Transcriptional changes in macrophages after engulfing human cord tissue mensenchymal stromal cells

Purpose: The ability of MSCs to modulate macrophages is well documented but the mechanism is unknown. The goal of this study was to compare the transcriptome of macrophages that engulf MSCs to those that do not. Methods: Mouse splenocytes were cocultured with Qtracker labelled human cord tissue derived MSC for 3 days. Afterwards, CD11b+Ly6G- macrophages that were either Qtracker positive or negative were FACs sorted for RNA sequencing. Results: We determined that gene involved in antigen presentation and the activation of T cells were differentially expressed in macrophages that engulfed MSCs. Conclusion: Our study suggests that macrophages which engulf components of hCT-MSCs and are subsequently reprogrammed to suppress the activation of T cells, even after hCT-MSCs are no longer present. RNA profiles of macrophages that either engulf MSCs or do not were generated in paired biological triplicates using an Illumina HiSeq 4000.