Lysis of fresh and cultured autologous tumor by human lymphocytes cultured in T-cell growth factor

Human lymphocytes derived from the peripheral blood of patients with a variety of cancers were grown in T-cell growth factor (TCGF) and tested in a 4-hr ⁵¹ Cr microcytotoxicity assay against fresh and cultured autologous tumor, autologous cultured skin fibroblasts, and autologous fresh peripheral blood lymphocytes. Lymphocytes grown in TCGF caused significant lysis of autologous cultured tumor and fibroblasts but caused little lysis of fresh autologous peripheral blood lymphocytes in all of seven patients tested. This lytic activity against autologous cultured cells was not dependent on the source of serum used in culturing the lymphoid cells or the targets. Lymphoid cells grown in TCGF also were capable of causing selective lysis of fresh autologous tumor cells that had never been in culture in five of nine patients. Lymphoid cells growing In lectin-free TCGF caused selective lysis of autologous tumor in five of seven patients. These observations demonstrate that peripheral lymphoid cells grown in TCGF can be lytic for autologous cultured and autologous fresh tumor compared to the lysis of fresh autologous peripheral blood lymphocytes. The fact that these auto-reactive cells, lytic for tumor, may be expanded to large numbers in TCGF suggests a possible role for these cells in studies of the control of the cytotoxic response of activated cells to tumor and possibly in the immunotherapy of tumors as well.