A role for carbohydrate moieties in the immune response to malaria

Treatment of antigen prepared from asexual blood stages of the human malarial parasite Plasmodium falciparum with a mixture of glycosidases resulted in a reduction in the ability of the antigen to bind antibodies from immune human and monkey sera in an ELISA assay. Some of the epitopes in the parasite material were heat stable, protease resistant, and sensitive to glycosidases. Proteins of Mr 110,000 and 65,000 from parasitized RBC were shown to have reduced antigenicity in Western blots after glycosidase treatment. The carbohydrate side chains of parasite glycoproteins therefore make a contribution to the total antigenicity of the parasite.