scholarly journals Evolutionary structure ofPlasmodium falciparummajor variant surface antigen genes in South America: Implications for epidemic transmission and surveillance

2017 ◽  
Vol 7 (22) ◽  
pp. 9376-9390 ◽  
Author(s):  
Virginie Rougeron ◽  
Kathryn E. Tiedje ◽  
Donald S. Chen ◽  
Thomas S. Rask ◽  
Dionicia Gamboa ◽  
...  
Keyword(s):  
South America ◽  
Surface Antigen ◽  
Variant Surface Antigen

scholarly journals Plasmodium falciparum Variant Surface Antigen Expression Patterns during Malaria

2005 ◽  
Vol 1 (3) ◽  
pp. e26 ◽  
Author(s):  
Peter C Bull ◽  
Matthew Berriman ◽  
Sue Kyes ◽  
Michael A Quail ◽  
Neil Hall ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Antigen ◽  
Expression Patterns ◽  
Antigen Expression ◽  
Variant Surface Antigen ◽  
Surface Antigen Expression

scholarly journals Antibodies to Peptides in Semiconserved Domains of RIFINs and STEVORs Correlate with Malaria Exposure

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Albert E. Zhou ◽  
Andrea A. Berry ◽  
Jason A. Bailey ◽  
Andrew Pike ◽  
Antoine Dara ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Severe Malaria ◽  
Surface Antigen ◽  
Immune Evasion ◽  
Clinical Malaria ◽  
Malaria Episode ◽  
Natural Immunity ◽  
Content Type ◽  
Variant Surface Antigen ◽  
Malaria Exposure

ABSTRACT The repetitive interspersed family (RIFIN) and the subtelomeric variable open reading frame (STEVOR) family represent two of three major Plasmodium falciparum variant surface antigen families involved in malaria pathogenesis and immune evasion and are potential targets in the development of natural immunity. Protein and peptide microarrays populated with RIFINs and STEVORs associated with severe malaria vulnerability in Malian children were probed with adult and pediatric sera to identify epitopes that reflect malaria exposure. Adult sera recognized and reacted with greater intensity to all STEVOR proteins than pediatric sera did. Serorecognition of and seroreactivity to peptides within the semiconserved domain of STEVORs increased with age and seasonal malaria exposure, while serorecognition and seroreactivity increased for the semiconserved and second hypervariable domains of RIFINs only with age. Serologic responses to RIFIN and STEVOR peptides within the semiconserved domains may play a role in natural immunity to severe malaria. IMPORTANCE Malaria, an infectious disease caused by the parasite Plasmodium falciparum, causes nearly 435,000 deaths annually worldwide. RIFINs and STEVORs are two variant surface antigen families that are involved in malaria pathogenesis and immune evasion. Recent work has shown that a lack of humoral immunity to these proteins is associated with severe malaria vulnerability in Malian children. This is the first study to have compared serologic responses of children and adults to RIFINs and STEVORs in settings of malaria endemicity and to examine such serologic responses before and after a clinical malaria episode. Using microarrays, we determined that the semiconserved domains in these two parasite variant surface antigen families harbor peptides whose seroreactivity reflects malaria exposure. A similar approach has the potential to illuminate the role of variant surface antigens in the development of natural immunity to clinical malaria. Potential vaccines for severe malaria should include consideration of peptides within the semiconserved domains of RIFINs and STEVORs.

scholarly journals Evolutionary analyses of the major variant surface antigen-encoding genes reveal population structure of Plasmodium falciparum within and between continents

PLoS Genetics ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. e1009269
Author(s):  
Gerry Tonkin-Hill ◽  
Shazia Ruybal-Pesántez ◽  
Kathryn E. Tiedje ◽  
Virginie Rougeron ◽  
Michael F. Duffy ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Population Structure ◽  
Surface Antigen ◽  
Local Population ◽  
Biological Significance ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Malaria Surveillance ◽  
Geographic Population ◽  
Variant Surface Antigen

Malaria remains a major public health problem in many countries. Unlike influenza and HIV, where diversity in immunodominant surface antigens is understood geographically to inform disease surveillance, relatively little is known about the global population structure of PfEMP1, the major variant surface antigen of the malaria parasite Plasmodium falciparum. The complexity of the var multigene family that encodes PfEMP1 and that diversifies by recombination, has so far precluded its use in malaria surveillance. Recent studies have demonstrated that cost-effective deep sequencing of the region of var genes encoding the PfEMP1 DBLα domain and subsequent classification of within host sequences at 96% identity to define unique DBLα types, can reveal structure and strain dynamics within countries. However, to date there has not been a comprehensive comparison of these DBLα types between countries. By leveraging a bioinformatic approach (jumping hidden Markov model) designed specifically for the analysis of recombination within var genes and applying it to a dataset of DBLα types from 10 countries, we are able to describe population structure of DBLα types at the global scale. The sensitivity of the approach allows for the comparison of the global dataset to ape samples of Plasmodium Laverania species. Our analyses show that the evolution of the parasite population emerging out of Africa underlies current patterns of DBLα type diversity. Most importantly, we can distinguish geographic population structure within Africa between Gabon and Ghana in West Africa and Uganda in East Africa. Our evolutionary findings have translational implications in the context of globalization. Firstly, DBLα type diversity can provide a simple diagnostic framework for geographic surveillance of the rapidly evolving transmission dynamics of P. falciparum. It can also inform efforts to understand the presence or absence of global, regional and local population immunity to major surface antigen variants. Additionally, we identify a number of highly conserved DBLα types that are present globally that may be of biological significance and warrant further characterization.

