Anemia and anti-erythrocyte antibodies developed after repeated injections of sonicated preparations of Plasmodium berghei and Babesia rodhaini

Abstract

Anemia developed in mice after repeated injections of sonicated preparations of Plasmodium berghei and Babesia rodhaini. Anti-erythrocyte antibodies were detected in sera by an enzyme-linked immunosorbent assay and their levels rose as anemia developed. Administration of carbon particle suspension to block the mononuclear phagocyte system was effective to inhibit anemia induced by injections of sonicated parasite preparations. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analyses were carried out to examine autoantigens on the surface of the erythrocyte membrane reacting to anti-erythrocyte antibodies. The anti-erythrocyte antibodies from mice injected with the sonicated P. berghei preparations bound specifically to three components of the erythrocyte membrane. The anti-erythrocyte antibodies produced by the sonicated B. rodhaini preparations also reacted with four components, two of which corresponded to those reacting after the injection of the sonicated P. berghei preparations. These results suggest that both P. berghei and B. rodhaini organisms have some materials capable of inducing production of the anti-erythrocyte antibodies which mediate erythrophagocytosis by macrophages of the mononuclear phagocyte system during Plasmodium and Babesia infections.