[Antigenic reactivation in vitro of the cytotoxic activity of lymphoid cells from mice bearing syngeneic tumors].

The cytotoxic activity of lymphoid cells from mice bearing syngeneic sarcomas is increased when these cells are preincubated on heavily irradiated cells of the same tumours. This secondary stimulation is highest at the time when the cytotoxicity measured directly is relatively low. In consequence, whatever the age of the tumour, the level of cytotoxicity reached (35-45 %) cannot be increased further in normal conditions.