Next, to create more homogenous populations of NPCs that were enriched for CNS progenitors the initially mixed NPC cultures were immunopurified using a four color, fluorescence activated cell sorting (FACS) protocol designed to remove non-neural cells and cells expressing CD271 (p75; NGFR), a marker of neural crest cells that produce PNS cells and select for CD184 (CXC chemokine receptor-4 (CXCR4)) expression as a marker of CNS progenitors. (Fig. 2B, Sup. Fig. 6)36. Whereas self-renewing, CD184+/CD271−/CD24+/CD15+ cells capable of expansion for more than five passages could be readily established from both the mother and father, neural induction of iPSCs from both BD patients repeatedly produced more PNS progenitors than CNS progenitors as defined by immunostaining for CD271 and CD184 markers, respectively (Sup. Fig. 7). Consistent with this phenotype, despite repeated attempts under varied neural induction conditions, CD184+/CD271−/CD24+/CD15+ immunopurified NPC lines could only be successfully established beyond five passages from a subset of the BD-patient iPSC lines. Of the successfully FACS-purified NPC lines expressing CD184+, all had characteristic NESTIN+ cell morphology, proliferated in a monolayer in the presence of EGF and bFGF,
