Table 3.
Baseline and IFN-G-induced expression of immune checkpoint proteins in solid tumor cells
| Entity | Cell line | PD-L1 | PD-L2 | PD-1 | CD28 | CD47 | CD80 | CD83 | CD86 | CD243 | CD366 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Colon cancer | HCT15 | +* | - | - | - | ++* | +/- | +/- | - | + | +/- |
| HCT116 | +* | - | - | - | ++* | +/- | +/- | +/- | - | - | |
| HT29 | +* | - | - | - | ++* | +/- | +/- | - | - | - | |
| Breast cancer | MCF7 | +* | - | - | - | ++ | +/- | +/- | - | - | +/- |
| SKBR3 | +* | - | - | - | ++* | - | - | - | - | - | |
| T47D | +* | - | - | +/- | ++* | + | + | - | - | +/- | |
| Melanoma | 607B | +* | - | - | - | +++ | +/- | + | +/- | +/- | +/- |
| A375 | +* | - | - | - | +++* | +/- | + | +/- | - | +/- | |
| MEL-JUSO | ++* | +/- | - | - | +++ | + | + | - | +/- | +/- | |
| Ovarian cancer | A2780 | +/-* | - | - | - | ++* | +/- | +/- | - | - | - |
| HEY | +* | - | - | +/- | ++* | - | +/- | +/- | - | - | |
| SKOV3 | +/-* | - | - | +/- | ++ | +/- | +/- | +/- | - | +/- | |
| Lung cancer | H1993 | +* | +/- | - | - | ++ | + | + | +/- | +/- | + |
| H2073 | +* | +/- | - | - | ++ | +/- | + | +/- | - | +/- | |
| Prostate cancer | DU-145 | +* | +/- | - | + | ++ | +/- | + | +/- | +/- | - |
| LNCAP | +* | - | - | +/- | ++ | +/- | + | +/- | - | - |
Summary of the tested checkpoint protein expression in the cancer cell lines. Scoring system: staining index (SI) was calculated (ratio of median fluorescence intensities obtained with specific antibody and isotype-matched control antibody) and scored according to the following system: -, SI < 1.30; +/-, SI 1.31-3.00; +, SI 3.01-10.00; ++, SI 10.01-100; +++, SI > 100. The asterisk (*) indicates that the expression of the checkpoint marker is increased after 100 U/ml IFN-G treatment for 24 hours. Abbreviations: IFN-G, interferon gamma; PD-L1, programmed cell death-ligand 1; PD-L2, programmed cell death-ligand 2; PD-1, programmed cell death-1; CD, cluster of differentiation.