XXXX -activated killer cells can kill target cells not only by early killing but also by late killing, and the late killing level against autotumor cell line.

@entity1 @entity2456 @entity5 @entity1199 @entity405
Generally, @entity1199 -activated killer (LAK) cells kill target cells early after the LAK cells adhere to them. In this study, we describe that LAK cells can also kill at a later time, such as 24-96 h. LAK cells were generated from a @entity5 @entity1 and healthy volunteers. As target cells, the @entity1 's autotumor cell line H41 was used. When LAK cells were added to the target cells in a culture well, the LAK cells killed the target cells by cell-cell adhesion within 1-4 h (early killing), but not all cells were killed. The LAK cells were then removed. However, the remaining cells ultimately died 24-96 h later (late killing). The late killing was different from the early killing because numerous granules and vacuoles appeared in the cytoplasm. The late killing was not induced by adding supernatant of the LAK cell culture, suggesting that LAK-target cell contact may be necessary for the killing. The cell injury was inhibited by @entity2456 (lysosome inhibitor). It suggests that the vacuoles may be caused by activated lysosome. The @entity1 's LAK cells induced late killing at high levels. There was a high percentage of @entity405 (+)CD16(+) cells in the peripheral blood lymphocytes (PBL). This subset induced late killing more effectively than the @entity405 (-)CD16(+) subset. Killing was more conspicuous against H41 than against allogeneic cell line T98G. This type of killing is noteworthy for understanding of killing mechanism of LAK cells.
