Fig. 6: Neutralizing IL-16 reverses tumor growth and CD8⁺ T cell cytotoxicity in Aurora-A knockdown CT26 tumors.

A A schematic illustration of antibody treatment (IgG or anti-IL16) in the allogenic animal model is shown. Lenti-shGFP-infected and lanti-shmaurka-1-infected CT26 were subcutaneously injected into Balb/c mice; IgG or anti-IL-16 antibodies were intratumorally (IT) injected on day 8, day 11, and day 14 of post-subcutaneous injection. Tumor volume was measured every three days. Two-way ANOVA is used for statistical analysis. Data are shown as mean ± SEM; n = 3 or 4. *p-value < 0.05. B−K Mice from Fig. 6A were sacrificed on day 23 post-subcutaneous injection, and tumor weights were measured (B). Tumor-infiltrating leukocytes (C), T cells (D), CD8⁺ T cells (E), CD4⁺ T cells (F), Th1 cells (IFNγ⁺ CD4⁺ T cells) (G), IFNγ⁺ CD8⁺ T cells (H), TNFa⁺ CD8⁺ T cell (I), PD1⁺ CD8⁺ T cells (J), and CD25⁺ CD4⁺ T cells (K) were measured by flow cytometry. Student’s t-test is used for statistical analysis. Data are shown as mean ± SEM; n = 3 or 4. L, M CD8⁺ T cells were purified from Balb/c mice splenocytes. The purified CD8⁺ T cells were cultured in conditioned media collected from lenti-shGFP-infected and lenti-shmaurka (#1 and #2)-infected CT26 plus anti-CD3/CD28 antibodies without (L) or with recombinant IL-16 (M) for 48 h. The cytotoxicity of CD8⁺ T cells in splenocytes was measured by flow cytometry using anti-CD107 antibodies. The relative fold change of CD107⁺/CD8⁺ T cells are shown. Student’s t-test is used for statistical analysis. Data are shown as mean ± SEM. *p-value < 0.05; **p-value < 0.01; ***p-value < 0.001; ****p-value < 0.0001.