scholarly journals Small Variant STEVOR Antigen Is Uniquely Located within Maurer's Clefts in Plasmodium falciparum-Infected Red Blood Cells

2002 ◽  
Vol 1 (6) ◽  
pp. 926-935 ◽  
Author(s):  
M. Kaviratne ◽  
S. M. Khan ◽  
W. Jarra ◽  
P. R. Preiser
Keyword(s):  
Plasmodium Falciparum ◽  
Multigene Family ◽  
Infected Erythrocyte ◽  
Asexual Parasite ◽  
Parasite Life Cycle ◽  
Host Parasite Interactions ◽  
Erythrocyte Surface ◽  
Maurer's Clefts ◽  
Host Parasite ◽  
Parasite Populations

ABSTRACT Malaria parasite antigens encoded by multigene families are important factors in virulence and in disease pathology. In Plasmodium falciparum, the virulence factor PfEMP-1 is encoded by the var multigene family and is exposed at the infected erythrocyte surface. PfEMP-1 is clonally variant, allowing the parasite to evade host immunity. The recently identified P. falciparum stevor multigene family and its products also have the potential to be involved in similar important aspects of host-parasite interactions. Here, we show tightly regulated stage-specific transcription of stevor occurring over just a few hours of the asexual parasite life cycle. Only a subset of stevor genes are transcribed in parasite populations maintained in cultures and in single micromanipulated parasites. Antibodies against STEVOR recognize proteins of the expected size (∼37 kDa) and localize STEVOR in Maurer's clefts, unique membranous structures located in the cytoplasm of infected erythrocytes. The fact that the timing of stevor expression and the location of STEVOR are clearly distinct from those of other parasite variant antigens suggests that this gene family may have a novel role in P. falciparum biology.

scholarly journals Plasmodium falciparum STEVOR Proteins Are Highly Expressed in Patient Isolates and Located in the Surface Membranes of Infected Red Blood Cells and the Apical Tips of Merozoites

2008 ◽  
Vol 76 (7) ◽  
pp. 3329-3336 ◽  
Author(s):  
Jane E. Blythe ◽  
Xue Yan Yam ◽  
Claudia Kuss ◽  
Zbynek Bozdech ◽  
Anthony A. Holder ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Multigene Family ◽  
Blood Cells ◽  
Antigenic Variation ◽  
Human Parasite ◽  
Host Parasite Interactions ◽  
Maurer's Clefts ◽  
Host Parasite ◽  
Family Code

ABSTRACT The human parasite Plasmodium falciparum has the potential to express a vast repertoire of variant proteins on the surface of the infected red blood cell (iRBC). Variation in the expression pattern of these proteins is linked to antigenic variation and thereby evasion of host antibody-mediated immunity. The genes in the stevor multigene family code for small variant antigens that are expressed in blood-stage parasites where they can be detected in membranous structures called Maurer's clefts (MC). Some studies have indicated that STEVOR protein may also be trafficked to the iRBC membrane. To address the location of STEVOR protein in more detail, we have analyzed expression in several cultured parasite lines and in parasites obtained directly from patients. We detected STEVOR expression in a higher proportion of parasites recently isolated from patients than in cultured parasite lines and show that STEVOR is trafficked in schizont-stage parasites from the MC to the RBC cytosol and the iRBC membrane. Furthermore, STEVOR protein is also detected at the apical end of merozoites. Importantly, we show that culture-adapted parasites do not require STEVOR for survival. These findings provide new insights into the role of the stevor multigene family during both the schizont and merozoite stages of the parasite and highlight the importance of studying freshly isolated parasites, rather than parasite lines maintained in culture, when investigating potential mediators of host-parasite interactions.

scholarly journals Trafficking and Association of Plasmodium falciparum MC-2TM with the Maurer’s Clefts

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 431
Author(s):  
Raghavendra Yadavalli ◽  
John W. Peterson ◽  
Judith A. Drazba ◽  
Tobili Y. Sam-Yellowe
Keyword(s):  
Plasmodium Falciparum ◽  
Erythrocyte Membrane ◽  
Sodium Carbonate ◽  
Infected Erythrocyte ◽  
Brefeldin A ◽  
Specific Expression ◽  
Lipid Interactions ◽  
And Topology ◽  
Streptolysin O ◽  
Maurer's Clefts

In this study, we investigated stage specific expression, trafficking, solubility and topology of endogenous PfMC-2TM in P. falciparum (3D7) infected erythrocytes. Following Brefeldin A (BFA) treatment of parasites, PfMC-2TM traffic was evaluated using immunofluorescence with antibodies reactive with PfMC-2TM. PfMC-2TM is sensitive to BFA treatment and permeabilization of infected erythrocytes with streptolysin O (SLO) and saponin, showed that the N and C-termini of PfMC-2TM are exposed to the erythrocyte cytoplasm with the central portion of the protein protected in the MC membranes. PfMC-2TM was expressed as early as 4 h post invasion (hpi), was tightly colocalized with REX-1 and trafficked to the erythrocyte membrane without a change in solubility. PfMC-2TM associated with the MC and infected erythrocyte membrane and was resistant to extraction with alkaline sodium carbonate, suggestive of protein-lipid interactions with membranes of the MC and erythrocyte. PfMC-2TM is an additional marker of the nascent MCs.

Expression of the RESA gene in Plasmodium falciparum isolate FCR3 is prevented by a subtelomeric deletion

1989 ◽  
Vol 9 (8) ◽  
pp. 3584-3587
Author(s):  
R Cappai ◽  
M R van Schravendijk ◽  
R F Anders ◽  
M G Peterson ◽  
L M Thomas ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Antigen ◽  
Infected Erythrocyte ◽  
Falciparum Isolate ◽  
Erythrocyte Surface ◽  
Subtelomeric Deletion

We show here that the Plasmodium falciparum isolate FCR3 does not express the ring-infected erythrocyte surface antigen (RESA). This is because the 5' end of the RESA gene has been inverted and partly deleted and a telomere has been added to it. We propose a model to explain these events.

