Intracellular STAT1-CC upregulates HLA class I surface expression in IFN-γ resistant (GR17-1) cells.

<p>GR17-1 cells were transfected with STAT1, STAT1-CC or STAT1-CC-Y701F plasmid using FuGENE 6 reagent for 72 hours with or without IFN-γ treatment. After 72 hours, the cells were harvested and stained with a phycoerythrin-conjugated anti-human HLA antibody. Surface HLA-1 expression was then quantified by flow cytometry. (<b>A</b>) Each histogram is representative of six independent experiments. The red cell population in each histogram represents IFN-γ naïve cells and the blue cell population represents IFN-γ treated cells. (<b>B</b>) Mean fluorescence intensity of six independent experiments per group. Values represent fold increase in HLA1 expression after the addition of IFN-γ. Mock represents GR17-1 cells without plasmid transfection. Asterisk (*) denotes a significant (p<0.05) increase in HLA1 in STAT1-CC transfected cells plus IFN-γ compared to mock.