Resetting of Plasmodium falciparum required multiple components of the uninfected erythrocytes

The mechanism of rosette formation of uninfected erythrocytes with Plasmodi um falciparum-infected erythrocytes is rarely described. In this study, res etting of uninfected normal erythrocytes with infected erythrocytes signifi cantly reduced after treatment of the uninfected erythrocytes with neuramin idase. In contrast, the resetting property of the infected erythrocytes was abolished by trypsinization but not by neuraminidase. The in vitro resetti ng model showed that uninfected thalassemic erythrocytes poorly formed rose ttes with infected normal erythrocytes when compared with normal erythrocyt es of the same blood group. A resetting parasite clone showed significant r eduction in resetting with thalassemic erythrocytes of all blood groups, ho wever, this reduction was not obvious when the wild P. falciparum isolates were studied. These results suggest that while parasites from a single clon e can rosette with uninfected erythrocytes via carbohydrate component, ther e is more than one type of receptor on uninfected erythrocytes involved in rosette formation with the heterogeneous populations of the wild P. falcipa rum isolates.