractory to enrichment remain understudied due to high host contamination relative to low parasite numbers. Here, we present a method for separating all stages of Plasmodium-infected erythrocytes through lysis and removal of uninfected erythrocytes. The Streptolysin O-Percoll (SLOPE) method is effective on previously inaccessible forms, including circulating rings from malaria-infected patients and artemisinin-induced quiescent parasites. SLOPE can be used on multiple parasite species, under multiple media formulations, and lacks measurable impacts on parasite viability. We demonstrate erythrocyte membrane cholesterol levels modulate the preferential lysis of uninfected host cells by SLO, and therefore modulate the effectiveness of SLOPE. Targeted metabolomics of SLOPE-enriched ring stage samples confirms parasite-derived metabolites are increased and contaminating host material is reduced compared to non-enriched samples. Due to consumption of cholesterol by other intracellular bacteria and protozoa, SLOPE holds potential for improving research on organisms beyond Plasmodium.
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Affiliation(s)
- Audrey C Brown
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Christopher C Moore
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | - Jennifer L Guler
- Department of Biology, University of Virginia, Charlottesville, VA, USA. .,Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA.
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37
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Mohring F, Hart MN, Patel A, Baker DA, Moon RW. CRISPR-Cas9 Genome Editing of Plasmodium knowlesi. Bio Protoc 2020; 10:e3522. [PMID: 33654746 PMCID: PMC7842605 DOI: 10.21769/bioprotoc.3522] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/15/2019] [Accepted: 12/23/2019] [Indexed: 12/28/2022] Open
Abstract
Plasmodium knowlesi is a zoonotic malaria parasite in Southeast Asia that can cause severe and fatal malaria in humans. The main hosts are Macaques, but modern diagnostic tools reveal increasing numbers of human infections. After P. falciparum, P. knowlesi is the only other malaria parasite capable of being maintained in long term in vitro culture with human red blood cells (RBCs). Its closer ancestry to other non-falciparum human malaria parasites, more balanced AT-content, larger merozoites and higher transfection efficiencies, gives P. knowlesi some key advantages over P. falciparum for the study of malaria parasite cell/molecular biology. Here, we describe the generation of marker-free CRISPR gene-edited P. knowlesi parasites, the fast and scalable production of transfection constructs and analysis of transfection efficiencies. Our protocol allows rapid, reliable and unlimited rounds of genome editing in P. knowlesi requiring only a single recyclable selection marker.
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Affiliation(s)
- Franziska Mohring
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Melissa N. Hart
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Avnish Patel
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - David A. Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Robert W. Moon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
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38
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Chan LJ, Dietrich MH, Nguitragool W, Tham WH. Plasmodium vivax Reticulocyte Binding Proteins for invasion into reticulocytes. Cell Microbiol 2019; 22:e13110. [PMID: 31469946 PMCID: PMC7003471 DOI: 10.1111/cmi.13110] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/25/2019] [Accepted: 08/25/2019] [Indexed: 12/22/2022]
Abstract
Plasmodium vivax is responsible for most of the malaria infections outside Africa and is currently the predominant malaria parasite in countries under elimination programs. P. vivax preferentially enters young red cells called reticulocytes. Advances in understanding the molecular and cellular mechanisms of entry are hampered by the inability to grow large numbers of P. vivax parasites in a long‐term in vitro culture. Recent progress in understanding the biology of the P. vivax Reticulocyte Binding Protein (PvRBPs) family of invasion ligands has led to the identification of a new invasion pathway into reticulocytes, an understanding of their structural architecture and PvRBPs as targets of the protective immune response to P. vivax infection. This review summarises current knowledge on the role of reticulocytes in P. vivax infection, the function of the PvRBP family of proteins in generating an immune response in human populations, and the characterization of anti‐PvRBP antibodies in blocking parasite invasion.
