Fig. 4.

Measurement of the cytotoxic activity of PBMC against TF-overexpressing and control HT29 cells, pre-incubated with plasma. pEGFP-TF transfected and un-transfected HT29 cells (5×10⁴ per well) were labelled with SNARF-1 in culture medium (200 μl final volume). Ten random views within each well were recorded using a fluorescence microscope. Human normal plasma was added to the wells at final concentrations of 0, 10 and 20% (v/v) and incubated for 15 min prior to a 4 h incubation at 37°C, with two preparations of PBMC at a 10:1 ratio (PBMC:HT29). Subsequently, ten random sectors were analysed as before. Analysis was carried out using the Image Pro plus program and the data were calculated as the percentage reduction in cell number after incubation with PBMC cells against the initial number of viable HT29 cells. The data represent the mean of duplicates±standard deviation