Molecular factors that are associated with early developmental arrest of intraerythrocytic Plasmodium falciparum

2013 ◽  
Vol 59 (7) ◽  
pp. 485-493 ◽  
Author(s):  
Hiroko Asahi ◽  
Mohammed Essa Marghany Tolba ◽  
Masanobu Tanabe ◽  
Hiroshi Ohmae
Keyword(s):  
Plasmodium Falciparum ◽  
Fatty Acid ◽  
Developmental Stages ◽  
Copper Ions ◽  
Copper Ion ◽  
Merozoite Surface Protein ◽  
Parasite Development ◽  
Ring Stage ◽  
Critical Function ◽  
Developmental Arrest

Malaria continues to be a devastating disease. We investigated the factors that control intraerythrocytic development of the parasite Plasmodium falciparum by using a chemically defined medium (CDM) containing non-esterified fatty acid(s) (NEFA) and phospholipids with specific fatty acid moieties, to identify substances crucial for parasite development. Different NEFAs in the CDM played distinct roles by altering the development of the parasite at various stages, with effects ranging from complete growth to growth arrest at the ring stage. We used genome-wide transcriptome profiling to identify genes that were differentially expressed among the different developmental stages of the parasite, cultured in the presence of various NEFAs. We predicted 26 transcripts that were associated with the suppression of schizogony, of which 5 transcripts, including merozoite surface protein 2, a putative DEAD/DEAH box RNA helicase, serine repeat antigen 3, a putative copper channel, and palmitoyl acyltransferase, were particularly associated with blockage of trophozoite progression from the ring stage. Furthermore, the involvement of copper ions in developmental arrest was detected by copper-ion-chelating methods, implying a critical function of copper homeostasis in the early growth stage of the parasite. These results should help to elucidate the mechanisms behind the development of P. falciparum.

scholarly journals Plasmodium falciparum Founder Populations in Western Cambodia Have Reduced Artemisinin SensitivityIn Vitro

2014 ◽  
Vol 58 (8) ◽  
pp. 4935-4937 ◽  
Author(s):  
Chanaki Amaratunga ◽  
Benoit Witkowski ◽  
Dalin Dek ◽  
Vorleak Try ◽  
Nimol Khim ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Parasite Clearance ◽  
Parasite Development ◽  
Ring Stage ◽  
Content Type ◽  
Short Course ◽  
Founder Populations ◽  
Admixed Population ◽  
Survival Assay

ABSTRACTReducedPlasmodium falciparumsensitivity to short-course artemisinin (ART) monotherapy manifests as a long parasite clearance half-life. We recently defined three parasite founder populations with long half-lives in Pursat, western Cambodia, where reduced ART sensitivity is prevalent. Using the ring-stage survival assay, we show that these founder populations have reduced ART sensitivityin vitroat the early ring stage of parasite development and that a genetically admixed population contains subsets of parasites with normal or reduced ART sensitivity.

scholarly journals Limonene Arrests Parasite Development and Inhibits Isoprenylation of Proteins in Plasmodium falciparum

2001 ◽  
Vol 45 (9) ◽  
pp. 2553-2558 ◽  
Author(s):  
Ivan Cruz Moura ◽  
Gerhard Wunderlich ◽  
Maria L. Uhrig ◽  
Alicia S. Couto ◽  
Valnice J. Peres ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Modification ◽  
Eukaryotic Cells ◽  
Parasite Development ◽  
Farnesyl Pyrophosphate ◽  
Ring Stage ◽  
Ras Proteins ◽  
Trophozoite Stage ◽  
Isoprenoid Metabolism ◽  
Layer Chromatography

ABSTRACT Isoprenylation is an essential protein modification in eukaryotic cells. Herein, we report that in Plasmodium falciparum, a number of proteins were labeled upon incubation of intraerythrocytic forms with either [3H]farnesyl pyrophosphate or [3H]geranylgeranyl pyrophosphate. By thin-layer chromatography, we showed that attached isoprenoids are partially modified to dolichol and other, uncharacterized, residues, confirming active isoprenoid metabolism in this parasite. Incubation of blood-stage P. falciparum treated with the isoprenylation inhibitor limonene significantly decreased the parasites' progression from the ring stage to the trophozoite stage and at 1.22 mM, 50% of the parasites died after the first cycle. Using Ras- and Rap-specific monoclonal antibodies, putative Rap and Ras proteins of P. falciparum were immunoprecipitated. Upon treatment with 0.5 mM limonene, isoprenylation of these proteins was significantly decreased, possibly explaining the observed arrest of parasite development.

scholarly journals Dissection of Plasmodium falciparum developmental stages with multiple imaging methods

2020 ◽  
Author(s):  
Katharina Preißinger ◽  
Beáta Vértessy ◽  
István Kézsmárki ◽  
Miklós Kellermayer
Keyword(s):  
Plasmodium Falciparum ◽  
Developmental Stages ◽  
Imaging Study ◽  
Close Correlation ◽  
Parasite Development ◽  
Force Microscopy ◽  
Global Challenge ◽  
Atomic Force ◽  
Multiple Imaging ◽  
Infected Rbcs

