PLX148564

GSE103420: Respecifying human iPSC-derived blood cells into highly engraftable hematopoietic stem and progenitor cells with a single factor

• Organsim human
• Type RNASEQ
• Target gene
• Project ARCHS4

Purpose: We designed this study to evaluate the feasibility of using only one factor to respecify human induced pluripotent stem cells (iPSCs)-derived blood cells into long-term engraftable hematopoietic stem and progenitor cells (HSPCs).; We also parallelly compared iPSC-derived HSPCs (iHSPCs) with primary HSPCs under the same induction and transplantation condition in order to examine the functional equivalency between iHSPCs and bona fide HSPCs.; ; Methods: In vitro derived human iPSC-HSPCs are induced with or without (w/o) doxycycline for the expression of MLL-AF4. In vivo derived bone marrow cells are harvested and FACS-sorted for human populations from primary transplants over nine to sixteen weeks after transplantation. Either iPSC-HSPCs or primary HSPCs, both of which are induced by MLL-AF4, is used for the transplantation experiments. iPSCs are either derived from peripheral blood mobilized CD34+ HSPCs (CD34-iPSC) or mononuclear cells (MN-iPSCs). Normal human CD34+ HSPCs and mononuclear cells are set as control groups.; ; Results: MLL-AF4 can impart HSC and lymphoid potential to iPSC-derived blood cells in vitro, and induction of MLL-AF4 leads to the cellular identity transition from common myeloid progenitors to hematopoietic stem and progenitor cells. MLL-AF4 alone is sufficient to realize the potent engraftment of induced HSPCs (iHSPCs) from iPSCs, and multilineage and long-term hematopoiesis could be observed. Primary HSPCs with the induction of MLL-AF4 could gain significantly enhanced engraftability. During the long-term engraftment period, leukemic mutations with a bias to B-cell leukemia could be found in the iHSPCs and their derivatives. By contrast, MLL-AF4 induced primary HSPCs maintain the normal hematopoiesis without leukemic transformation.; ; Conclusions: Our study has demonstrated for the first time, to our knowledge, that the pluripotency-dependent conversion of somatic cells to long-term engraftable HSPCs can be achieved by using a single factor in a non-integrative way. This study also suggests that iPSC-derived HSPCs are more prone to leukemic mutations during the long-term engraftment period, which provides a necessary caveat of using them in the actual therapies. ; SOURCE: Yuet Wai KanYuet Wai Kan University of California, San Francisco