Journal article
Epitope mapping and topographic analysis of VAR2CSA DBL3X involved in P-falciparum placental sequestration
Pregnancy-associated malaria is a major health problem, which mainly affects primigravidae living in malaria endemic areas. The syndrome is precipitated by accumulation of infected erythrocytes in placental tissue through an interaction between chondroitin sulphate A on syncytiotrophoblasts and a parasite-encoded protein on the surface of infected erythrocytes, believed to be VAR2CSA.
VAR2CSA is a polymorphic protein of approximately 3,000 amino acids forming six Duffy-binding-like (DBL) domains. For vaccine development it is important to define the antigenic targets for protective antibodies and to characterize the consequences of sequence variation. In this study, we used a combination of in silico tools, peptide arrays, and structural modeling to show that sequence variation mainly occurs in regions under strong diversifying selection, predicted to form flexible loops.
These regions are the main targets of naturally acquired immunoglobulin gamma and accessible for antibodies reacting with native VAR2CSA on infected erythrocytes. Interestingly, surface reactive anti-VAR2CSA antibodies also target a conserved DBL3X region predicted to form an alpha-helix. Finally, we could identify DBL3X sequence motifs that were more likely to occur in parasites isolated from primi- and multigravidae, respectively.
These findings strengthen the vaccine candidacy of VAR2CSA and will be important for choosing epitopes and variants of DBL3X to be included in a vaccine protecting women against pregnancy-associated malaria.
Language: | English |
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Publisher: | Public Library of Science |
Year: | 2006 |
Pages: | 1069-1082 |
ISSN: | 15537374 and 15537366 |
Types: | Journal article |
DOI: | 10.1371/journal.ppat.0020124 |
ORCIDs: | 0000-0003-2668-4992 , 0000-0002-1698-4927 , 0000-0002-3509-7514 , 0000-0003-2207-5575 , Lund, Ole and Pedersen, Anders Gorm |
Amino Acid Motifs Amino Acid Sequence Animals Antibodies, Protozoan Antigens, Protozoan B-Lymphocytes Binding, Competitive Biology (General) Chondroitin Sulfates Duffy antigen binding protein, Plasmodium Epitope Mapping Female Genetic Variation Humans Immunologic diseases. Allergy Malaria, Falciparum Models, Molecular Molecular Sequence Data Molecular Structure Parity Placenta Plasmodium falciparum Pregnancy Protein Structure, Tertiary Protozoan Proteins QH301-705.5 RC581-607 Receptors, Cell Surface Recombinant Proteins Recombination, Genetic VAR2CSA protein, Plasmodium falciparum erythrocyte-binding antigen 175, Plasmodium