Successful systemic adoptive immunotherapy of a disseminated solid syngeneic murine tumor with long-term cultured T cells

Few examples exist of the effective treatment of established syngeneic solid tumors using specific adoptive immunotherapy. A major limitation to the application of adoptive immunotherapy has been the lack of techniques to provide sufficiently large numbers of lymphoid cells with appropriate specific antitumor activity. Recently, we have explored the possible use of lymphoid cells expanded in Interleukin-2 (IL-2) for the adoptive immunotherapy of syngeneic murine tumors. IL-2, free of lectin, (LF-IL-2) is capable of selectively growing activated lymphoid cells as well as augmenting the generation of cytotoxic cells in vitro. Using these techniques, we have previously reported that cells specifically sensitized and then expanded in LF-IL-2 were capable of accelerating allogeneic skin graft rejection when adoptively transferred to normal hosts. Recently, we established long-term T-lymphoid lines specifically lytic for the syngeneic FBL-3 lymphoma and used these cells with cyclophosphamide to successfully treat animals with disseminated micrometastatic tumor. In this report, we have extended our observations to the treatment of an established solid syngeneic footpad tumor at a time when this tumor is also disseminated throughout the host.