Malaria sporozoites, which invade hepatocytes within minutes after transmission by an infected mosquito, are covered with the circumsporozoite (CS) protein, which in all Plasmodium species contains the conserved region II-plus. This region is also found as a cell-adhesive motif in a variety of host proteins like thrombospondin, properdin and the terminal complement components.The CS protein with its region II-plus specifically binds to heparan sulfate proteoglycans (HSPG) on the basolateral surface of hepatocytes in the space of Disse (FIG. 1), to certain basolateral cell membranes and basement membranes of the kidney (FIG. 2) as well as to heparin in the granules of connective tissue mast cells. The distribution of the HSPG receptors for the CS protein was examined by incubation of Lowicryl K4M or LR White sections of liver and kidney tissue with the recombinant CS ligand, whose binding sites were detected with a monoclonal anti-CS antibody and protein A gold.
Heparan sulfate proteoglycans mediate internalization and degradation of beta-VLDL and promote cholesterol accumulation by pigeon macrophages
