Antigens Induced on Erythrocytes by <i>P. falciparum</i> : Expression of Diverse and Conserved Determinants

TLDR

In malaria, Plasmodium falciparum–infected red blood cells display new antigens, including conserved determinants that may be key to natural or vaccine‑induced immunity. In a study of these antigens in the erythrocytes of naturally infected children in the Gambia, an antibody‑mediated agglutination assay revealed an extreme degree of antigenic diversity. Serum from each of ten convalescent Gambian children reacted with their own infected erythrocytes but not with those of other children, whereas adult Gambian sera reacted broadly with all children’s infected cells, indicating shared determinants recognized by antibodies.

Abstract

Red blood cells that are infected with the malaria parasite Plasmodium falciparum express new antigens on their surface. In a study of these antigens in the erythrocytes of naturally infected children in the Gambia, an antibody-mediated agglutination assay revealed an extreme degree of antigenic diversity. Serum samples from each of ten children in the convalescent stage of malaria infection reacted with infected cells from the same child but generally not with infected cells from the other children. The Gambian children's erythrocytes also expressed shared determinants: sera from Gambian adults often reacted with the surface of infected cells from all of the children and were shown by adsorption and elution experiments to contain antibodies that recognized several isolates. Conserved determinants exposed on infected erythrocytes may be important for development of antimalarial immunity either naturally or through vaccination.