The role of T cell sets in the rejection of a methylcholanthrene-induced sarcoma (S1509a) in syngeneic mice.

The ability of different T cell sets to confer protection in mice against a methylcholanthrene-induced sarcoma, S1509a, was examined. Intravenous infusion of lymph node and spleen cells from A/J donors immunized with S1509a into normal A/J recipients retarded subcutaneous growth of S1509a but did not lead to complete eradication of the tumor during a 9-day period of observation. This protective effect was lost if the transferred cells were treated with anti-Thy 1.2 and complement. The ability of different populations of lymphoid cells to retard tumor growth after inoculation with tumor cells subcutaneously was examined (Winn assay). Nylon-wool-passed cells from lymph nodes and spleens of tumor immunized animals were treated either with anti-Ly 1.2 or with anti-Ly 2.2 antiserums and complement and inoculated with tumor cells in normal A/J mice. The tumor was measured daily for 10 or more days. Ly l cells and unfractionated T cells efficiently suppressed tumor growth; Ly 23 cells had little or no effect. When small numbers of Ly 1 cells were injected along with twice as many Ly 23 cells, the growth of the tumor was also inhibited. Histologic examination of inoculated sites at 24-72 hours after local transfer showed a more intense mononuclear infiltrate in animals inoculated with tumor cells and T cells from immunized animals than in animals given injection with tumor cells alone, or with tumor cells and T cells from nonimmunized animals. The findings indicate that Ly 1 cells are capable of retarding the growth of the sarcoma, presumably by eliciting a delayed hypersensitivity reaction. By contrast, Ly 23 cells, which can mediate cytotoxicity, had little or no effect on tumor growth.