Inhibition of malarial parasite invasion by monoclonal antibodies against
glycophorin A correlates with reduction in red cell membrane deformability
G Pasvol, JA Chasis, N Mohandas, DJ Anstee, MJ Tanner and AH Merry
Nuffield Department of Clinical Medicine, John Radcliffe Hospital,
Headington, Oxford, UK.
The effect of well-characterized monoclonal antibodies to red cell surface
molecules on the invasion of human red cells by the malarial parasites
Plasmodium falciparum and Plasmodium knowlesi was examined. Antibodies to
glycophorin A (GP alpha) inhibit invasion for both parasite species, and
this is highly correlated with the degree to which they decrease red cell
membrane deformability as measured by ektacytometry. This effect on
rigidity and invasion was also seen with monovalent Fab fragments. The
closer the antibody binding site was to the membrane bilayer, the greater
was its effect on inducing membrane rigidity and decreasing parasite
invasion. Antibodies to the Wright determinant in particular were the most
inhibitory. This differential effect of the various antibodies was not
correlated with their binding affinities or the number of sites bound per
cell. Antibodies to surface molecules other than GP alpha were without
effect. A novel mechanism is described whereby monoclonal antibodies and
their Fab fragments directed at determinants on the external surface of red
cells might act to inhibit invasion by malarial parasites by altering
membrane material properties.
Volume 74,
Issue 5,
pp. 1836-1843,
10/01/1989
Copyright © 1989 by The American Society of Hematology
