Identification of feline monocytes and neutrophils as effector cells in antibody-dependent cellular cytotoxicity: sequential analysis, using light microscopy, histochemistry, and scanning electron microscopy.

Feline monocytes and neutrophils functioned as effector cells in antibody-dependent cellular cytotoxicity (ADCC) against antibody-coated chicken erythrocytes. Using light microscopy, effector cell populations were identified in effector-target cell interactions, with further characterization of these identical individual effector cells by histochemical evaluations and scanning electron microscopy. Monocytes and neutrophils, but not lymphocytes, were observed attacking target cells. Carbonyl iron depletion of monocytes and neutrophils from peripheral blood leukocytes caused a marked reduction from a mean of 62% to 3.6% lysis in ADCC as measured by a 4-hour 51Cr release assay. Effector cells functioning in the ADCC reaction were visualized, using sequential analysis and light microscopy, histochemistry, and scanning electron microscopy.