[Spontaneous cell-mediated cytotoxicity of blood granulocytes and monocytes in vitro]

The in vitro studied bovine blood leucocytes display a spontaneous cell-mediated cytotoxicity (SCT) against 3H-thymidine labeled xenogeneic target cells L, estimated by the residual radioactivity. Using the effector-target cellular complex assay, it was found that cells of the heterogenous blood leucocyte population had different spontaneous target-binding activities. Granulocytes--eosinophils and neutrophils--were the most active effectors in the formation of effector-target cellular complexes during blood leucocyte SCT. The mononuclear SCT was represented by monocytes, while the spontaneous lymphocyte target-binding activity was very low. No basophil association with targets was detected.