CROSSREACTIVITY WITH SPOROZOITES, EXOERYTHROCYTIC FORMS AND BLOOD SCHIZONTS OF PLASMODIUM-BERGHEI IN INDIRECT FLUORESCENT-ANTIBODY TESTS WITH SERA OF RATS IMMUNIZED WITH SPOROZOITES OR INFECTED BLOOD

  • 1 January 1977
    • journal article
    • research article
    • Vol. 29  (1) , 43-51
Abstract
IFA [indirect fluorescent antibody] studies are reported using plasmodial antigens from 3 different stages of the life cycle of P. berghei: sporozoites (SP); exoerythrocytic schizonts in rat liver (EEF); and parasitized rat erythrocytes (SCH; schizonts). Two series of specific sera were applied: sera from adults rats with a blood-induced infection (series A) and sera from rats immunized against SP by mosquito bites and protected against parasitemia by chloroquine (series B). In series A antibody titers with all 3 antigens were seen, but those with SCH were generally the highest. Superinfection with parasitized rat blood did not change the titer. In series B sera, collected from rats after a single exposure to infected mosquitoes, showed only titers with SP from day 3 onwards, but after a 2nd exposure titers to all 3 antigens developed. Crossreactivity with the heterologous antigens in series B was clearly less than in series A. Anti-P. berghei SP antibodies did not crossreact with P. vivax SP. Rats of series A were resistant to a challenge of parasitized blood and could inhibit the development of SP. Rats of series B were protected against a challenge of SP but not of infected blood. Results are discussed.