Cold target inhibition.

<p>FSP-specificity of four different CTL clones (A3, A6, 5A8 and 5H10) was examined. Firstly, an excess of unlabeled T2 cells either pulsed with FSP31 or with irrelevant peptide (P68) were added into experimental wells. Experiments were performed using (A) T2 and (B) HCT116 as target cells. Lysis of unpulsed HCT116 or exogenously FSP31-loaded T2 cells without cold targets served as control. Killing of target cells is depicted at different effector to target cell (E∶T) ratios. Secondly, recognition of HCT116 CRC target cells of two clones was blocked by addition of antibodies against CD3, HLA-A2 and pan-MHC-I at an E∶T ratio of 10∶1. All results are displayed as the mean and standard deviation from analysis performed in triplicate.