Inhibition of Tumor Growth Mediated by Lymphocytes Sensitized in Vitro to a Syngeneic Murine Teratocarcinoma 402AX

Abstract

TerC, a cell line derived from a strain 129 teratocarcinoma 402AX, was used to sensitize syngeneic 129 (H-2^bc) splenic lymphocytes in vitro. The effector cells generated inhibited in vitro growth of TerC as measured by an ¹²⁵I-IUDR post-labeling technique. It was also shown, with a modified Winn assay, that the sensitized cells were effective in preventing TerC growth in vivo. The effector lymphocyte was nonadherent to nylon wool, was sensitive to anti-Thy-1·2 + C, and was phenotypically Ly 1^-2⁺. The anti-TerC effector T lymphocytes were not functional in a ⁵¹Cr-release assay. However, this failure to lyse appears not to be due to some intrinsic membrane resistance since both BCG and ConA-activated killers were able to lyse TerC. The TerC-sensitized lymphocytes displayed no H-2 restriction and were able to growth inhibit in vitro a wide range of tumorigenic cell lines, e.g., P815 (H-2^d), EL-4 (H-2^b),Sal (H-2^a), and BALB/c (H-2^d) 3T12. Mouse blastocyst cell lines were also inhibited. BALB/c 3T3 and mouse fibroblast cell strains were not growth inhibited. Thus, it appears that oncofetal antigens expressed on TerC are capable of initiating a cell-mediated response and that these antigenic specificities are shared by many transformed cell lines.