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Affiliation(s)
- Li-Jin Chan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Melanie H Dietrich
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Wang Nguitragool
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wai-Hong Tham
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
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39
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Mohring F, Hart MN, Rawlinson TA, Henrici R, Charleston JA, Diez Benavente E, Patel A, Hall J, Almond N, Campino S, Clark TG, Sutherland CJ, Baker DA, Draper SJ, Moon RW. Rapid and iterative genome editing in the malaria parasite Plasmodium knowlesi provides new tools for P. vivax research. eLife 2019; 8:45829. [PMID: 31205002 PMCID: PMC6579517 DOI: 10.7554/elife.45829] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/28/2019] [Indexed: 12/14/2022] Open
Abstract
Tackling relapsing Plasmodium vivax and zoonotic Plasmodium knowlesi infections is critical to reducing malaria incidence and mortality worldwide. Understanding the biology of these important and related parasites was previously constrained by the lack of robust molecular and genetic approaches. Here, we establish CRISPR-Cas9 genome editing in a culture-adapted P. knowlesi strain and define parameters for optimal homology-driven repair. We establish a scalable protocol for the production of repair templates by PCR and demonstrate the flexibility of the system by tagging proteins with distinct cellular localisations. Using iterative rounds of genome-editing we generate a transgenic line expressing P. vivax Duffy binding protein (PvDBP), a lead vaccine candidate. We demonstrate that PvDBP plays no role in reticulocyte restriction but can alter the macaque/human host cell tropism of P. knowlesi. Critically, antibodies raised against the P. vivax antigen potently inhibit proliferation of this strain, providing an invaluable tool to support vaccine development.
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Affiliation(s)
- Franziska Mohring
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Melissa Natalie Hart
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Ryan Henrici
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - James A Charleston
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Ernest Diez Benavente
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Avnish Patel
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Joanna Hall
- Division of Infectious Disease Diagnostics, National Institute for Biological Standards and Control, Health Protection Agency, Hertfordshire, United Kingdom
| | - Neil Almond
- Division of Infectious Disease Diagnostics, National Institute for Biological Standards and Control, Health Protection Agency, Hertfordshire, United Kingdom
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Taane G Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Colin J Sutherland
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David A Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Simon J Draper
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Robert William Moon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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40
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Verzier LH, Coyle R, Singh S, Sanderson T, Rayner JC. Plasmodium knowlesi as a model system for characterising Plasmodium vivax drug resistance candidate genes. PLoS Negl Trop Dis 2019; 13:e0007470. [PMID: 31158222 PMCID: PMC6564043 DOI: 10.1371/journal.pntd.0007470] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 06/13/2019] [Accepted: 05/15/2019] [Indexed: 12/29/2022] Open
Abstract
Plasmodium vivax causes the majority of malaria outside Africa, but is poorly understood at a cellular level partly due to technical difficulties in maintaining it in in vitro culture conditions. In the past decades, drug resistant P. vivax parasites have emerged, mainly in Southeast Asia, but while some molecular markers of resistance have been identified, none have so far been confirmed experimentally, which limits interpretation of the markers, and hence our ability to monitor and control the spread of resistance. Some of these potential markers have been identified through P. vivax genome-wide population genetic analyses, which highlighted genes under recent evolutionary selection in Southeast Asia, where chloroquine resistance is most prevalent. These genes could be involved in drug resistance, but no experimental proof currently exists to support this hypothesis. In this study, we used Plasmodium knowlesi, the most closely related species to P. vivax that can be cultured in human erythrocytes, as a model system to express P. vivax genes and test for their role in drug resistance. We adopted a strategy of episomal expression, and were able to express fourteen P. vivax genes, including two allelic variants of several hypothetical resistance genes. Their expression level and localisation were assessed, confirming cellular locations conjectured from orthologous species, and suggesting locations for several previously unlocalised proteins, including an apical location for PVX_101445. These findings establish P. knowlesi as a suitable model for P. vivax protein expression. We performed chloroquine and mefloquine drug assays, finding no significant differences in drug sensitivity: these results could be due to technical issues, or could indicate that these genes are not actually involved in drug resistance, despite being under positive selection pressure in Southeast Asia. These data confirm that in vitro P. knowlesi is a useful tool for studying P. vivax biology. Its close evolutionary relationship to P. vivax, high transfection efficiency, and the availability of markers for colocalisation, all make it a powerful model system. Our study is the first of its kind using P. knowlesi to study unknown P. vivax proteins and investigate drug resistance mechanisms.
