Analysis of CSA-Binding Parasites and Antiadhesion Antibodies

Unlike other malaria parasites of man, Plasmodium falciparum parasites are able to sequester in postcapillary venules (1 ). This allows mature forms of the parasite to avoid circulating through the spleen, where they could be destroyed. Parasites sequester by adhering to receptors on the endothelial surface; endothelial receptors that support parasite binding in vitro include CD36, thrombospondin, ICAM-1, VCAM-1, ELAM-1, CSA, PECAM-1, the integrin α_v β3, and P-selectin (2 -9 ). Electron-dense protrusions, called knobs, appear on the surface of infected red blood cells (IRBCs) and act as points of contact with the endothelium (10 -11 ). Variant and invariant antigens expressed by the parasite on the surface of IRBCs have been identified as binding ligands (12 -14 ).