Sc. Chaiyaroj et al., MULTIPLE LIGANDS FOR CYTOADHERENCE CAN BE PRESENT SIMULTANEOUSLY ON THE SURFACE OF PLASMODIUM-FALCIPARUM-INFECTED ERYTHROCYTES, Proceedings of the National Academy of Sciences of the United Statesof America, 91(23), 1994, pp. 10805-10808
A major virulence factor of Plasmodium falciparum is the adherence of
parasitized erythrocytes to the wall of postcapillary venules via a sp
ecific interaction between parasite-derived erythrocyte surface ligand
s and receptors on endothelial cells. To study this phenomenon in vitr
o, we selected a parasite population that expressed at least two diffe
rent ligands and demonstrated that parasitized cells may coexpress lig
ands with specificity for multiple receptors. This selected parasite l
ine had several antigenic and cytoadherence characteristics that were
different from those of the parent line. Single parasitized erythrocyt
es were able to adhere to three distinct receptors via at least two se
parate ligands; a trypsin-sensitive molecule mediated cytoadherence to
CD36 and intercellular adhesion molecule 1 and a trypsin-insensitive
molecule(s) was responsible for adherence to a third receptor on the s
urface of melanoma cells. We present evidence that this newly discover
ed receptor for cytoadherence is an N-linked glycosaminoglycan, as tre
atment of melanoma cells with endoglycosidase H abolished cytoadherenc
e. These observations emphasize the adaptability of P. falciparum and
the complexity of the cytoadherence phenomenon.