Plasmodium falciparum field isolates use complement receptor 1 (CR1) as a receptor for invasion of erythrocytes

Abstract

AmajorityofPlasmodiumfalciparumstrainsinvadeerythrocytesthroughinteractionswithsialicacid(SA) on glycophorins. However, we recently reported that complement receptor 1 (CR1) is a SA-independent invasionreceptorofmanylaboratorystrainsofP.falciparum.TodeterminetheroleofCR1inerythrocyte invasion among P. falciparum field isolates, we tested eight isolates obtained from children in Kenya. All the parasites examined were capable of invading in a SA-independent manner, and invasion of neuraminidase-treatederythrocyteswasnearlycompletelyblockedbyanti-CR1andsolubleCR1(sCR1). Inaddition,anti-CR1andsCR1partiallyinhibitedinvasionofintacterythrocytesinamajorityofisolates tested. Sequencing of the hypervariable region of P. falciparum AMA-1 showed considerable diversity among all the isolates. These data demonstrate that CR1 mediates SA-independent erythrocyte invasion in P. falciparum field isolates.