Identification of aTheileria annulataAntigen Expressed in Multiple Stages of the Parasite Life Cycle

1998 ◽  
Vol 90 (1) ◽  
pp. 110-121 ◽  
Author(s):  
P.A. Knight ◽  
S.W. Williamson ◽  
C.G.D. Brown ◽  
L. Bell-Sakyi ◽  
E. Kirvar ◽  
...  
Keyword(s):  
Life Cycle ◽  
Parasite Life Cycle ◽  
Multiple Stages

scholarly journals Dual Plasmepsin-Targeting Antimalarial Agents Disrupt Multiple Stages of the Malaria Parasite Life Cycle

2020 ◽  
Vol 27 (4) ◽  
pp. 642-658.e12 ◽  
Author(s):  
Paola Favuzza ◽  
Manuel de Lera Ruiz ◽  
Jennifer K. Thompson ◽  
Tony Triglia ◽  
Anna Ngo ◽  
...  
Keyword(s):  
Life Cycle ◽  
Malaria Parasite ◽  
Parasite Life Cycle ◽  
Antimalarial Agents ◽  
Multiple Stages

scholarly journals Supression of Perforin-like Protein pores inhibitPlasmodiummultistage-growth, transmission and erythrocyte senescence

2019 ◽  
Author(s):  
Swati Garg ◽  
Abhishek Shivappagowdar ◽  
Rahul S. Hada ◽  
Rajagopal Ayana ◽  
Chandramohan Bathula ◽  
...  
Keyword(s):  
Life Cycle ◽  
Pore Formation ◽  
Host Cells ◽  
Parasite Development ◽  
Parasite Life Cycle ◽  
Efficient Treatment ◽  
Transmission Blocking ◽  
Multi Stage ◽  
Macpf Domain ◽  
Multiple Stages

AbstractThe pore formingPlasmodiumperforin like proteins (PPLP), expressed in all stages of the parasite life cycle are central drivers for host interactions critical for completion of parasite life cycle and high transmission rates. The high sequence similarity in the central membrane attack complex/ perforin (MACPF) domain and consequent functional overlaps defines them as an attractive target for the development of multi-stage antimalarials. Herein we evaluated the mechanism of pan active function of central, highly conserved region of PPLPs, MACPF domain (PMD) and inhibitory potential of specifically designed anti-PMD chemo. TheE. coliexpressed rPMD interacts with erythrocyte membrane and form pores of ~10.5 nm height and ~24.3 nm diameter leading to haemoglobin release and dextran uptake. The treatment with PMD induced erythrocytes senescence at 48 hours which can account for the physiological effect of disseminated PLPs in loss of circulating erythrocytes inducing anemia during malaria infection. The anti-PMD inhibitors effectively blocked intraerythrocytic growth by suppressing invasion and egress of merozoites and protecting against erythrocyte senescence. Moreover, these inhibitors also blocked the hepatic stage and transmission stage parasite development suggesting multi-stage and transmission-blocking potential of these inhibitors. Additionally, the erythrocyte senescence protective potential of PMD inhibitors can be used to occlude PPLPs mediated severe malarial anemia. Further these inhibitors can be developed with a potential to protect against severity of the disease.Author SummaryMalaria continues to be a major global health threat despite of several exciting improvements in the treatment and prevention of the disease. One of the major concerns in the development of therapy is the emergence of the drug resistance. But for the efficient treatment regime, targeting multiple stages including host and vector would serve as an ideal therapy. Perforin like proteins (PLPs) are eukaryotic pore forming proteins that are highly conserved in the apicomplexan parasites. These play crucial roles in entry and exit of parasites from the host cells and establish infection at multiple stages ofPlasmodium spp.life cycle. Understanding the mechanism of pore formation by smaller, functional, pan-active scaffold of PLPs can serve as a target for development of cross stage protection. Here, using various biochemical, biophysical and pharmacological evidences, we validate the activity and characterize the pore formation of PLPs on erythrocytes. Further, our specifically designed inhibitors could restrict this pore formation and impede the exit/entry of the parasites. Moreover, these inhibitors could also exert multiple stage inhibition and rescue the uninfected erythrocytes from death. Together, this study highlights the mechanism of pore formation by PPLPs and evaluates their potential for the development of pan-active inhibitors to provide both symptomatic and transmission blocking cure for malaria.

