Figure 1.

Vector and study design of Tet-inducible IFN-γ-expressing DFT1 cells (DFT1.Tet/IFN-γ). (A) Expression vector for tetracycline (tet)-controlled inducible IFN-γ expression in DFT1 cells. ITR, inverted terminal repeats; TCE, tet-responsive promoter; IRES, internal ribosomal entry site; tTA, tet-controlled transactivator. (B) Timeline for dox+/– treatments of DFT1.Tet/IFN-γ used in subsequent experiments. DFT1.Tet/IFN-γ cultured in 100 ng/ml doxycycline (Dox) was split into four groups with doxycycline removed or doxycycline continually replenished for 1, 2, 5, or 10 days. Cells were analyzed for: (i) surface β₂-m and PD-L1 upregulation; (ii) ability to stimulate MHC-I upregulation on wild type DFT1 cells (DFT1.WT) using the supernatant or by co-culture; and (iii) cell proliferation and viability in response to doxycycline removal.