[Subcutaneous injection of spleen cells from mice bearing large methylcholanthrene-induced sarcoma enhances subcutaneous tumors and artificial pulmonary metastases].

To examine the effect of spleen cell on host antitumor immunity, spleen cells from mice bearing large Methylcholanthrene-induced sarcoma (MCA-F) (F4w spc) were injected subcutaneously into mice which had been inoculated subcutaneously with MCA-F cells or intravenously with the subline from MCA-F cells which had high potential of metastasis (FLn2). F4w spc enhanced significantly the growth of subcutaneous MCA-F tumor in a dose-dependent fashion (p less than 0.05) and increased the number of metastatic lesions induced by intravenous FLn2, but not spleen cells from normal mice or spleen cells from mice bearing MCA-D tumor which is antigenically different from MCA-F. These results suggest that spleen cells of mice bearing a large tumor have a component suppressing specifically antitumor immunity. In this study, effects of spleen cells were assessed by the subcutaneous injection into tumor bearing mice instead of Winn's assay, and this method was thought to be useful for analysis of effector cells in tumor immunity.