INTERLEUKIN-7 INDUCES DIFFERENTIAL LYMPHOKINE-ACTIVATED KILLER CELL ACTIVITY AGAINST HUMAN MELANOMA CELLS, KERATINOCYTES, AND ENDOTHELIAL CELLS

Abstract To assess the potential role of interleukin (IL)-7 in immunotherapy of human malignant melanoma, we have examined the lymphokine-activated killer (LAK) cell sensitivity of four human melanoma cell lines against LAK cells generated by IL-7 or IL-2. Lysis was determined by a 24-h cytotoxicity test using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). All melanoma cell lines were susceptible to IL-7- and IL-2- generated LAK cells. The sensitivity of melanoma cells to IL-2-induced LAK cells was higher compared to IL-7-induced LAK cells. At an effector target ratio of 20:1, the lysis by IL-7-induced LAK cells ranged between 41% and 52%, whereas IL-2-induced lysis ranged between 80% and 94% (p