Characterization of bovine leukocytes involved in antibody-dependent cell cytotoxicity

By the use of cell surface markers combined with physical separation techniques, bovine mononuclear leukocytes active as K cells in antibody-dependent cell cytotoxicity were characterized. The most active cells were glass wool adherent and were presumed to be macrophages. In the glass wool nonadherent population, heterogeneity was detected with respect to the complement (C) receptor but all cells expressed the Fc receptor. The C receptor-positive population adhered to nylon wool but was not a B cell and was assumed to be monocyte. The C receptor-negative population, the true lymphoid K cell, was nonadherent to nylon and was suggested to be an Fc receptor-positive null lymphocyte. The results were compared to those obtained with other species.