Fig. 1

Expression of cell-surface receptors upon stimulation with IFNγ. a Histograms showing antibody staining of cell surface-expressed IFNγ-R1 (colored white) on hfcMSCs from one representative donor compared to IgG1 PE-negative controls (colored gray). IFNγ-R1 was constitutively expressed on all hfcMSCs, with no change in the frequency of positive cells with IFNγ exposure. b Scatter dot plot showing median fluorescence intensity (MFI) of IFNγ-R1 surface expression from cell cultures using four different donors. Bar indicates mean values ± standard error of the mean (SEM). The significantly increased expression remained after removal of IFNγ. c Density plots showing simultaneous staining of HLA I and HLA II molecules on the cell surface of hfcMSCs from one representative donor. Expression of HLA II was induced upon IFNγ stimulation and further increased after 7 days of stimulation. d MFI values ±SEM of HLA I expression are depicted in the scatter dot plot. e MFI values ±SEM of HLA II expression are depicted in the scatter dot plot. Both HLA types remained upregulated at 2 days after withdrawal of IFNγ. Independent experiments were carried out in triplicates, each time using an n = 4 donors. *P < 0.05, **P < 0.01, ***P < 0.001