EFFECTS OF INSULIN AND TRANSFERRIN ON THE GENERATION OF LYMPHOKINE-ACTIVATED KILLER-CELLS IN SERUM-FREE MEDIUM

We have developed a serum-free medium designated RDSF for the generati on of LAK cells based on RD6F medium, which was originally developed a s a serum-free medium for the growth of myeloma and hybridoma cells. T he cytotoxic activity of LAK cells generated in RDSF against Raji, K56 2 and oral cancer cells, is 3-4 times that of LAK cells generated in m edium containing 10% human type AB serum. RDSF medium consisted of nut rient mixture supplemented with transferrin, 2-aminoethanol, 2-mercapt oethanol, sodium selenite and interleukin-2. In this study, we have fo und that insulin, which has been shown to be the most important polype ptide hormone in serum-free media for animal cells, inhibited the gene ration of cytotoxic activity of LAK cells cultured from peripheral blo od lymphocytes. In addition, we found that transferrin was an essentia l component for the growth and generation of LAK cells in serum-free c ulture. These results suggest that RDSF may be useful in adoptive immu notherapy for cancer as well as for studying factors involved in the g rowth and differentiation of LAK cells.