Figure 7. Curcumin modifies the cytolytic machinery in CD8⁺ T lymphocytes, NK and NKL cells. (A) Frequency of CD107a⁺ degranulation by T CD8⁺ and NK cells after stimulation with anti-NKG2D mAb. Untreated or curcumin-treated (4 µM) CD8⁺ and NK cells were cultured for 6 h in the presence of activating anti-NKG2D mAb or isotype control, and expression of membrane CD107a was measured by flow cytometry. Data represent the mean ± SD values from triplicate experiments. (B) Granzyme B and perforin expression was analyzed in the NKL cell line before and after treatment with 4 µM of curcumin for 24 h by qRT-PCR and flow cytometry. GAPDH was used as a control and results are represented as the mean ± SD of three independent experiments. Histograms are representative of an experiment for intracellular staining of granzyme B and perforin. (C) Frequency of IFN-γ production by untreated or 4 µM curcumin-treated NKL cells after coculture for 6 h with C1R or C1R-MICA cells at E: T ratio 1:1. Data represent mean ± SD values from triplicate experiments.*p < 0.05.