Rejection of tumor cells in vitro: a T-cell-mediated reaction.

Cytoxic lymphoblasts (LBC) were produced by the co-cultivation of guinea-pig lymphoid cells from the thymus, lymph nodes, spleen, bone marrow and blood with syngeneic methylcholanthrene-induced sarcoma (MC-D) cells. The cytotoxic reaction was inhibited by pretreatment of the lymphoid cell populations with a rabbit antiserum specific for guinea-pig thymus-derived (T) lymphocytes. Supernatants of LBC inhibited the migration of peritoneal exudate cells, but did not contain lymphotoxin or a skin reactive factor. It is concluded that the cytotoxic cells are of T-cell origin.