The Leishmania promastigote surface antigen 2 complex is differentially expressed during the parasite life cycle

1995 ◽  
Vol 74 (2) ◽  
pp. 189-200 ◽  
Author(s):  
Emanuela Handman ◽  
Amelia H. Osborn ◽  
Fiona Symons ◽  
Rosemary van Driel ◽  
Roberto Cappai
Keyword(s):  
Life Cycle ◽  
Surface Antigen ◽  
Differentially Expressed ◽  
Parasite Life Cycle

scholarly journals Flagellar Motility ofTrypanosoma cruziEpimastigotes

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
G. Ballesteros-Rodea ◽  
M. Santillán ◽  
S. Martínez-Calvillo ◽  
R. Manning-Cela
Keyword(s):  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Quantitative Description ◽  
Flagellar Motility ◽  
Parasite Life Cycle ◽  
Large Variability ◽  
Rotational Angle ◽  
Ciliary Beating ◽  
Parasite Motility ◽  
Parasite Behavior

The hemoflagellateTrypanosoma cruziis the causative agent of American trypanosomiasis. Despite the importance of motility in the parasite life cycle, little is known aboutT. cruzimotility, and there is no quantitative description of its flagellar beating. Using video microscopy and quantitative vectorial analysis of epimastigote trajectories, we find a forward parasite motility defined by tip-to-base symmetrical flagellar beats. This motion is occasionally interrupted by base-to-tip highly asymmetric beats, which represent the ciliary beat of trypanosomatid flagella. The switch between flagellar and ciliary beating facilitates the parasite's reorientation, which produces a large variability of movement and trajectories that results in different distance ranges traveled by the cells. An analysis of the distance, speed, and rotational angle indicates that epimastigote movement is not completely random, and the phenomenon is highly dependent on the parasite behavior and is characterized by directed and tumbling parasite motion as well as their combination, resulting in the alternation of rectilinear and intricate motility paths.

scholarly journals Encounter rate between local populations shapes host selection in complex parasite life cycle

2006 ◽  
Vol 89 (1) ◽  
pp. 99-106 ◽  
Author(s):  
GÉRALDINE LOOT ◽  
YOUNG-SEUK PARK ◽  
SOVAN LEK ◽  
SÉBASTIEN BROSSE
Keyword(s):  
Life Cycle ◽  
Host Selection ◽  
Encounter Rate ◽  
Parasite Life Cycle ◽  
Local Populations

scholarly journals Structural, functional and computational studies of membrane recognition by Plasmodium Perforin-Like Proteins 1 and 2.

2021 ◽  
Author(s):  
Sophie Williams ◽  
Xiulian Yu ◽  
Tao Ni ◽  
Robert Gilbert ◽  
Phillip Stansfeld
Keyword(s):  
Life Cycle ◽  
Lipid Bilayers ◽  
Membrane Binding ◽  
Binding Activity ◽  
Life Cycles ◽  
Site Directed Mutagenesis ◽  
Parasite Life Cycle ◽  
Dynamics Simulations ◽  
Membrane Recognition

Perforin-like proteins (PLPs) play key roles in the mechanisms associated with parasitic disease caused by apicomplexans such as Plasmodium (malaria) and Toxoplasma. The T. gondii PLP1 (TgPLP1) mediates tachyzoite egress from cells, while the five Plasmodium PLPs carry out various roles in the life cycle of the parasite and with respect to the molecular basis of disease. Here we focus on Plasmodium vivax PLP1 and PLP2 (PvPLP1 and PvPLP2) compared to TgPLP1; PvPLP1 is important for invasion of mammalian hosts by the parasite and establishment of a chronic infection, PvPLP2 is important during the symptomatic blood stage of the parasite life cycle. Determination of the crystal structure of the membrane-binding APCβ domain of PvPLP1 reveals notable differences with that of TgPLP1, which are reflected in its inability to bind lipid bilayers in the way that TgPLP1 and PvPLP2 can be shown to. Molecular dynamics simulations combined with site-directed mutagenesis and functional assays allow a dissection of the binding interactions of TgPLP1 and PvPLP2 on lipid bilayers, and reveal a similar tropism for lipids found enriched in the inner leaflet of the mammalian plasma membrane. In addition to this shared mode of membrane binding PvPLP2 displays a secondary synergistic interaction side-on from its principal bilayer interface. This study underlines the substantial differences between the biophysical properties of the APCβ domains of Apicomplexan PLPs, which reflect their significant sequence diversity. Such differences will be important factors in determining the cell targeting and membrane-binding activity of the different proteins, in their different developmental roles within parasite life cycles.

