Effector cells in avian spontaneous and antibody-dependent cell-mediated cytotoxicity.

Using effector cells from chickens and quails, antibody-dependent and spontaneous cell-mediated cytotoxicity (ADCC and SCMC) were studied in a 51chromium-release microcytotoxicity assay against erythrocytes and several tumor cells as targets. The effector cells mediating both ADCC and SCMC against tumor targets, as well as those active in ADCC against erythrocytes, exhibited similar characteristics: they were adherent cells of high density, which could be removed by treatment with carbonyl iron and magnet. The effector cell concentration was highest in the peripheral blood and lower in the spleen, whereas no activity was found in thymus and bursa. Lysis was detectable after 15 min of incubation, and the reaction was completed after a few hours. A rabbit antiserum was found to be able to induce ADCC against sheep erythrocytes, but it did so less effectively than a chicken antiserum. Studies on the target specificity of SCMC revealed a preferential destruction of xenogeneic lymphoma targets. These findings are discussed with respect to differences between the avian effector cells and the mammalian K and NK cells.