PLASMODIUM-FALCIPARUM - CD36 DEPENDENT CYTOADHERENCE OR ROSETTING OF INFECTED ERYTHROCYTES IS MODULATED BY KNOBS

A knobless (K-) line of the FCR-3 isolate of Plasmodium falciparum was obtained by gelatin flotation. Immunofluorescent staining and immunob lots indicated that both the K- line and the K+ (knobby) line from whi ch it was derived contained similar forms of potentially adhesive modi fied band 3 protein. When the K+ and K- lines were assayed for their c ytoadherent and resetting abilities the K+ line showed a high level of CD36 dependent cytoadherence, whereas the K- line demonstrated a mark ed pH dependent increase in resetting. Resetting was inhibited by the addition of peptides based on band 3 motifs, suggesting that cytoadher ence and resetting involve the same adhesin but that the presence of k nobs affects whether the adherent preference of the infected erythrocy te is uninfected red cells or endothelial/C32 amelanotic melanoma cell s.