Induction of lymphokine-activated killer (LAK) cells from tumor-bearer's splenocytes and their application to adoptive immunotherapy

We attempted to generate the LAK cells from tumor-bearer's spleens and to use them as effectors for adoptive immunotherapy. We investigated whether tumor-bearer's splenocytes cultured with interleukin-2 (IL-2) in vitro could lyse various tumor targets and whether these effectors were applicable to immunotherapeutic potentials. In vitro cytotoxicity tests revealed that these LAK cells generated from tumor-bearer's splenocytes exhibited potent cytotoxicity. These LAK cells exhibited antitumor effects in a tumor neutralization assay (Winn assay) in vivo. Furthermore, LAK cells infused intravenously into syngeneic mice with systemic metastasis significantly lengthened survival time compared with the control mice given cultured cells without interleukin-2 (IL-2). These results suggest that the use of LAK cells from tumor-bearer's splenocytes may provide a valuable method for the adoptive therapy of human neoplasms as well.