Characterization of B16 melanoma-specific cytotoxic T lymphocytes

A B16 melanoma-specific CD8⁺ T cell line (AB1) was established from the spleen cells of C57BL/6 mice cured of B16 melanoma with interleukin (IL)-12 treatment. The ABl line exclusively used T cell receptor V(β11). The AB1 cells exhibited a cytolytic activity against both syngeneic B16 melanoma and allogeneic P815 mastocytoma, whereas a cold inhibition assay revealed specificity of the AB1 cells against B16 melanoma. Their lostability to kill a class I loss variant of B16 melanoma was restored by the transfection of H- 2K(b) gene. In addition, their interferon (IFN)-γ production was significantly suppressed by the addition of anti-H-2K(b) monoclonal antibody, and RT-PCR analysis showed that the AB1 line expressed the mRNA encoding IFN- γ, but not IL-4 or IL-10. The experiment using synthetic peptides of tyrosinase-related protein-2 (TRP-2) revealed that the AB1 cells could recognize TRP-2_181-188 peptide. Moreover, the AB1 cells showed an in vivo antitumor effect against established pulmonary metastases of B16 melanoma. Overall, these results indicate that the Tcl-type V(β11) ⁺ AB1 cells exert an antitumor activity against syngeneic B16 melanoma through recognition of TRP-2_181-188 peptide in an H-2K(b)-restricted manner.