Efficient malaria treatment is a global challenge, requiring in-depth view into the maturation of malaria parasites during the intraerythrocytic cycle. Exploring structural and functional variations of the parasites through the intraerythrocytic stages and their impact on red blood cell (RBCs) is a cornerstone of antimalarial drug development. In order to trace such changes in fine steps of parasite development, we performed an imaging study of RBCs infected by Plasmodium falciparum, using atomic force microscopy (AFM) and total internal reflection fluorescence microscopy (TIRF), further supplemented with bright field microscopy for the direct assignment of the stages. This multifaceted imaging approach allows to reveal structure–functionality relations via correlations of the parasite maturation with morphological and fluorescence properties of the stages. We established identification patterns characteristic to the different parasite stages based on the height profile of infected RBCs, as obtained by AFM, which show close correlation with typical fluorescence (TIRF) maps of RBCs. Furthermore, we found that hemozoin crystals exhibit a strong optical contrast by quenching fluorescence. We demonstrate that these topographic and optical features also provide a tool to locate the hemozoin crystals within the RBCs and, in turn, to follow their growth.

scholarly journals Plasmodium falciparum Merozoite Surface Protein 8 Is a Ring-Stage Membrane Protein That Localizes to the Parasitophorous Vacuole of Infected Erythrocytes

2005 ◽  
Vol 73 (7) ◽  
pp. 3912-3922 ◽  
Author(s):  
Damien R. Drew ◽  
Paul R. Sanders ◽  
Brendan S. Crabb
Keyword(s):  
Plasmodium Falciparum ◽  
Parasitophorous Vacuole ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Food Vacuole ◽  
Ring Stage ◽  
C Terminus ◽  
Falciparum Merozoite ◽  
Merozoite Antigens ◽  
Epidermal Growth

ABSTRACT To date, the following seven glycosylphosphatidylinositol (GPI)-anchored merozoite antigens have been described in Plasmodium falciparum: merozoite-associated surface protein 1 (MSP-1), MSP-2, MSP-4, MSP-5, MSP-8, MSP-10, and the rhoptry-associated membrane antigen. Of these, MSP-1, MSP-8, and MSP-10 possess a double epidermal growth factor (EGF)-like domain at the C terminus, and these modules are considered potential targets of protective immunity. In this study, we found that surprisingly, P. falciparum MSP-8 is transcribed and translated in the ring stage and is absent from the surface of merozoites. MSP-8 is the only GPI-anchored protein known to be expressed at this time. It is synthesized as a mature 80-kDa protein which is rapidly processed to a C-terminal 17-kDa species that contains the double EGF module. As determined by a combination of immunofluorescence and membrane purification approaches, it appears likely that MSP-8 initially localizes to the parasite plasma membrane in the ring stage. Although the C-terminal 17-kDa fragment is present in more mature stages, at these times it is found in the food vacuole. We successfully disrupted the MSP-8 gene in P. falciparum, a process that validated the specificity of the antibodies used in this study and also demonstrated that MSP-8 does not play a role essential to maintenance of the erythrocyte cycle. This finding, together with the observation that MSP-8 is exclusively intracellular, casts doubt over the viability of this antigen as a vaccine. However, it is still possible that MSP-8 is involved in an early parasitophorous vacuole function that is significant for pathogenesis in the human host.

scholarly journals Characterization of Glycoproteins of Native 19kDa C-Terminal Merozoite Surface Protein-1 from Native Antigen of Plasmodium falciparum

2019 ◽  
Author(s):  
Sahar Tajik ◽  
Sedigheh Sadeghi ◽  
Ayda Iravani ◽  
Mitra Khalili ◽  
Mohammad Arjmand ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Large Scale ◽  
Vaccine Development ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Surface Proteins ◽  
Ring Stage ◽  
Native Form ◽  
Sds Page

Background: Plasmodium falciparum is the protozoan parasite which causes malignant malaria of medical concern. Prime candidates for recombinant vaccine development are asexual stage antigens of P. falciparum, for example, merozoite surface proteins (MSP1 and MSP2) not given satisfactory results to date. In this study, the 19kDa C-terminal of MSP1, a vaccine candidate was purified in its native form in the ring stage, and its glycoproteins studied. Methods: The study was carried out at the Biochemistry Department of Pasteur Institute of Iran in the years 2015–2016. Large scale culture of P. falciparum was performed in vitro with 80% ring stage parasitemia. Isopycnic ultracentrifuga­tion with 36% sucrose and analytical SDS-PAGE on the supernatant and precipitate performed, and the 19kDa antigen was obtained by cutting it from strips of preparative SDS gels. Purified protein was concentrated and analyzed by SDS-PAGE and immunoblotting, using antibodies raised to recombinant C-terminal MSP1. Results: The purified protein gave a single band of 19kDa antigen as shown by silver staining of SDS-PAGE and a sin­gle bond in immunoblotting. Bioinformatics also confirmed the likelihood of the presence of glycans on the antigen. Conclusion: The presence of N and O-glycoproteins were detected by Q proteome kit. This work was done on the ring stage, and earlier workers confirmed the presence of glycoproteins on MSP1 in the other stages. This glycosylation is present in all stages, and maybe incomplete protection elicited by recombinant MSP1 antigens is due to lack of N and O-glycoproteins.

