Tankyrase inhibition facilitates RNA-mediated reprogramming of human somatic cells to naïve pluripotency

In contrast to conventional human pluripotent stem cells (hPSC) that are related to post-implantation embryo stages, naïve hPSC exhibit features of pre-implantation epiblast. Naïve hPSC are established by resetting conventional hPSC, or are derived from dissociated embryo inner cell masses. Here we investigate conditions for transgene-free reprogramming of human somatic cells to naïve pluripotency. We find that RNA-mediated induction of naïve pluripotency is enhanced by Wnt inhibition. We demonstrate application to independent human fibroblast cultures and endothelial progenitor cells and show that induced naïve hPSC can be clonally expanded with a diploid karyotype. They exhibit distinctive surface marker, transcriptome, and methylome properties of naïve epiblast identity. Induced naïve hPSC lines undergo somatic lineage differentiation following formative transition. Efficient, facile, and reliable induction of transgene free naïve hPSC offers a robust platform for delineation of human reprogramming trajectories and for evaluating the attributes of isogenic naïve versus conventional hPSC. Overall design: WGBS-seq of newly generated human iPSCs lines