FIGURE 3.

Culture format and aggregation method influences MSC immunomodulatory phenotype and temporal response to pro‐inflammatory environments. Gene expression profiles for MSCs cultured in 2D monolayer (2D) or in 3D aggregates (SA, HD, or FC aggregation methods), in the presence (+) or absence (−) of IFN‐γ. The assessed genes were associated with cell proliferation and extracellular matrix synthesis (gray), or pro‐angiogenic and immunomodulatory paracrine factors (blue). Gene expression heatmaps are displayed as (A) Expression relative to TBP, (B) Fold expression relative to resting (ie, without IFN‐γ), and (C) Fold expression relative to day 0 resting conditions. D, Time course of PGE2 production by IFN‐γ‐primed MSC aggregates formed via SA, HD, and FC approaches. PGE2 was measured from media conditioned for 24 hours following IFN‐γ priming. Asterisks indicate statistically significant difference between denoted aggregation methods (*P < .05, **P < .01; two‐way analysis of variance with Tukey's post hoc test). (inset) Comparison of PGE2 secretion by day 7 aggregates. E, Fold change in PGE2 production by IFN‐γ‐primed MSC aggregates over 7 days, relative to day 0. FC, forced centrifugation; HD, hanging drop; IFN‐γ, interferon‐gamma; MSC, mesenchymal stromal cell; PGE2, prostaglandin E2; SA, self‐assembled