Fig. 4: The supernatants of CD4⁺ T cell culture improved the functions of CIK cells in vitro.

A Illustration of co-culture of tumor cells (A549 and H520) and CIK cells. B Flow cytometric analysis of PD-1, CTLA-4, Tim-3, and LAG-3 expression in CD3⁺CD8⁺ T cells in a co-culture system (A549). C Flow cytometric examination of GzmB and IFN-γ production in CD3⁺CD8⁺ T cells in a co-culture system (A549). D The cytotoxicity of CIK or CD4⁻CIK cells against A549. E, F Flow cytometric assessment of Tim-3, IFN-γ, and GzmB expression in CD3⁺CD8⁺ T cells treated with tumor-conditioned medium in the presence (SCD4⁻CIK group) or absence (CD4⁻CIK group) of CD4⁺ T cells. G Flow cytometric or ELISA assessment of the concentration or MFI of 12 human inflammatory cytokines in tumor-conditioned medium in the presence or absence of CD4⁺ T cells. H–J Flow cytometric analysis of Tim-3, IFN-γ, and GzmB expression in CD3⁺CD8⁺ T or CD3⁺CD8⁺CD56⁺ T cells treated with either PBS, anti-IL-10 (200 ng/ml), or anti-IL-17 (100 ng/ml). K Western blot analysis of STAT3, AKT, and ERK phosphorylation in CD4⁻CIK cells treated with tumor-conditioned medium for 2 h. Error bars indicate SEM, *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 (one-way ANOVA or Student's t test).