Natural Killer Cells and Cytotoxic T Cells Induce DNA Fragmentation in Both Human and Murine Target Cells in Vitro

Abstract
DNA fragmentation induced by cytolytic lymphocytes in human erythromyeloid cell line K562 and murine T lymphoma cell line YAC‐1 was investigated by means of agarose gel electrophoresis. Murine natural killer (NK) and cytotoxic T (Tc) cells induced DNA fragmentation in YAC‐1 cells, with the fragments being approximately multiples of 180 bp. More significantly, murine NK cells can induce a similar pattern of DNA fragmentation in human K562 cells. Therefore, cytolytic lymphocytes can induce apoptosis or programmed cell death in human target cells.