Inhibition of adhesion of Plasmodium falciparum-infected erythrocytes by structurally defined hyaluronic acid dodecasaccharides

We recently reported that Plasmodium falciparum-infected erythrocytes (IRBC s) can adhere to hyaluronic acid (HA), which appears to be a receptor, in a ddition to chondroitin sulfate A (CSA), for parasite sequestration in the p lacenta. Further investigations of the nature and specificity of this inter action indicate that HA oligosaccharide fragments competitively inhibit par asite adhesion to immobilized purified HA in a size-dependent manner, with dodecasaccharides being the minimum size for maximum inhibition. Rigorously purified and structurally defined HA dodecasaccharides, free of contaminat ion by CSA or other glycosaminoglycans, effectively inhibited IRBC adhesion to HA but not CSA, providing compelling evidence of a specific interaction between IRBCs and HA.