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Affiliation(s)
- Lisa H. Verzier
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Rachael Coyle
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Shivani Singh
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Theo Sanderson
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Julian C. Rayner
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
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41
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Ngernna S, Chim-Ong A, Roobsoong W, Sattabongkot J, Cui L, Nguitragool W. Efficient synchronization of Plasmodium knowlesi in vitro cultures using guanidine hydrochloride. Malar J 2019; 18:148. [PMID: 31023359 PMCID: PMC6482532 DOI: 10.1186/s12936-019-2783-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/16/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Long-term in vitro culture of blood stage Plasmodium parasites invariably leads to asynchronous parasite development. The most often used technique to synchronize Plasmodium falciparum culture is sorbitol treatment, which differentially induces osmotic lysis of trophozoite- and schizont-infected red blood cells due to presence of the new permeation pathways in the membranes of these cells. However, sorbitol treatment does not work well when used to synchronize the culture-adapted Plasmodium knowlesi A1-H.1 line. METHODS A number of common solutes were tested in lieu of sorbitol for synchronization of P. knowlesi A1-H.1 ring stage. RESULTS Guanidine hydrochloride was found to selectively lyse trophozoite- and schizont-infected red blood cells, yielding highly synchronous and viable rings. CONCLUSIONS A method for synchronization of P. knowlesi in human red blood cells was developed. Requiring only common laboratory reagents, this method is simple and should be applicable to most laboratory settings.
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Affiliation(s)
- Sutharinee Ngernna
- Department of Molecular Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Anongruk Chim-Ong
- Department of Molecular Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Wang Nguitragool
- Department of Molecular Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand.
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42
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Davidson G, Chua TH, Cook A, Speldewinde P, Weinstein P. Defining the ecological and evolutionary drivers of Plasmodium knowlesi transmission within a multi-scale framework. Malar J 2019; 18:66. [PMID: 30849978 PMCID: PMC6408765 DOI: 10.1186/s12936-019-2693-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 03/01/2019] [Indexed: 01/12/2023] Open
Abstract
Plasmodium knowlesi is a zoonotic malaria parasite normally residing in long-tailed and pig-tailed macaques (Macaca fascicularis and Macaca nemestrina, respectively) found throughout Southeast Asia. Recently, knowlesi malaria has become the predominant malaria affecting humans in Malaysian Borneo, being responsible for approximately 70% of reported cases. Largely as a result of anthropogenic land use changes in Borneo, vectors which transmit the parasite, along with macaque hosts, are both now frequently found in disturbed forest habitats, or at the forest fringes, thus having more frequent contact with humans. Having access to human hosts provides the parasite with the opportunity to further its adaption to the human immune system. The ecological drivers of the transmission and spread of P. knowlesi are operating over many different spatial (and, therefore, temporal) scales, from the molecular to the continental. Strategies to prevent and manage zoonoses, such as P. knowlesi malaria require interdisciplinary research exploring the impact of land use change and biodiversity loss on the evolving relationship between parasite, reservoir hosts, vectors, and humans over multiple spatial scales.
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Affiliation(s)
- Gael Davidson
- School of Agriculture and Environment, University of Western Australia, Stirling Terrace, Albany, WA, 6330, Australia. .,School of Population and Global Health, University of Western Australia, Perth, Australia.
| | - Tock H Chua
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Angus Cook
- School of Population and Global Health, University of Western Australia, Perth, Australia
| | - Peter Speldewinde
- School of Agriculture and Environment, University of Western Australia, Stirling Terrace, Albany, WA, 6330, Australia
| | - Philip Weinstein
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
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Plasmodium knowlesi exhibits distinct in vitro drug susceptibility profiles from those of Plasmodium falciparum. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 9:93-99. [PMID: 30831468 PMCID: PMC6403410 DOI: 10.1016/j.ijpddr.2019.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/14/2019] [Accepted: 02/18/2019] [Indexed: 12/16/2022]
Abstract
New antimalarial agents are identified and developed after extensive testing on Plasmodium falciparum parasites that can be grown in vitro. These susceptibility studies are important to inform lead optimisation and support further drug development. Until recently, little was known about the susceptibility of non-falciparum species as these had not been adapted to in vitro culture. The recent culture adaptation of P. knowlesi has therefore offered an opportunity to routinely define the drug susceptibility of this species, which is phylogenetically closer to all other human malarias than is P. falciparum. We compared the in vitro susceptibility of P. knowlesi and P. falciparum to a range of established and novel antimalarial agents under identical assay conditions. We demonstrated that P. knowlesi is significantly less susceptible than P. falciparum to six of the compounds tested; and notably these include three ATP4 inhibitors currently under development as novel antimalarial agents, and one investigational antimalarial, AN13762, which is 67 fold less effective against