Small peripheral-blood lymphocytes from patients partially immune to infections with either the Malayan (Camp.) or Uganda I strain of Plasmodium falciparum underwent transformation to large, ameboid, pyroninophilic blasts when cultured in vitro with extracts of P. falciparum gametocytes or trophozoites. Lymphocytes from uninfected persons did not undergo blastoid transformation when exposed to the same extracts. This phenomenon was demonstrable not only during patent parasitemia but also for as long as 2 years after radical cure of the malaria infection. Polyacrylamide-disc electrophoresis of the gametocyte extracts demonstrated protein bands not present in normal hemolysates.
Present address: Department of Internal Medicine, Simpson Memorial Institute, Univeristy of Michiga, Ann Arbor, Michigan.
Recipient of a Research and Career Development Award from the United States Public Health Service.