scholarly journals Furuncular Botfly Myiasis – A Case Report

2018 ◽  
Vol 10 (1) ◽  
pp. 9-11
Author(s):  
Juliana Gao ◽  
Vera Tešić ◽  
Vesna Petronić Rosić
Keyword(s):  
Case Report ◽  
Life Cycle ◽  
South America ◽  
Treatment Options ◽  
Local Population ◽  
Body Cavity ◽  
Parasite Life Cycle ◽  
Susceptible Host ◽  
Dermatobia Hominis ◽  
Blood Sucking

Abstract Botfly myiasis is an infestation of the skin or a body cavity by developing larvae of Dermatobia hominis, one of the most common flies that cause human infestation among the local population, in regions ranging from Mexico into South America and in travelers. The life cycle starts when a female fly glues the eggs to the vector, a blood-sucking arthropod, which carries the unhatched larvae to the susceptible host. A case of furuncular botfly myiasis in an 85 year-old female with recent travel to Belize is presented here to highlight the parasite life cycle and review the different treatment options.

scholarly journals The Malaria Parasite Cyclic GMP-Dependent Protein Kinase Plays a Central Role in Blood-Stage Schizogony

2009 ◽  
Vol 9 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Helen M. Taylor ◽  
Louisa McRobert ◽  
Munira Grainger ◽  
Audrey Sicard ◽  
Anton R. Dluzewski ◽  
...  
Keyword(s):  
Life Cycle ◽  
Protein Kinase ◽  
Cyclic Gmp ◽  
Malaria Parasite ◽  
Kinase Inhibitor ◽  
Blood Stage ◽  
Parasite Life Cycle ◽  
Dependent Protein Kinase ◽  
Asexual Blood Stage ◽  
Dependent Protein

ABSTRACT A role for the Plasmodium falciparum cyclic GMP (cGMP)-dependent protein kinase (PfPKG) in gametogenesis in the malaria parasite was elucidated previously. In the present study we examined the role of PfPKG in the asexual blood-stage of the parasite life cycle, the stage that causes malaria pathology. A specific PKG inhibitor (compound 1, a trisubstituted pyrrole) prevented the progression of P. falciparum schizonts through to ring stages in erythrocyte invasion assays. Addition of compound 1 to ring-stage parasites allowed normal development up to 30 h postinvasion, and segmented schizonts were able to form. However, synchronized schizonts treated with compound 1 for ≥6 h became large and dysmorphic and were unable to rupture or liberate merozoites. To conclusively demonstrate that the effect of compound 1 on schizogony was due to its selective action on PfPKG, we utilized genetically manipulated P. falciparum parasites expressing a compound 1-insensitive PfPKG. The mutant parasites were able to complete schizogony in the presence of compound 1 but not in the presence of the broad-spectrum protein kinase inhibitor staurosporine. This shows that PfPKG is the primary target of compound 1 during schizogony and provides direct evidence of a role for PfPKG in this process. Discovery of essential roles for the P. falciparum PKG in both asexual and sexual development demonstrates that cGMP signaling is a key regulator of both of these crucial life cycle phases and defines this molecule as an exciting potential drug target for both therapeutic and transmission blocking action against malaria.

scholarly journals Altered parasite life-cycle processes characterize Babesia divergens infection in human sickle cell anemia

Haematologica ◽  
2019 ◽  
Vol 104 (11) ◽  
pp. 2189-2199 ◽  
Author(s):  
Jeny R. Cursino-Santos ◽  
Manpreet Singh ◽  
Eric Senaldi ◽  
Deepa Manwani ◽  
Karina Yazdanbakhsh ◽  
...  
Keyword(s):  
Life Cycle ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Parasite Life Cycle ◽  
Babesia Divergens
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