Discussion to d-8. Antitumor Effect of Heterologous Immune Lymphocytes in Experimental Gliomas and Fibrosarcomas Preliminary Report

There have been many reports which suggest the presence of tumor specific antigens. Their precise localization and chemical nature are, however, unfortunately obscure. As the tumor cells are arisen from the corresponding normal cells by unknown process of malignnant transformation, their antigenicity is usually extremely weak. The immune reactions to weak antigens, such as antigens of transplantation type including tumor antigens, are reported to be mainly mediated by so-called cell bound antibodies, that is, sensitized lymphoid cells. Alexander et al. have treated primary fibrosarcomas in rats with immune lymphocytes derived from syngeneic, allogeneic or heterologous sources. We attempted to show the antitumor effect of heterologous immune lymphocytes, because of some possibilities that this type of method may eventually become clinically useful for eliminating malignant cells left behind after removal of major part of the tumor. We do not believe, however, that this type of procedure is likely to be of value when the bulk of the tumor remains in situ or tumor metastases are extensive. Animals, available in the experiments, were randomly bred C57BL mice in closed colony and rats of Wister strain. Transplantable gliomas and fibrosarcomas were induced in mice by the intracerebral and subcutaneous implantations of MC powder. Rats were sensitized with a piece of mouse tumor in the route of subcutaneous implantation. Thoracic duct lymphocytes of these rats were obtained by cannulation 7 and 14 days later. Lymph was collected over a period of 24 hrs. into a refrigerated flask containing heparin and tissue culture medium. The number of lymphocytes usually amounted to 107-1011/24 hrs. per rat, and 15 to 25% of the collected lymphocytes were lymphoblasts. These sensitized lymphocytes, 10 to 1000 times as many as the tumor cells, were injected intravenously in mice and at the same time the tumor cells were trans-