miRNA-mediated control of exogenous during mesenchymal-epithelial transition increases measles vector reprogramming efficiency.

is a key mediator of induced pluripotent stem cell (iPSC) reprogramming, but the mechanistic insights into the role of exogenous and timelines that initiate pluripotency remain to be resolved. Here, using measles reprogramming vectors, we present microRNA (miRNA) targeting of exogenous to shut down its expression during the mesenchymal to the epithelial transition phase of reprogramming. We showed that exogenous is required only for the initiation of reprogramming and is dispensable for the maturation stage. However, the continuous expression of , , and is necessary for the maturation stage of the iPSC. Additionally, we demonstrate a novel application of miRNA targeting in a viral vector to contextually control the vector/transgene, ultimately leading to an improved reprogramming efficiency. This novel approach could be applied to other systems for improving the efficiency of vector-induced processes.