Fig. 7.

Magnitude of α₂ and β₁ integrin subunits identifies MSC subpopulations of varying immunosuppressive capacity with IFN-γ licensing on collagen hydrogels. (A) FACS plots of α₂ expression (Left) and β₁ expression (Right) of various MSC cell lines. (B) Representative FACS-sorting plot of FACs-sorted α₂^LOβ₁^LO-expressing MSCs, α₂^MEDβ₁^MED-expressing MSCs, and α₂^HIβ₁^HI-expressing MSCs with unsorted MSCs. (C) The percent proliferating and (D) CD25⁺ CD4⁺ T cells in the presence of FACS-sorted or unsorted MSCs lines with IFN-γ licensing, cultured on collagen. (E) Activity of IDO and (F) mean fluorescence intensity (MFI) of PD-L1 of FACS-sorted or unsorted MSCs lines with IFN-γ licensing, cultured on collagen. Labels for groups in C–F are shown in F, where “LO” denotes α₂^LOβ₁^LO-expressing MSCs, “MED” denotes α₂^MEDβ₁^MED-expressing MSCs, “HI” denotes α₂^HIβ₁^HI-expressing MSCs, “stain” denotes unsorted MSCs stained with FACS-sorting antibodies, and “unstain” denotes unsorted, unstained MSCs. n = 3 to 6 for all data sets. Data are presented as means ± SD. Significance is denoted by *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, or ****P ≤ 0.0001 by one-way ANOVA with Tukey’s post hoc test; separate comparisons were made between conditions of each cell line.