Generation of functional hematopoietic stem and progenitor cells (HSPCs) from human pluripotent stem cells (PSCs) has been a long-sought-after goal for use in hematopoietic cell production, disease modeling, and eventually transplantation medicine. Homing of HSPCs from bloodstream to bone marrow (BM) is an important aspect of HSPC biology that has remained unaddressed in efforts to derive functional HSPCs from human PSCs. We have therefore examined the BM homing properties of human induced pluripotent stem cell–derived HSPCs (hiPS-HSPCs). We found that they express molecular effectors of BM extravasation, such as the chemokine receptor CXCR4 and the integrin dimer VLA-4, but lack expression of E-selectin ligands that program HSPC trafficking to BM. To overcome this deficiency, we expressed human fucosyltransferase 6 using modified mRNA. Expression of fucosyltransferase 6 resulted in marked increases in levels of cell surface E-selectin ligands. The glycoengineered cells exhibited enhanced tethering and rolling interactions on E-selectin–bearing endothelium under flow conditions in vitro as well as increased BM trafficking and extravasation when transplanted into mice. However, glycoengineered hiPS-HSPCs did not engraft long-term, indicating that additional functional deficiencies exist in these cells. Our results suggest that strategies toward increasing E-selectin ligand expression could be applicable as part of a multifaceted approach to optimize the production of HSPCs from human PSCs.
Jungmin Lee, Brad Dykstra, Joel A. Spencer, Laurie L. Kenney, Dale L. Greiner, Leonard D. Shultz, Michael A. Brehm, Charles P. Lin, Robert Sackstein, Derrick J. Rossi
Usage data is cumulative from July 2018 through July 2019.
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.