Figure 6.

The activation of NK cells within PBMC is Type I interferon-dependent. PBMC from healthy donor blood were treated with 0 or 1 pfu per cell reovirus for 12 hr in the presence or absence of either anti-IFN-α/β neutralising antibodies (IFN block) or isotype control (IFN isotype). (a) Cell-surface expression of CD69 within the CD3-CD56+ NK cell population was determined by flow cytometry. Mean values + SEM from three independent experiments are shown alongside a representative flow cytometry overlay histogram. (b) PBMC were cocultured with SW480 and SW620s, and cell-surface expression of CD107 within the CD3-CD56+ NK cell population was assessed by flow cytometry. Mean values + SEM of three independent experiments are shown. (c) PBMC were cocultured at different E:T ratios with ⁵¹Cr-labelled SW480 and SW620s. ⁵¹Cr release was quantified and percentage of target cell lysis determined. Graphs are representative of three independent experiments. All experiments were performed in the presence of 7.5% HS. Statistical significance is denoted by *p < 0.05.