Figure 4

Blocking of the NKG2D receptor on effector NKL cells. NKL cells were co-cultured with the different cell lines for 4 h. The NKL cells were subsequently removed from co-culturing cells (SiHa, HeLa, C33A or HaCaT) and the NKL cells were additionally incubated with an anti-NKG2D monoclonal antibody at blocking concentration (30 μg/mL) or with IgG1 isotype control (clone MOPC-21; Biolegend, San Diego, CA, USA). Afterwards, NKL cells were incubated for 3 h using GFP-transfected K562 as target cells at an E:T ratio of 10:1. Dead target cells were discriminated based on GFP + and PI + population. The addition of blocking anti-NKG2D monoclonal antibody to the NKL cells had an additive effect on the previoulsy observed cytotoxicity diminution due to co-culture; this effect was dramatically more evident on NKL cells previously exposed to SiHa cells. Experiments were performed in duplicate and repeated four times. Data are expressed as mean ± SEM. * p < 0.05.