UM171 expands distinct types of myeloid and NK progenitors from human pluripotent stem cells

Abstract

Scaling up blood cell production from hPSCs is critical to advancing hPSC technologies for blood transfusion, immunotherapy, and transplantation. Here we explored the potential of the HSC agonist pyrimido-indole derivative UM171, to expand hematopoietic progenitors (HPs) derived from hPSCs in chemically defined conditions. We revealed that culture of hPSC-HPs in HSC expansion conditions (SFEM with added TPO, SCF, FLT3L, IL3 and IL6) in the presence of UM171 predominantly expanded HPs with a unique CD34 + CD41a lo CD45 + phenotype that were enriched in granulocytic progenitors (G-CFCs). In contrast, in lymphoid cultures on OP9-DLL4, in the presence of SCF, FLT3L, and IL7, UM171 selectively expanded CD34 + CD45 + CD7 + lymphoid progenitors with NK cell potential, and increased NK cell output up to 10-fold. These studies should improve our understanding of the effect of UM171 on de novo generated HPs, and facilitate development of protocols for robust granulocyte and lymphoid cell production from hPSCs, for adoptive immunotherapies.

Effective and Rapid Generation of Functional Neutrophils from Induced Pluripotent Stem Cells Using ETV2-Modified mRNA

“…Similarly, withdrawal of FGF2 reduced blood production in ETV2-induced cultures (Figure 2G). To test whether myeloid cell production can be improved with the use of other cytokines or small molecules, we tested the effects of FLT3L, SCF, and small-molecule UM171, which has been shown to stimulate expansion of human cord blood CD34 + cells ex vivo (Fares et al., 2014) and hPSC-derived myeloid progenitors enriched in G-CFCs (Mesquitta et al., 2019). We have found that the presence of SCF and FLT3L slightly decreased the number of collected floating cells during differentiation, while UM171 had no significant effect on the number of hematopoietic cells.…”

New Insights into Hematopoietic Stem Cell Expansion to Stimulate Repopulation of the Adult Blood System for Transplantation

“…Further, UM171 can act as a new substance to expand HSCs without the risk of chronic graft-versus-host disease (GVHD) and relapse [ 32 , 33 ]. Moreover, UM171 plays an important role in treating lymphoma [ 60 , 61 ]. A study explored the culture of hPSC-HPs in HSC expansion conditions.…”

iPSC-Derived Natural Killer Cells for Cancer Immunotherapy

“…ESC-NK exerted good functional characteristics including cytokine production and cytolytic activity in vitro and in vivo against tumor cells ( Woll et al, 2005 ; 2009 ). Other groups have replaced the second stromal line with genetically engineered feeder cells expressing Notch ligand DLL1 or DLL4, which promote the expansion of HPCs with a bias for NK lineage ( Mesquitta et al, 2019 ; Zeng et al, 2017 ).…”

“…In general, small molecules reduce the cost of product development while maintaining or even increasing the NK cell differentiation efficiency. For example, the Slukvin team showed that UM171, an HSC-agonist pyrimido-indole derivative, selectively promotes the expansion of a lymphoid progenitor population that has a 10-fold propensity for NK cell differentiation ( Mesquitta et al, 2019 ).…”