Figure 4.

The tumor-specific cytotoxicity of CD8⁺ T cells is enhanced in the presence of IL-9 in vitro. (A, B) The effect of IL-9 on tumor-specific cytotoxicity was evaluated by means of cytotoxic assay in the presence or absence of rIL-9, using MO4 cells as target cells and lymph node cells from tumor-bearing OT-I mice or C57B6/N mice (WT) as effector cells. (A) The MFI levels of granzyme B and peroforin in CD8⁺ T cells after the assay analyzed by flow cytometry. (B) The bar graph shows the % of target cell death. (C) The effect of IL-9 on the cytotoxic ability of tumor-specific CD8⁺ T cells. (D) Immunohistochemistry analysis of IL-9 (left) and CD8⁺ (right) in the human melanoma tissues. The figure shows the representative data (patient #8).