[Adoptive immunotherapy in experimental brain tumor in rats--induction of LAK cells and their biological characteristic].

We have investigated the biological characteristic of Lymphokine Activated Killer (LAK) cells induced from spleen cells (SPC) of Fischer rats. Supernatant of 48 hour culture medium (RPMI-1640, 10% FBS, 2-ME: 5 X 10(-5) M, HEPES: 10 mM) of SPC (1 X 10(6)/ml) from Wistar rats in the presence of Con A (5 micrograms/ml) was used as Interleukin 2 (IL-2). LAK cells were generated by co-cultivation of SPC (4 X 10(6)/ml) from Fischer rats with peak reactivity on the 2 nd or 3 rd day of culture. Lytic activity was observed against not only syngeneic tumor cells (T9, RSV induced brain tumor), but also allogenic (KMT-17) and xenogenic (K 562, Raji cell, G 361, YAC-1) tumor cells, while no lytic activity was observed against normal brain cells. Cell depletion test, dye exclution test and immunofluorescence method using monoclonal Antibodies (mAbs) revealed that LAK cells partially belonged to the population of activated T cell group (W 3/13, OX 4 positive) but the precursor cells did not react with any mAbs used (W 3/13, W 3/25, OX 4, OX 8). On the basis of these results, more effective and useful administration of LAK cells is now under investigations by using the rats with brain tumors.