The C-Terminal Segment of the Cysteine-Rich Interdomain of Plasmodium falciparum Erythrocyte Membrane Protein 1 Determines CD36 Binding and Elicits Antibodies That Inhibit Adhesion of Parasite-Infected Erythrocytes

摘要

Attachment of erythrocytes infected by Plasmodium falciparum to receptors of the microvasculature is a major contributor to the pathology and morbidity associated with malaria. Adhesion is mediated by the P. falciparum erythrocyte membrane protein 1 (PfEMP-1), which is expressed at the surface of infected erythrocytes and is linked to both antigenic variation and cytoadherence. PfEMP-1 contains multiple adhesive modules, including the Duffy binding-like domain and the cysteine-rich interdomain region (CIDR). The interaction between CIDRα and CD36 promotes stable adherence of parasitized erythrocytes to endothelial cells. Here we show that a segment within the C-terminal region of CIDRα determines CD36 binding specificity. Antibodies raised against this segment can specifically block the adhesion to CD36 of erythrocytes infected with various parasite strains. Thus, small regions of PfEMP-1 that determine binding specificity could form suitable components of an antisequestration malaria vaccine effective against different parasite strains.