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 ◽  
...  

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.

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Albert E. Zhou ◽  
Andrea A. Berry ◽  
Jason A. Bailey ◽  
Andrew Pike ◽  
Antoine Dara ◽  
...  

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.


2004 ◽  
Vol 72 (3) ◽  
pp. 1603-1607 ◽  
Author(s):  
Diane Wallace Taylor ◽  
Aniong Zhou ◽  
Lauren E. Marsillio ◽  
Lucy W. Thuita ◽  
Efua B. Leke ◽  
...  

ABSTRACT Plasmodium falciparum-infected erythrocytes often sequester in the placenta of pregnant women, producing placental malaria, a condition that can compromise the health of the developing fetus. Scientists are hopeful that a vaccine can be developed to prevent this condition. Immunological mechanisms responsible for eliminating parasites from the placenta remain unclear, but antibodies to the carboxyl-terminal 19-kDa segment of the merozoite surface protein 1 (MSP1-19), the ring-infected erythrocyte surface antigen (RESA), and an erythrocyte-surface ligand that binds chondroitin sulfate A (CSA-L) have been implicated. In addition, antibodies to sporozoite and liver-stage antigens could reduce initial parasite burdens. This study sought to determine if antibodies to the circumsporozoite protein (CSP), liver-stage antigen 1 (LSA1), RESA, MSP1-19, or CSA-L correlated with either the absence of placental parasites or low placental parasitemias. Using a frequency-matched case-control study design, we compared antibody levels in women (gravidity 1 to 11) with and without placental malaria. Results showed that women who were antibody negative for MSP1-19 were at a higher risk of having placental malaria than women with antibodies (P < 0.007). Furthermore, an association between high levels of antibodies that blocked the binding of infected erythrocytes to CSA and low placental parasitemias was observed (P = 0.02). On the other hand, women with high antibody levels at term to CSP, LSA1, and RESA were more likely to have placental malaria than antibody-negative women. Since antibodies to MSP1-19 and CSA-L were associated with reduced placental malaria, both antigens show promise for inclusion in a vaccine for women of child-bearing age.


mSphere ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Maria del Pilar Quintana

ABSTRACT Maria del Pilar Quintana works on immunology and pathogenesis of severe malaria. In this mSphere of Influence article, she reflects on how the papers “Structural basis for placental malaria mediated by Plasmodium falciparum VAR2CSA” (R. Ma, T. Lian, R. Huang, J. P. Renn, J. D. Petersen, J. Zimmerberg, P. E. Duffy, N. H. Tolia, Nat Microbiol 6:380–391, 2021, https://doi.org/10.1038/s41564-020-00858-9) and “Cryo-EM reveals the architecture of placental malaria VAR2CSA and provides molecular insight into chondroitin sulfate binding” (K. Wang, R. Dagil, T. Lavsten, S. K. Misra, C. B. Spliid, Y. Wang, T. Gustavsson, D. R. Sandoval, E. E. Vidal-Calvo, S. Choudary, M. O. Agerback, K. Lindorff-Larsen, M. A. Nielsen, T. G. Theander, J. S. Sharp, T. M. Clausen, P. Gourdon, A. Salanti [Research Square preprint], 2021, https://doi.org/10.21203/rs.3.rs-121821/v1) shed light on the precise structural details behind Plasmodium falciparum VAR2CSA binding to chondroitin sulfate A (CSA) in the placenta and how these novel insights have changed the way she will approach her work toward the discovery of new broadly cross-reactive/inhibitory antibodies targeting VAR2CSA.


2012 ◽  
Vol 80 (4) ◽  
pp. 1479-1490 ◽  
Author(s):  
Yeung L. Tutterrow ◽  
Marion Avril ◽  
Kavita Singh ◽  
Carole A. Long ◽  
Robert J. Leke ◽  
...  

