Cell-mediated cytotoxicity to Trypanosoma cruzi. II. Antibody-dependent killing of bloodstream forms by mouse eosinophils and neutrophils.

Mouse mononuclear cells, neutrophils, and eosinophils were tested for their capacity to mediate antibody-dependent cytotoxicity against bloodstream trypomastigotes of Trypanosoma cruzi. Granulocyte populations were found to be far more effective than nonadherent mononuclear cells in an in vitro assay in which the number of motile parasites was measured. Eosinophils and neutrophils were observed to be equally efficient on a cell-per-cell basis in killing the trypomastigotes. These results were verified in parallel experiments in which trypomastigotes, after incubation with antibody and effector cells, were reinjected into susceptible mice and the survival of the animals was determined.