cytotoxicities

1. the degree to which an agent has specific destructive action on certain cells.

2. the possession of such destructive action, particularly in reference to lysis of cells by immune phenomena and to antineoplastic agents that selectively kill dividing cells. adj., adj cytotox´ic.

antibody-dependent cell-mediated cytotoxicity (ADCC) (antibody-dependent cellular cytotoxicity) lysis of target cells coated with antibody by effector cells with cytolytic activity and specific immunoglobulin receptors called Fc receptors, including K cells, macrophages, and granulocytes. Lysis of the target cell is extracellular, requires direct cell-to-cell contact, and does not involve complement.

cell-mediated cytotoxicity destruction of a target cell by specific lymphocytes, such as cytotoxic T lymphocytes or NK cells; it may be antibody-dependent (see antibody-dependent cell-mediated c.) or independent, as in certain cell-mediated hypersensitivity reactions.