A and T homopolymeric stretches mediate a DNA inversion in Plasmodium falciparum which results in loss of gene expression

1990 ◽  
Vol 10 (6) ◽  
pp. 3243-3246
Author(s):  
L G Pologe ◽  
D de Bruin ◽  
J V Ravetch
Keyword(s):  
Gene Expression ◽  
Plasmodium Falciparum ◽  
Gene Structure ◽  
Infected Erythrocyte ◽  
Dna Rearrangement ◽  
Coding Sequences ◽  
Dna Inversion ◽  
Erythrocyte Surface ◽  
Stable Substrate ◽  
Flanking Sequences

Ring-infected erythrocyte surface antigen-negative isolates of Plasmodium falciparum demonstrate a complex DNA rearrangement with inversion of 5' coding sequences, deletion of upstream and flanking sequences, and healing of the truncated chromosome by telomere addition. An inversion intermediate that results in the telomeric gene structure for RESA has been identified in the pathway. This inversion creates a mitotically stable substrate for the sequence-specific addition of telomere repeats at the deletion breakpoint.

scholarly journals A and T homopolymeric stretches mediate a DNA inversion in Plasmodium falciparum which results in loss of gene expression.

1990 ◽  
Vol 10 (6) ◽  
pp. 3243-3246 ◽  
Author(s):  
L G Pologe ◽  
D de Bruin ◽  
J V Ravetch
Keyword(s):  
Gene Expression ◽  
Plasmodium Falciparum ◽  
Gene Structure ◽  
Infected Erythrocyte ◽  
Dna Rearrangement ◽  
Coding Sequences ◽  
Dna Inversion ◽  
Erythrocyte Surface ◽  
Stable Substrate ◽  
Flanking Sequences

Ring-infected erythrocyte surface antigen-negative isolates of Plasmodium falciparum demonstrate a complex DNA rearrangement with inversion of 5' coding sequences, deletion of upstream and flanking sequences, and healing of the truncated chromosome by telomere addition. An inversion intermediate that results in the telomeric gene structure for RESA has been identified in the pathway. This inversion creates a mitotically stable substrate for the sequence-specific addition of telomere repeats at the deletion breakpoint.

scholarly journals Sex-based differences in clearance of chronic Plasmodium falciparum infection

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jessica Briggs ◽  
Noam Teyssier ◽  
Joaniter I Nankabirwa ◽  
John Rek ◽  
Prasanna Jagannathan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Host Response ◽  
Behavioral Risk ◽  
Biological Sex ◽  
Force Of Infection ◽  
Host Parasite Interactions ◽  
Infection Event ◽  
Asymptomatic Infections ◽  
Host Parasite ◽  
Eastern Uganda

Multiple studies have reported a male bias in incidence and/or prevalence of malaria infection in males compared to females. To test the hypothesis that sex-based differences in host-parasite interactions affect the epidemiology of malaria, we intensively followed Plasmodium falciparum infections in a cohort in a malaria endemic area of eastern Uganda and estimated both force of infection (FOI) and rate of clearance using amplicon deep-sequencing. We found no evidence of differences in behavioral risk factors, incidence of malaria, or FOI by sex. In contrast, females cleared asymptomatic infections at a faster rate than males (hazard ratio [HR]=1.82, 95% CI 1.20 to 2.75 by clone and HR = 2.07, 95% CI 1.24 to 3.47 by infection event) in multivariate models adjusted for age, timing of infection onset, and parasite density. These findings implicate biological sex-based differences as an important factor in the host response to this globally important pathogen.

scholarly journals The ring-infected erythrocyte surface antigen (RESA) of Plasmodium falciparum stabilizes spectrin tetramers and suppresses further invasion

Blood ◽  
2007 ◽  
Vol 110 (3) ◽  
pp. 1036-1042 ◽  
Author(s):  
Xinhong Pei ◽  
Xinhua Guo ◽  
Ross Coppel ◽  
Souvik Bhattacharjee ◽  
Kasturi Haldar ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Antigen ◽  
Infected Erythrocyte ◽  
Host Cell Membrane ◽  
Acid Fragment ◽  
Erythrocyte Surface ◽  
Parasite Plasmodium Falciparum ◽  
Functional Consequences ◽  
Self Association ◽  
Resistance To Invasion

AbstractThe malaria parasite Plasmodium falciparum releases the ring-infected erythrocyte surface antigen (RESA) inside the red cell on entry. The protein migrates to the host cell membrane, where it binds to spectrin, but neither the nature of the interaction nor its functional consequences have previously been defined. Here, we identify the binding motifs involved in the interaction and describe a possible function. We have found that spectrin binds to a 108–amino acid fragment (residues 663-770) of RESA, and that this RESA fragment binds to repeat 16 of the β-chain, close to the labile dimer-dimer self-association site. We further show that the RESA fragment stabilizes the spectrin tetramer against dissociation into its constituent dimers, both in situ and in solution. This is accompanied by enhanced resistance of the cell to both mechanical and thermal degradation. Resealed erythrocytes containing RESA663-770 display resistance to invasion by merozoites of P falciparum. We infer that the evolutionary advantage of RESA to the parasite lies in its ability to prevent invasion of cells that are already host to a developing parasite, as well as possibly to guard the cell against thermal damage at the elevated body temperatures prevailing in febrile crises.

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