Functional capacity of IDO5-specific T cells to kill cancer cell lines treated with IFN-γ for up-regulation of IDO, or treated with IDO ShRNA for down-regulation of IDO.
<p><i>(</i><i>a</i><i>),</i> Lysis by the IDO5-specific T-cell clone (RBS35) of the HLA-A2<sup>+</sup> breast cancer cell lines CAMA-1 <i>(right)</i> and MDA-MB-231 <i>(left)</i> before and after IFN-γ treatment. <i>(</i><i>b</i><i>)</i>, Histograms showing intracellular IDO expression in CAMA-1 before and after IFN-γ treatment. Data are representative of 3 experiments. Intracellular IDO expression was given by a one-tailed two sampled t-test comparing MFI<sub>IDO</sub> (dark histograms) and MFI<sub>Isotype control</sub> (light histograms), where MFI is the Mean Fluorescence Intensity. The fold of expression was defined as MFI<sub>IDO</sub>/MFI<sub>Isotype control</sub>. <i>Top:</i> CAMA-1 (<i>p</i> = 0.020 and MFI<sub>IDO</sub>/MFI<sub>Isotype control</sub> = 2.3). <i>Bottom:</i> CAMA-1 + IFN-γ treatment (<i>p</i> = 0.004 and MFI<sub>IDO</sub>/MFI<sub>Isotype control</sub> = 3.5). <i>(</i><i>c</i><i>),</i> Histograms showing HLA-A2 expression in CAMA-1 before and after IFN-γ treatment. Data are representative of 3 experiments. HLA-A2 expression was given by a one-tailed two sampled t-test comparing MFI<sub>HLA-A2</sub> (dark histograms) and MFI<sub>Isotype control</sub> (light histograms). The fold of expression was defined as MFI<sub>HLA-A2</sub>/MFI<sub>Isotype control</sub>. <i>Top:</i> CAMA-1 (<i>p</i> = 0.004 and MFI<sub>HLA-A2</sub>/MFI<sub>Isotype control</sub> = 43.7). <i>Bottom:</i> CAMA-1 + IFN-γ treatment (<i>p</i> = 0.002 and MFI<sub>IDO</sub>/MFI<sub>HLA-A2</sub> = 141.2). <i>(</i><i>d</i><i>)</i>, Lysis of the colon cancer cell line SW480 transfected with IDO ShRNA for down-regulation of IDO protein expression by an IDO5-specific T-cell bulk culture. As a positive control, SW480 cells transfected with control ShRNA were used as target cells. All assays were performed in different E∶T ratios. <i>(</i><i>e</i><i>)</i>, Histograms showing intracellular IDO expression in SW480 transfected with control ShRNA (<i>p</i> = 0.001 and MFI<sub>IDO</sub>/MFI<sub>Isotype control</sub> = 4.8) <i>(top)</i> and IDO ShRNA (<i>p</i> = 0.040 and MFI<sub>IDO</sub>/MFI<sub>Isotype control</sub> = 2.1) <i>(bottom)</i>.</p
