In vitro studies on the inhibitory effect of lymph-node cells. I. Antitumor activity of regional lymph-node cells from methylcholanthrene-induced sarcoma bearing mice on the same primary culture sarcoma cells

As a step in the elucidation of immunity of human cancer from the standpoint of homotransplantation immunity, we conducted mixed cultures of regional lymph node cells from C3H mouse isotransplanted with methylcholanthrene-induced sarcoma (MC-tumor) together with the primary culture MC-tumor cells, and observed the behaviors of these lymph node cells to the MC-tumor cells and compared the effects of these lymph node cells with lhose of normal mouse lymph node cells by counting the growth number of tumor cells and also by cinematography. As a result, it has been demonstrated that the regional lymph node cells from the mouse isotransplanted with the MC-tumor (2mm3 in size) acquire a strong antitumor activity by 14 days after the transplantation, but such antitumor activity diminishes and disappears in the terminal stage of cancer. When the number of these lymphocytes is increased, there can be observed some dosage effect, but no complete inhibition of the tumor growth can be attained. The cinematographic observations of these regional lymph node cells in the mixed culture with tumor cells reveal that lymphocytes of small to intermediate size aggregate onto the tumor cells and inhibit the movement of the latter.