ABSTRACTPlacental malaria, caused by sequestration ofPlasmodium falciparum-infected erythrocytes in the placenta, is associated with increased risk of maternal morbidity and poor birth outcomes. The parasite antigen VAR2CSA (variant surface antigen 2-chondroitin sulfate A) is expressed on infected erythrocytes and mediates binding to chondroitin sulfate A, initiating inflammation and disrupting homeostasis at the maternal-fetal interface. Although antibodies can prevent sequestration, it is unclear whether parasite clearance is due to antibodies to a single Duffy binding-like (DBL) domain or to an extensive repertoire of antibodies to multiple DBL domains and allelic variants. Accordingly, plasma samples collected longitudinally from pregnant women were screened for naturally acquired antibodies against an extensive panel of VAR2CSA proteins, including 2 to 3 allelic variants for each of 5 different DBL domains. Analyses were performed on plasma samples collected from 3 to 9 months of pregnancy from women living in areas in Cameroon with high and low malaria transmission. The results demonstrate that high antibody levels to multiple VAR2CSA domains, rather than a single domain, were associated with the absence of placental malaria when antibodies were present from early in the second trimester until term. Absence of placental malaria was associated with increasing antibody breadth to different DBL domains and allelic variants in multigravid women. Furthermore, the antibody responses of women in the lower-transmission site had both lower magnitude and lesser breadth than those in the high-transmission site. These data suggest that immunity to placental malaria results from high antibody levels to multiple VAR2CSA domains and allelic variants and that antibody breadth is influenced by malaria transmission intensity.


2003 ◽  
Vol 71 (11) ◽  
pp. 6620-6623 ◽  
Author(s):  
Patrick E. Duffy ◽  
Michal Fried

ABSTRACT Antibodies that inhibit Plasmodium falciparum adhesion to the placental receptor chondroitin sulfate A are associated with a reduced risk of placental malaria, but whether these antibodies lead to improved pregnancy outcomes is unknown. We measured antiadhesion antibody levels in parturient women in western Kenya, where malaria transmission is intense. Secundigravid women with antiadhesion activity in their plasma delivered babies that were on average 398 g heavier (P = 0.019) and 2 weeks more mature (P = 0.002) than babies delivered to secundigravidas without antiadhesion activity. Our findings support the development of antiadhesion vaccines to prevent poor fetal outcomes due to pregnancy malaria.


2002 ◽  
Vol 45 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Aleida Vazquez-Macias ◽  
Perla Martinez-Cruz ◽  
Maria Cristina Castaneda-Patlan ◽  
Christine Scheidig ◽  
Jurg Gysin ◽  
...  

2011 ◽  
Vol 286 (18) ◽  
pp. 15908-15917 ◽  
Author(s):  
Madeleine Dahlbäck ◽  
Lars M. Jørgensen ◽  
Morten A. Nielsen ◽  
Thomas M. Clausen ◽  
Sisse B. Ditlev ◽  
...  

Malaria during pregnancy is a major health problem for African women. The disease is caused by Plasmodium falciparum malaria parasites, which accumulate in the placenta by adhering to chondroitin sulfate A (CSA). The interaction between infected erythrocytes and the placental receptor is mediated by a parasite expressed protein named VAR2CSA. A vaccine protecting pregnant women against placental malaria should induce antibodies inhibiting the interaction between VAR2CSA and CSA. Much effort has been put into defining the part of the 350 kDa VAR2CSA protein that is responsible for binding. It has been shown that full-length recombinant VAR2CSA binds specifically to CSA with high affinity, however to date no sub-fragment of VAR2CSA has been shown to interact with CSA with similar affinity or specificity. In this study, we used a biosensor technology to examine the binding properties of a panel of truncated VAR2CSA proteins. The experiments indicate that the core of the CSA-binding site is situated in three domains, DBL2X-CIDRPAM and a flanking domain, located in the N-terminal part of VAR2CSA. Furthermore, recombinant VAR2CSA subfragments containing this region elicit antibodies with high parasite adhesion blocking activity in animal immunization experiments.


2002 ◽  
Vol 99 (15) ◽  
pp. 10020-10024 ◽  
Author(s):  
B. Gamain ◽  
S. Gratepanche ◽  
L. H. Miller ◽  
D. I. Baruch

2005 ◽  
Vol 1 (3) ◽  
pp. e26 ◽  
Author(s):  
Peter C Bull ◽  
Matthew Berriman ◽  
Sue Kyes ◽  
Michael A Quail ◽  
Neil Hall ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document