Erythrocyte destruction and protective immunity to Malaria: enhancement of the immune response by phenylhydrazine treatment.

Malaria infection is characterized by extensive destruction of erythrocytes. In addition, the surface membrane of parasitized erythrocytes becomes biochemically and antigenically modified. Thus during infection the host immune system is exposed to massive amounts of modified erythrocytes on a scale not normally considered in conventional immunological experiments. The haemocytoxic drug phenylhydrazine hydrochloride has been used to mimic, in otherwise normal animals, the effect of the modification and destruction of erythrocytes which occurs in malaria. The experiments demonstrated that protective immunity to Plasmodium berghei KSP11 infection in rats and mice is significantly enhanced by this treatment, that this effect generates memory, can be transferred with spleen cells, and can have both enhancing and suppressive action on the protective immune response.