Figure 3

NKL cell cytotoxic activity is impaired after exposing NKL cells with cervical cancer cells. NKL cells were co-cultured with the different cell lines for 4 h. Subsequently, the NKL cells were removed from each co-culturing cells (SiHa, HeLa, C33A or HaCaT) and the cytotoxicity was evaluated. The NKL cells were incubated for 3 h using GFP-transfected K562 as target cells at different E:T ratios (1:1, 5:1, and 10:1) for 3 h. Dead target cells were discriminated based on GFP + and PI + population. The co-culture of NKL with HaCaT cells does not produce any significant change in NKL cytotoxic activity (A). After co-culture with C33A, we see an increase in the cytotoxic activity of NKL cells (B). In contrast, co-cultures with SiHa (C) and HeLa cells (D) considerably decrease the cytotoxic activity of NKL cells. Experiments were performed in triplicate and repeated three times, for a total of nine data points per sample. Data are expressed as mean ± SEM. * p < 0.05, CM: complete medium.