Specific antibody-dependent cellular cytotoxicity in human malaria

A micromethod for the study of specific antibody-dependent cellular cytotoxicity (ADCC) in human malaria is described, using cultured, asexual Plasmodium falciparum parasites as viable target cells. Lymphocytes from children with acute malaria, uninfected immune adult Gambians and adult Gambians infected with P. falciparum were capable of killing P. falciparum in vitro in the presence of malaria antibody. A parasite growth-promoting factor, produced by lymphocytes in non-immune serum and at a lymphocyte--parasite ratio of 10:1, in immune serum, was found to produce three-fold increases in growth of P. falciparum. The mechanisms by which ADCC may occur are also discussed.