Fig. 2: Enhancement of NK cell-mediated apoptosis of BC cell lines following treatment with IFN-γ + TNF-α.

A MCF-7, MDA-MB-231 and MDA-MB-468 BC cell lines were untreated or treated for 24 h with low, non-toxic doses of IFN-γ + TNF-α and then used as target cells for NK cell-apoptotic assay. Untreated or IFN-γ + TNF-α-treated BC cell lines without NK cells were used as negative controls, while untreated or IFN-γ + TNF-α-treated BC cell lines co-cultured with Z-VAD-FMK pre-treated NK cells were used as apoptosis controls. A representative experiment of the four performed (B) is shown for each indicated BC cell line. The percentage of cells in early apoptosis (Annexin V⁺ 7-AAD^-), late apoptosis (Annexin V⁺ 7-AAD⁺) and dead state (Annexin V^- 7-AAD⁺) are shown for each plot. B A summary of four independent experiments is shown. C MDA-MB-231 BC cell lines were untreated or treated for 24 h with low, non-toxic doses of IFN-γ + TNF-α and then used as target cells for neutralizing NK cell-apoptotic assay by pre-incubating NK cells with neutralizing antibodies such as α-FAS-L, α-TRAIL, α-LFA-1 or a cocktail of all three antibodies, before co-culturing them with BC cells. A representative experiment of the four performed with MDA-MB-231 cell line (D) is shown. The percentage of cells in early apoptosis, late apoptosis and dead state are shown for each plot. D A summary of four independent experiments is shown. Mean ± SD; *p < 0.05, **p < 0.01; p value, two tailed unpaired Student-t test.