Fig. 1

Direct conversion of adult human PBCs into iNSCs. a Schematic representation of PB-iNSC generation. b–e Within 1 week after infection of PBCs (b), actively proliferating neuroepithelial colonies (c) immunopositive for early NSC markers PAX6 and NES (d) emerge, which can be further expanded to form stably self-renewing iNSCs (e). f RT-PCR confirms the fast decline of SeV-SOX2 and SeV-c-MYC expression during 39 °C incubation and the persistent absence of SeV genomes in iNSC cultures. g–l Transgene-free iNSCs express typical neural lineage markers, including early neuroectoderm and neural rosette markers SOX2 (g), NES (g, h), DACH1 (h), PLZF (i), ZO-1 (i), and PAX6 (j). A small fraction of cells is immunopositive for the neural crest markers AP2α (j, 2.0 ± 0.7%, mean ± s.d., n = 3), HNK1 (k, 17.5 ± 8.3%, n = 3), and SOX10 (l, 2.4 ± 0.3%, n = 3). m Proliferating iNSCs show prominent expression of the proliferation marker Ki67. P5–P14: passage numbers; PB-SeV (SM): PBCs infected with SeV-SOX2 and SeV-c-MYC; PB-SeV (−): PBCs without infection. Scale bars: 200 μm (b–e); 50 μm (g–m)