scholarly journals Antibodies to Escherichia coli-Expressed C-Terminal Domains of Plasmodium falciparum Variant Surface Antigen 2-Chondroitin Sulfate A (VAR2CSA) Inhibit Binding of CSA-Adherent Parasites to Placental Tissue

2013 ◽  
Vol 81 (4) ◽  
pp. 1031-1039 ◽  
Author(s):  
Tracy Saveria ◽  
Andrew V. Oleinikov ◽  
Kathryn Wiliamson ◽  
Richa Chaturvedi ◽  
Joe Lograsso ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Plasmodium Falciparum ◽  
Chondroitin Sulfate ◽  
Surface Antigen ◽  
Transmembrane Protein ◽  
Placental Malaria ◽  
Placental Tissue ◽  
Content Type ◽  
Variant Surface Antigen ◽  
Chondroitin Sulfate A

ABSTRACTPlacental malaria (PM) is characterized by infected erythrocytes (IEs) that selectively bind to chondroitin sulfate A (CSA) and sequester in placental tissue. Variant surface antigen 2-CSA (VAR2CSA), aPlasmodium falciparumerythrocyte membrane protein 1 (PfEMP1) protein family member, is expressed on the surface of placental IEs and mediates adherence to CSA on the surface of syncytiotrophoblasts. This transmembrane protein contains 6 Duffy binding-like (DBL) domains which might contribute to the specific adhesive properties of IEs. Here, we use laboratory isolate 3D7 VAR2CSA DBL domains expressed inEscherichia colito generate antibodies specific for this protein. Flow cytometry results showed that antibodies generated against DBL4ε, DBL5ε, DBL6ε, and tandem double domains of DBL4-DBL5 and DBL5-DBL6 all bind to placental parasite isolates and to lab strains selected for CSA binding but do not bind to children's parasites. Antisera to DBL4ε and to DBL5ε inhibit maternal IE binding to placental tissue in a manner comparable to that for plasma collected from multigravid women. These antibodies also inhibit binding to CSA of several field isolates derived from pregnant women, while antibodies to double domains do not enhance the functional immune response. These data support DBL4ε and DBL5ε as vaccine candidates for pregnancy malaria and demonstrate thatE. coliis a feasible tool for the large-scale manufacture of a vaccine based on these VAR2CSA domains.

scholarly journals In Vitro Variant Surface Antigen Expression in Plasmodium falciparum Parasites from a Semi-Immune Individual Is Not Correlated with Var Gene Transcription

PLoS ONE ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. e0166135 ◽  
Author(s):  
Ellen Inga Bruske ◽  
Sandra Dimonte ◽  
Corinna Enderes ◽  
Serena Tschan ◽  
Matthias Flötenmeyer ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Gene Transcription ◽  
Surface Antigen ◽  
Antigen Expression ◽  
Variant Surface Antigen ◽  
Surface Antigen Expression ◽  
Var Gene ◽  
Immune Individual

Plasmodium falciparum complicated malaria: Modulation and connectivity between exportome and variant surface antigen gene families

2015 ◽  
Vol 201 (1) ◽  
pp. 31-46 ◽  
Author(s):  
Amit Kumar Subudhi ◽  
P.A. Boopathi ◽  
Isha Pandey ◽  
Ramandeep Kohli ◽  
Rohan Karwa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Antigen ◽  
Gene Families ◽  
Antigen Gene ◽  
Complicated Malaria ◽  
Variant Surface Antigen

Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria

The Lancet ◽  
2004 ◽  
Vol 363 (9405) ◽  
pp. 283-289 ◽  
Author(s):  
Trine Staalsoe ◽  
Caroline E Shulman ◽  
Judith N Bulmer ◽  
Ken Kawuondo ◽  
Kevin Marsh ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Falciparum Malaria ◽  
Surface Antigen ◽  
Plasmodium Falciparum Malaria ◽  
Variant Surface Antigen ◽  
Clinical Consequences ◽  
Specific Igg

Isolation and characterization of polysomes from Trypanosoma brucei

Parasitology ◽  
1980 ◽  
Vol 81 (3) ◽  
pp. 537-552 ◽  
Author(s):  
J. S. Cordingley ◽  
M. J. Turner
Keyword(s):  
Protein Synthesis ◽  
Trypanosoma Brucei ◽  
Surface Antigen ◽  
Isolation And Characterization ◽  
Variant Surface Antigen ◽  
26S Rrna

SUMMARYThe isolation of polysomes in bulk from bloodstream forms of Trypanosoma brucei is described. The polysomes are active in in vitro protein synthesis in the presence or absence of initiation inhibitors. Nascent variant surface antigen (VSA) has been detected on these polysomes using purified radio-iodinated antibody. EDTA-induced ribosomal sub-units and their large rRNA's are characterized. The 26S rRNA is nicked to produce 2 molecules which are both smaller than the 195 rRNA of the small sub-unit which is larger than that found in the majority of eukaryotic small sub-units.

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