scholarly journals An In Vivo and In Vitro Model of Plasmodium falciparum Rosetting and Autoagglutination Mediated by varO, a Group A var Gene Encoding a Frequent Serotype

2008 ◽  
Vol 76 (12) ◽  
pp. 5565-5580 ◽  
Author(s):  
Inès Vigan-Womas ◽  
Micheline Guillotte ◽  
Cécile Le Scanf ◽  
Sébastien Igonet ◽  
Stéphane Petres ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Confidence Interval ◽  
Red Blood Cells ◽  
Blood Cells ◽  
In Vitro Model ◽  
Human Erythrocytes ◽  
Group A ◽  
Vitro Model

ABSTRACTIn theSaimiri sciureusmonkey, erythrocytes infected with the varO antigenic variant of thePlasmodium falciparumPalo Alto 89F5 clone bind uninfected red blood cells (rosetting), form autoagglutinates, and have a high multiplication rate, three phenotypic characteristics that are associated with severe malaria in human patients. We report here that varO parasites express avargene having the characteristics of group Avargenes, and we show that the varO Duffy binding-like 1α1(DBL1α1) domain is implicated in the rosetting of bothS. sciureusand human erythrocytes. The soluble varO N-terminal sequence (NTS)-DBL1α1recombinant domain, produced in a baculovirus-insect cell system, induced high titers of antibodies that reacted with varO-infected red blood cells and disrupted varO rosettes. varO parasites were culture adapted in vitro using human erythrocytes. They formed rosettes and autoagglutinates, and they had the same surface serotype and expressed the samevarOgene as the monkey-propagated parasites. To develop an in vitro model with highly homogeneous varO parasites, rosette purification was combined with positive selection by panning with a varO NTS-DBL1α1-specific mouse monoclonal antibody. The single-variant, clonal parasites were used to analyze seroprevalence for varO at the village level in a setting where malaria is holoendemic (Dielmo, Senegal). We found 93.6% (95% confidence interval, 89.7 to 96.4%) seroprevalence for varO surface-reacting antibodies and 86.7% (95% confidence interval, 82.8 to 91.6%) seroprevalence for the recombinant NTS-DBL1α1domain, and virtually all permanent residents had seroconverted by the age of 5 years. These data imply that the varO model is a relevant in vivo and in vitro model for rosetting and autoagglutination that can be used for rational development of vaccine candidates and therapeutic strategies aimed at preventing malaria pathology.

scholarly journals An In Vivo and In Vitro Model of Plasmodium falciparum Rosetting and Autoagglutination Mediated by varO, a Group A var Gene Encoding a Frequent Serotype

2009 ◽  
Vol 77 (2) ◽  
pp. 926-926
Author(s):  
Inès Vigan-Womas ◽  
Micheline Guillotte ◽  
Cécile Le Scanf ◽  
Sébastien Igonet ◽  
Stéphane Petres ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
In Vitro Model ◽  
Gene Encoding ◽  
Group A ◽  
Vitro Model ◽  
Var Gene

Ultrastructural observations on the in vitro cytoadherence of Plasmodium falciparum infected red blood cells

1990 ◽  
Vol 48 (3) ◽  
pp. 914-915
Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Umbilical Vein ◽  
Cell Types ◽  
Amelanotic Melanoma ◽  
Cytoplasmic Process ◽  
Umbilical Vein Endothelial Cells

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).

An in Vitro Model for Arsine Toxicity Using Isolated Red Blood Cells

1995 ◽  
Vol 25 (2) ◽  
pp. 302-306
Author(s):  
K. M. HATLELID ◽  
C. BRAILSFORD ◽  
D. E. CARTER
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
In Vitro Model ◽  
Vitro Model

scholarly journals Red blood cells as an efficient in vitro model for evaluating the efficacy of metallic nanoparticles