P. knowlesi. For the other compounds there was a less than two-fold difference in susceptibility between species. We then compared the susceptibility of a recent P. knowlesi isolate, UM01, to that of the well-established, older A1-H.1 clone. This recent isolate showed similar in vitro drug susceptibility to the A1-H.1 clone, supporting the ongoing use of the better characterised clone to further study drug susceptibility. Lastly, we used isobologram analysis to explore the interaction of a selection of drug combinations and showed similar drug interactions across species. The species differences in drug susceptibility reported by us here and previously, support adding in vitro drug screens against P. knowlesi to those using P. falciparum strains to inform new drug discovery and lead optimisation. P. knowlesi >6-fold less susceptible to several ATP4 inhibitors than P. falciparum. P. knowlesi equally susceptible to artemisinins and synthetic endoperoxides. Isobolograms show similar drug interactions for P. knowlesi and P. falciparum. New P. knowlesi isolate (UM01) similarly susceptible to antimalarials as A1-H.1
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44
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Amir A, Cheong FW, de Silva JR, Liew JWK, Lau YL. Plasmodium knowlesi malaria: current research perspectives. Infect Drug Resist 2018; 11:1145-1155. [PMID: 30127631 PMCID: PMC6089103 DOI: 10.2147/idr.s148664] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Originally known to cause simian malaria, Plasmodium knowlesi is now known as the fifth human malaria species. Since the publishing of a report that largely focused on human knowlesi cases in Sarawak in 2004, many more human cases have been reported in nearly all of the countries in Southeast Asia and in travelers returning from these countries. The zoonotic nature of this infection hinders malaria elimination efforts. In order to grasp the current perspective of knowlesi malaria, this literature review explores the different aspects of the disease including risk factors, diagnosis, treatment, and molecular and functional studies. Current studies do not provide sufficient data for an effective control program. Therefore, future direction for knowlesi research is highlighted here with a final aim of controlling, if not eliminating, the parasite.
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Affiliation(s)
- Amirah Amir
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia,
| | - Fei Wen Cheong
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia,
| | - Jeremy Ryan de Silva
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia,
| | - Jonathan Wee Kent Liew
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia,
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia,
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Lyth O, Vizcay-Barrena G, Wright KE, Haase S, Mohring F, Najer A, Henshall IG, Ashdown GW, Bannister LH, Drew DR, Beeson JG, Fleck RA, Moon RW, Wilson DW, Baum J. Cellular dissection of malaria parasite invasion of human erythrocytes using viable Plasmodium knowlesi merozoites. Sci Rep 2018; 8:10165. [PMID: 29976932 PMCID: PMC6033891 DOI: 10.1038/s41598-018-28457-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 06/22/2018] [Indexed: 12/21/2022] Open
Abstract
Plasmodium knowlesi, a zoonotic parasite causing severe-to-lethal malaria disease in humans, has only recently been adapted to continuous culture with human red blood cells (RBCs). In comparison with the most virulent human malaria, Plasmodium falciparum, there are, however, few cellular tools available to study its biology, in particular direct investigation of RBC invasion by blood-stage P. knowlesi merozoites. This leaves our current understanding of biological differences across pathogenic Plasmodium spp. incomplete. Here, we report a robust method for isolating viable and invasive P. knowlesi merozoites to high purity and yield. Using this approach, we present detailed comparative dissection of merozoite invasion (using a variety of microscopy platforms) and direct assessment of kinetic differences between knowlesi and falciparum merozoites. We go on to assess the inhibitory potential of molecules targeting discrete steps of invasion in either species via a quantitative invasion inhibition assay, identifying a class of polysulfonate polymer able to efficiently inhibit invasion in both, providing a foundation for pan-Plasmodium merozoite inhibitor development. Given the close evolutionary relationship between P. knowlesi and P. vivax, the second leading cause of malaria-related morbidity, this study paves the way for inter-specific dissection of invasion by all three major pathogenic malaria species.
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Affiliation(s)
- Oliver Lyth
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Gema Vizcay-Barrena
- Centre for Ultrastructural Imaging, Guy's Campus, King's College London, London, UK
| | - Katherine E Wright
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Silvia Haase
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Franziska Mohring
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Adrian Najer
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Isabelle G Henshall
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - George W Ashdown
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Lawrence H Bannister
- Centre for Ultrastructural Imaging, Guy's Campus, King's College London, London, UK
| | - Damien R Drew
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia.,Central Clinical School, Monash University, Victoria, Australia
| | - James G Beeson
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia.,Central Clinical School, Monash University, Victoria, Australia
| | - Roland A Fleck
- Centre for Ultrastructural Imaging, Guy's Campus, King's College London, London, UK
| | - Robert W Moon
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, Australia. .,Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia.
| | - Jake Baum
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK.
