Fig. 7

Expression of CD264 and cell cycle inhibitors in MSCs during serial passage. MSCs from a 36-year-old female donor were labeled on the cell surface with anti-CD264-phycoerythrin (PE), fixed, and permeabilized. Cell cycle inhibitors were detected by labeling fixed and permeabilized MSCs with anti-p53-Alexa Fluor (AF)488, anti-p21-AF488, and anti-p16-fluorescein isothiocyanate (FITC). a Representative histograms from flow cytometric analysis of single-labeled MSCs with monoclonal antibodies (mAbs) against CD264 and cell cycle inhibitors (grey) or isotype (white) at select passages (P; n = 10,000 cells/group). b Percentage of MSCs positive for CD264, p53, p21, and p16 as a function of passage number (n = 3 biological replicates). Cumulative cell doublings during serial passage: 15–17 (P3), 24–27 (P7), 31–33 (P11), and 35–38 (P14). Data are reported as mean ± SEM. *p < 0.05 versus P3 MSCs