Fig. 6.

Magnitude of α_V and α₅ integrin subunits identifies MSC subpopulations of varying immunosuppressive capacity with IFN-γ licensing on fibrin hydrogels. (A) FACS plots of α_V expression (Left) and α₅ expression (Right) of various MSC cell lines. (B) Representative FACS plot of FACS-sorted α_V^LOα₅^LO-expressing MSCs, α_V^MEDα₅^MED-expressing MSCs, and α_V^HIα₅^HI-expressing MSCs and 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 fibrin. (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 fibrin. Labels for groups in C–F are shown in F, where “LO” denotes α_V^LOα₅^LO-expressing MSCs, “MED” denotes α_V^MEDα₅^MED-expressing MSCs, “HI” denotes α_V^HIα₅^HI-expressing MSCs, “stain” denotes unsorted MSCs stained with FACS-sorting antibodies, and “unstain” denotes unsorted, unstained MSCs. n = 4 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.