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46
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van Schalkwyk DA, Moon RW, Blasco B, Sutherland CJ. Comparison of the susceptibility of Plasmodium knowlesi and Plasmodium falciparum to antimalarial agents. J Antimicrob Chemother 2018; 72:3051-3058. [PMID: 28961865 PMCID: PMC5890772 DOI: 10.1093/jac/dkx279] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/11/2017] [Indexed: 01/09/2023] Open
Abstract
Background The simian malaria parasite Plasmodium knowlesi is now a well-recognized pathogen of humans in South-East Asia. Clinical infections appear adequately treated with existing drug regimens, but the evidence base for this practice remains weak. The availability of P. knowlesi cultures adapted to continuous propagation in human erythrocytes enables specific studies of in vitro susceptibility of the species to antimalarial agents, and could provide a surrogate system for testing investigational compounds against Plasmodium vivax and other non-Plasmodium falciparum infections that cannot currently be propagated in vitro. Objectives We sought to optimize protocols for in vitro susceptibility testing of P. knowlesi and to contrast outputs with those obtained for P. falciparum under comparable test conditions. Methods Growth monitoring of P. knowlesi in vitro was by DNA quantification using a SYBR Green fluorescent assay or by colorimetric detection of the lactate dehydrogenase enzyme. For comparison, P. falciparum was tested under conditions identical to those used for P. knowlesi. Results The SYBR Green I assay proved the most robust format over one (27 h) or two (54 h) P. knowlesi life cycles. Unexpectedly, P. knowlesi displays significantly greater susceptibility to the dihydrofolate reductase inhibitors pyrimethamine, cycloguanil and trimethoprim than does P. falciparum, but is less susceptible to the selective agents blasticidin and DSM1 used in parasite transfections. Inhibitors of dihydroorotate dehydrogenase also demonstrate lower activity against P. knowlesi. Conclusions The fluorescent assay system validated here identified species-specific P. knowlesi drug susceptibility profiles and can be used for testing investigational compounds for activity against non-P. falciparum malaria.
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Affiliation(s)
- Donelly A van Schalkwyk
- Department of Immunology & Infection, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Robert W Moon
- Department of Immunology & Infection, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Benjamin Blasco
- Medicines for Malaria Venture, 20 rte de Pré Bois, Geneva CH 1215, Switzerland
| | - Colin J Sutherland
- Department of Immunology & Infection, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.,Department of Clinical Parasitology, Hospital for Tropical Diseases, Mortimer Market Centre, Capper Street, London WC1E 6JB, UK
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47
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Erythrocytes lacking the Langereis blood group protein ABCB6 are resistant to the malaria parasite Plasmodium falciparum. Commun Biol 2018; 1:45. [PMID: 30271928 PMCID: PMC6123700 DOI: 10.1038/s42003-018-0046-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/04/2018] [Indexed: 12/17/2022] Open
Abstract
The ATP-binding cassette transporter ABCB6 was recently discovered to encode the Langereis (Lan) blood group antigen. Lan null individuals are asymptomatic, and the function of ABCB6 in mature erythrocytes is not understood. Here, we assessed ABCB6 as a host factor for Plasmodium falciparum malaria parasites during erythrocyte invasion. We show that Lan null erythrocytes are highly resistant to invasion by P. falciparum, in a strain-transcendent manner. Although both Lan null and Jr(a-) erythrocytes harbor excess porphyrin, only Lan null erythrocytes exhibit a P. falciparum invasion defect. Further, the zoonotic parasite P. knowlesi invades Lan null and control cells with similar efficiency, suggesting that ABCB6 may mediate P. falciparum invasion through species-specific molecular interactions. Using tandem mass tag-based proteomics, we find that the only consistent difference in membrane proteins between Lan null and control cells is absence of ABCB6. Our results demonstrate that a newly identified naturally occurring blood group variant is associated with resistance to Plasmodium falciparum. Elizabeth Egan and colleagues demonstrate that host ATP binding cassette transporter ABCB6, which encodes the Langereis blood group antigen, promotes erythrocyte invasion by the malaria parasite Plasmodium falciparum. This study suggests that asymptomatic Langereis null individuals may be better protected from malaria.
