Studies on the biochemical basis of the interaction of the merozoites of Plasmodium falciparum and the human red cell.

The red cell membrane appears to possess receptors for malarial parasites which are species specific. Plasmodium falciparum invades red cells that have the surface sialoglycoproteins, glycophorins A, B and C. Several regions of these molecules are critical to parasite binding. Invasion of red cells by merozoites can be blocked by both antibodies directed to specific sites on glycophorin and tryptic fragments of these molecules. The parasites appear to bind to the red cells in a lectin-like fashion, since three monosaccharides, namely N-acetyl-glucosamine (Glu NAc), N-acetyl-galactosamine (Gal NAc) and N-acetyl-neuraminic acid (Neu NAc), can specifically block parasite invasion in vitro. Neoglycoproteins made by coupling these sugars to BSA are particularly effective. Possible mechanisms of parasite attachment to and invasion of red cells are discussed.