scholarly journals Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro

Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1250-1255 ◽  
Author(s):  
S Whitehead ◽  
TE Peto
Keyword(s):  
Plasmodium Falciparum ◽  
Growth Inhibition ◽  
Antimalarial Activity ◽  
Clinical Malaria ◽  
Inhibitory Effect ◽  
Parasite Development ◽  
And Control ◽  
Speed Of Onset

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.

scholarly journals An Investigation on Design and Characterization of a Highly Selective LED Optical Sensor for Copper Ions in Aqueous Solutions

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1099
Author(s):  
Sheng-Chun Hung ◽  
Chih-Cheng Lu ◽  
Yu-Ting Wu
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Copper Ions ◽  
Incident Light ◽  
Copper Ion ◽  
Intensity Change ◽  
Optical Absorbance ◽  
Sensing System ◽  
Optic Sensor ◽  
Cu Ions

The optical characteristics of copper ion detection, such as the photometric absorbance of specific wavelengths, exhibit significant intensity change upon incident light into the aqueous solutions with different concentrations of metal ions due to the electron transition in the orbit. In this study, we developed a low-cost, small-size and fast-response photoelectric sensing prototype as an optic sensor for copper (Cu) ions detection by utilizing the principle of optical absorption. We quantified the change of optical absorbance from infra-red (IR) light emitting diodes (LEDs) upon different concentrations of copper ions and the transmitted optical signals were transferred to the corresponding output voltage through a phototransistor and circuit integrated in the photoelectric sensing system. The optic sensor for copper (Cu) ions demonstrated not only excellent specificity with other metal ions such as cadmium (Cd), nickel (Ni), iron (Fe) and chloride (Cl) ions in the same aqueous solution but also satisfactory linearity and reproducibility. The sensitivity of the preliminary sensing system for copper ions was 29 mV/ppm from 0 to 1000 ppm. In addition, significant ion-selective characteristics and anti-interference capability were also observed in the experiments by the proposed approach.

scholarly journals Allelic diversity of merozoite surface protein genes (msp1 and msp2) and clinical manifestations of Plasmodium falciparum malaria cases in Aceh, Indonesia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Kurnia Fitri Jamil ◽  
Nandha Rizki Pratama ◽  
Sylvia Sance Marantina ◽  
Harapan Harapan ◽  
Muhammad Riza Kurniawan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Liver Function ◽  
Severe Malaria ◽  
Clinical Manifestation ◽  
Allelic Diversity ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Malaria Control Programme ◽  
Co Morbidity ◽  
Aceh Province

Abstract Background The malaria control programme in Indonesia has successfully brought down malaria incidence in many parts in Indonesia, including Aceh Province. Clinical manifestation of reported malaria cases in Aceh varied widely from asymptomatic, mild uncomplicated to severe and fatal complications. The present study aims to explore the allelic diversity of merozoite surface protein 1 gene (msp1) and msp2 among the Plasmodium falciparum isolates in Aceh Province and to determine their potential correlation with the severity of malaria clinical manifestation. Methods Screening of over 500 malaria cases admitted to the hospitals in 11 districts hospital within Aceh Province during 2013–2015, identified 90 cases of P. falciparum mono-infection without any co-morbidity. The subjects were clinically phenotyped and parasite DNA was extracted and polymerase chain reaction (PCR) amplified for the msp1 and msp2 allelic subfamilies. Results Analysis of clinical manifestation revealed that fever-chill is the most frequent symptom. Based on WHO criteria showed 19 cases were classified as severe and 71 as mild malaria. Analysis of msp1 gene revealed the presence of K1 allele subfamily in 34 subjects, MAD20 in 42 subjects, RO33 in 1 subject, and mixed allelic of K1 + MAD20 in 5 subjects, K1 + RO33 in 4 subjects, and MAD20 + RO33 in 4 subjects. Analysis of msp2 gene revealed 34 subjects carried the FC27 allelic subfamily, 37 subjects carried the 3D7 and 19 subjects carried the mixed FC27 + 3D7. Analysis of multiplicity of infection revealed that msp1 alleles is slightly higher than msp2 with the mean of MOI were 2.69 and 2.27, respectively. Statistical analysis to determine the association between each clinical manifestation and msp1 and msp2 alleles revealed that liver function abnormal value was associated with the msp2 mixed alleles (odds ratio (OR):0.13; 95%CI: 0.03–0.53). Mixed msp1 of K1 + RO33 was associated with severe malaria (OR: 28.50; 95%CI: 1.59–1532.30). Conclusion This study found a strong association between severe malaria in Aceh with subjects carrying the msp1 mixed alleles of K1 and RO33. The liver function abnormal value associated with the msp2 mixed allelic subfamilies. Further study in different geographic areas is recommended.

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