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Infection of mosquitoes from in vitro cultivated Plasmodium knowlesi H strain. Int J Parasitol 2018; 48:601-610. [PMID: 29723510 DOI: 10.1016/j.ijpara.2018.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/31/2017] [Accepted: 02/20/2018] [Indexed: 12/11/2022]
Abstract
In vitro studies of sexual blood stages of the most fatal malaria species, Plasmodium falciparum, have revealed key processes by which gametocytes develop and transmit infection from humans to anopheline mosquitoes. However, most malaria cases outside sub-Saharan Africa are caused by other Plasmodium spp., frequently Plasmodium vivax and Plasmodium knowlesi, a zoonotic parasite of macaque monkeys. Gametocytes of P. vivax and P. knowlesi exhibit distinct morphology, faster development, and a shorter life span compared with gametocytes of P. falciparum, reflecting the evolutionary separation and biological differences of these species. Unlike P. falciparum, P. vivax cannot be cultivated in vitro, necessitating access to infected primates for laboratory studies. In contrast, P. knowlesi asexual stages have been successfully adapted to cultures in macaque and human red blood cells, but these stages have not been reported to produce gametocytes infective to mosquitoes. Here, we show that gametocyte production and sporadic, low-level mosquito infectivity of a P. knowlesi strain was not improved by application of a "crash" method commonly used to induce gametocytes in P. falciparum cultures. However, Percoll-gradient purified schizonts from this strain yielded highly synchronised populations that, in three of six experiments, produced infections at an average rate of 0.97-9.1 oocysts in Anopheles dirus mosquitoes. Oocyst counts were most abundant in mosquitoes that were fed from the synchronised cultures 36 h after schizont purification. Gametocytes in these cultures occurred at low prevalence and were difficult to observe. Transcription from orthologs of P. falciparum gametocyte-specific markers did not correlate with infectivity of the P. knowlesi parasites to mosquitoes. The ability to infect mosquitoes from in vitro-cultivated P. knowlesi will support research on the unique features of this emerging pathogen and facilitate comparative studies of transmission by the different human malarias.
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Muh F, Ahmed MA, Han JH, Nyunt MH, Lee SK, Lau YL, Kaneko O, Han ET. Cross-species analysis of apical asparagine-rich protein of Plasmodium vivax and Plasmodium knowlesi. Sci Rep 2018; 8:5781. [PMID: 29636493 PMCID: PMC5893618 DOI: 10.1038/s41598-018-23728-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 03/01/2018] [Indexed: 11/09/2022] Open
Abstract
The Plasmodium falciparum apical asparagine (Asn)-rich protein (AARP) is one of malarial proteins, and it has been studied as a candidate of malaria subunit vaccine. Basic characterization of PvAARP has been performed with a focus on its immunogenicity and localization. In this study, we further analyzed the immunogenicity of PvAARP, focusing on the longevity of the antibody response, cross-species immunity and invasion inhibitory activity by using the primate malaria parasite Plasmodium knowlesi. We found that vivax malaria patient sera retained anti-PvAARP antibodies for at least one year without re-infection. Recombinant PvAARP protein was strongly recognized by knowlesi malaria patients. Antibody raised against the P. vivax and P. knowlesi AARP N-termini reacted with the apical side of the P. knowlesi merozoites and inhibited erythrocyte invasion by P. knowlesi in a concentration-dependent manner, thereby suggesting a cross-species nature of anti-PvAARP antibody against PkAARP. These results can be explained by B cell epitopes predicted in conserved surface-exposed regions of the AARP N-terminus in both species. The long-lived anti-PvAARP antibody response, cross-reactivity, and invasion inhibitory activity of anti-PvAARP support a critical role of AARP during the erythrocyte invasion and suggest that PvAARP induces long-lived cross-species protective immunity against P. vivax and P. knowlesi.
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Affiliation(s)
- Fauzi Muh
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Md Atique Ahmed
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Myat Htut Nyunt
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
- Department of Medical Research, Yangon, Myanmar
| | - Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Osamu Kaneko
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea.
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Abstract
Plasmodium species cause malaria by proliferating in human erythrocytes. Invasion of immunologically privileged erythrocytes provides a relatively protective niche as well as access to a rich source of nutrients. Plasmodium spp. target erythrocytes of different ages, but share a common mechanism of invasion. Specific engagement of erythrocyte receptors defines target cell tropism, activating downstream events and resulting in the physical penetration of the erythrocyte, powered by the parasite's actinomyosin-based motor. Here we review the latest in our understanding of the molecular composition of this highly complex and fascinating biological process.
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