Activation and expansion of tumor-derived activated cells for therapeutic use

We obtained tumor specimens from patients with cancer in an effort to activate and expand the tumor-infiltrating lymphocytes for therapeutic use. With the use of finely minced tumor preparations from eight different tumor types, recombinant interleukin-2, and lymphokine-activated killer cell-conditioned medium, lymphocytes were expanded in vitro. After 4 weeks, the tumor cells were virtually absent from the cultures. At this point, the lymphocytes were termed "tumor-derived activated cells" (TDACs). Over 90% of the TDACs from each of the different tumor types were T lymphocytes, and the percentage of cells expressing either CD4 or CD8 varied considerably from population to population. The lymphocytes showed specific cytolytic activity in melanoma and colon and renal cell carcinomas. Continued expansion and long-term growth of the TDACs, as well as maintenance of the cytolytic activity, were achieved by periodic stimulation of the TDACs with irradiated autologous tumor cells. In a clinical study of 28 patients with cancer, we generated a mean number of 1.2 X 10(11) TDACs in an average time in culture of 69 days. These TDACs were subsequently infused into the patients with cancer. TDACs appear to represent an important resource for biotherapy of patients with cancer.