3 Biotech ◽  
2019 ◽  
Vol 9 (7) ◽  
Author(s):  
Ridhima Wadhwa ◽  
Taru Aggarwal ◽  
Noopur Thapliyal ◽  
Ashutosh Kumar ◽  
Priya ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Metallic Nanoparticles ◽  
In Vitro Model ◽  
Vitro Model

scholarly journals THE CULTIVATION OF MALARIAL PLASMODIA (PLASMODIUM VIVAX AND PLASMODIUM FALCIPARUM) IN VITRO

1912 ◽  
Vol 16 (4) ◽  
pp. 567-579 ◽  
Author(s):  
C. C. Bass ◽  
Foster M. Johns
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Plasmodium Vivax ◽  
Blood Cells ◽  
Distinct Species ◽  
Sexual Cycle ◽  
Successive Generations ◽  
Asexual Cycle

The asexual cycle of Plasmodium vivax and Plasmodium falciparum has been cultivated in vitro in human blood. The parasites have been grown also in red blood cells in the presence of Locke's solution, free of calcium chlorid and in the presence of ascitic fluid. The parasites grow within red blood cells and there is no evidence that they can be grown outside of these cells. The parasites are destroyed in a very few minutes in vitro by normal human serum or by all modifications of serum that we have tested. This fact, together with numerous observations of parasites in all stages of growth apparently within red cells, renders untenable the idea of extracorpuscular development. Leucocytes phagocytize and destroy malarial plasmodia growing in vitro only when the parasites escape from their red blood cell capsule or when the latter is perforated or becomes permeable. Successive generations of Plasmodium vivax and Plasmodium falciparum have been cultivated in vitro by removing the leucocytes from the culture and by transplanting to fresh red blood cells and serum at proper intervals. The asexual cycle of Plasmodium vivax and Plasmodium falciparum cultivated in vitro does not differ from the same cycle growing in vivo. The sexual cycle has not been cultivated, though we have obtained some evidence of the possibility of its accomplishment. There can no longer be any doubt that Plasmodium vivax and Plasmodium falciparum are separate and distinct species. When grown in an identical culture medium and under exactly the same conditions they remain distinct. In twenty-nine cultures of æstivo-autumnal parasites many forms and sizes have been observed, so that evidence is supplied of the occurrence of different varieties of ætivo-autumnal malarial plasmodia. The so called tertian ætivo-autumnal variety may be seen at the proper stage in all cultures grown from merozoites. The form and appearance of the same culture of plasmodia may vary greatly under different conditions which are not necessarily destructive to the parasites. Their generation period may vary from thirty hours (ætivo-autumnal) to four days (tertian), as a result of variation in the temperature at which they were cultivated. Sexual parasites grow in the cultures and are more resistant to unfavorable conditions than schizonts, often living several days after the latter die out. Forms suggesting parthenogenesis have been observed.

scholarly journals Quantifying the biophysical characteristics of Plasmodium-falciparum-parasitized red blood cells in microcirculation

2010 ◽  
Vol 108 (1) ◽  
pp. 35-39 ◽  
Author(s):  
D. A. Fedosov ◽  
B. Caswell ◽  
S. Suresh ◽  
G. E. Karniadakis
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Three Dimensional ◽  
Quantitative Agreement ◽  
In Vivo Studies ◽  
Cell Dynamics ◽  
Sudden Transition

The pathogenicity of Plasmodium falciparum (Pf) malaria results from the stiffening of red blood cells (RBCs) and its ability to adhere to endothelial cells (cytoadherence). The dynamics of Pf-parasitized RBCs is studied by three-dimensional mesoscopic simulations of flow in cylindrical capillaries in order to predict the flow resistance enhancement at different parasitemia levels. In addition, the adhesive dynamics of Pf-RBCs is explored for various parameters revealing several types of cell dynamics such as firm adhesion, very slow slipping along the wall, and intermittent flipping. The parasite inside the RBC is modeled explicitly in order to capture phenomena such as “hindered tumbling” motion of the RBC and the sudden transition from firm RBC cytoadherence to flipping on the endothelial surface. These predictions are in quantitative agreement with recent experimental observations, and thus the three-dimensional modeling method presented here provides new capabilities for guiding and interpreting future in vitro and in vivo studies of malaria.

Refractoriness of Callithrix penicillata Red Blood Cells to Plasmodium falciparum In vivo and In vitro

1988 ◽  
Vol 74 (3) ◽  
pp. 514 ◽  
Author(s):  
Eliana M. M. Rocha ◽  
Leogenes H. Pereira ◽  
Virgilio E. do Rosario ◽  
Antoniana U. Krettli
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells
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