ヒトNK様培養細胞KHYG‐1の細胞傷害における細胞傷害性顆粒の分泌動態

Three major therapies, “surgery”, “chemotherapy”, and “radiotherapy”, have been used to treat cancer. Recently, “immunotherapy” has attracted attention as the fourth treatment. We previously performed fundamental studies using NK cells, one cell type that has attracted attention in immunotherapy, and revealed that the surface CD56 antigen on the KHYG‐1 human NK cell-like cultured cells as a substitute for human NK cells can be used as an evaluation index of NK cell activity as in human NK cells. We also reported that the cytotoxicity of KHYG‐1 increases by IL‐2 stimulation. In this study, we improved the conventional cytotoxicity measurement method to evaluate the effects of a small amount of activator on NK cells. As a result, the cytotoxicity rate and measurement sensitivity at low-concentration IL‐2 stimulation were increased, and it became possible to evaluate the effects of a smaller amount of the activator. In the dynamic observation of KHYG‐1 intracellular granules, it was possible to observe in real time how the target cells were damaged after the influx of granules. Furthermore, the relationship between the activation of KHYG‐1 and the change in the intracellular expression level of granzyme B by IL‐2 stimulation was clarified, and future research tasks were shown.