KILLER CELLS

killer cells: translation

(= K cells)

(1) Mammalian cells which can lyse antibody-coated target cells. They have a receptor for the Fc portion of IgG, and are probably of the mononuclear phagocyte lineage, though some may be lymphocytes. Not to be confused with cytotoxic T-cells (CTL) which recognize targets by other means and are clearly a subset of T-lymphocytes: this confusion exists in the early literature.

(2) (NK cells) Natural killer cells are CD3-negative large granular lymphocytes, mediating cytolytic reactions that do not require expression of Class I or II major histocompatibility antigens on the target cell.

(3) (LAK cells) Lymphokine-activated killer cells are NK cells activated by interleukin-2.