SWITCHES IN EXPRESSION OF PLASMODIUM-FALCIPARUM VAR GENES CORRELATE WITH CHANGES IN ANTIGENIC AND CYTOADHERENT PHENOTYPES OF INFESTED ERYTHROCYTES

Plasmodium falciparum expresses on the host erythrocyte surface clonal ly variant antigens and ligands that mediate adherence to endothelial receptors. Both are central to pathogenesis, since they allow chronici ty of infection and lead to concentration of infected erythrocytes in cerebral vessels. Here we show that expression of variant antigenic de terminants is correlated with expression of individual members of a la rge, multigene family named var. Each var gene contains copies of a mo tif that has been previously shown to bind diverse host receptors; exp ression of a specific var gene correlated with binding to ICAM-1. Thus , our findings are consistent with the involvement of var genes in ant igenic variation and binding to endothelium.