Ha. Giha et al., Overlapping antigenic repertoires of variant antigens expressed on the surface of erythrocytes infected by Plasmodium falciparum, PARASITOL, 119, 1999, pp. 7-17
Antibodies against variable antigens expressed on the surface of Plasmodium
falciparum-infected erythrocytes are believed to be important for protecti
on against malaria. A target for these antibodies is the P. falciparum eryt
hrocyte membrane protein 1, PfEMP1, which is encoded by around 50 var genes
and undergoes clonal variation. Using agglutination and mixed agglutinatio
n tests and flow cytometry to analyse the recognition of variant antigens o
n parasitized erythrocytes by plasma antibodies from individuals living in
Daraweesh in eastern Sudan, an area of seasonal and unstable malaria transm
ission, we show that these antibodies recognize different variant antigens
expressed by parasites of different genotype. Comparing the levels and acqu
isition of antibody to variant antigens in pairs of parasite isolates expre
ssing different variant types, there is a correlation between the acquisiti
on of antibodies to some combinations of variant antigens but not to others
. These results indicate that (1) a single infection will induce the produc
tion of antibodies recognizing several variants of surface-expressed antige
ns, (2) the repertoire of variable antigens expressed by different parasite
s is overlapping and the degree of overlap differs between isolates, and (3
) the expression of at least some variant antigens is genetically linked.