Final answer:
Eosinophils are the most effective immune cells in killing parasites through antibody-dependent cell cytotoxicity (ADCC) due to their ability to release cytotoxic granules upon binding to the Fc region of antibodies attached to parasites.
Step-by-step explanation:
The immune cells most effective in killing parasites through antibody-dependent cell cytotoxicity (ADCC) are eosinophils. Although other cells like natural killer cells, macrophages, and neutrophils can also mediate ADCC, eosinophils are particularly effective against larger pathogens, such as parasitic worms.
These cells are attracted by T cell cytokines and can bind to parasites via their Fc receptors when IgE labels the parasite. Upon binding, eosinophils release granule contents to kill the pathogen. In contrast, neutrophils and monocytes are primarily involved in phagocytosis, an immune mechanism different from ADCC.