Biology subjects

North, T. E.

Publications and source records attributed to North, T. E..

4 recordsLinked to original sources

bioRxiv2026

Efficient Generation of Functional TCRαβ+ Cytotoxic T Cells from hiPSCs via Small-Molecule Modulation

Genetically engineered human induced pluripotent stem cells (hiPSCs) represent a promising platform for regenerative medicine and next-generation immunotherapies. While recent advances enable stroma-free differentiation of hiPSCs into mature CD3TCR{beta} cytotoxic T lymphocytes (CTLs), overall efficiency remains limited. Here, we identify small-molecule modulators that enhance T cell output, particularly at the ProT cell stage. Targeted and stage-specific inhibition of AHR, DOT1L, or GSK3 drives robust maturation from ProT to CD4 immature single-positive (ISP) cells, markedly increasing CD4CD8 populations and augmenting CTL production of up to 2000 fold. hiPSC-derived T (iT) cells matured under these conditions display superior activity in cytotoxicity assays using AMG-701 (BCMAxCD3) or Blinatumomab (CD19xCD3). These effects were reproducible across independent hiPSC lines, diverse hematopoietic progenitor generation methods, and multiple stroma-free differentiation platforms, and were further validated in cord blood CD34 cells. Notably, AHR inhibition enhanced T cell development and promoted B lymphopoiesis, revealing shared regulatory pathways in lymphoid lineage specification. We also demonstrate that the Oct4-activating compound OAC1 functions as a weak AHR inhibitor, partially recapitulating the effects of canonical AHR blockers in both cellular and zebrafish AHR reporter systems. Collectively, our findings define key molecular circuits governing human lymphoid differentiation and establish practical strategies to optimize the yield and function of hiPSC-derived cytotoxic T cells. This work advances the development of both universal and autologous hiPSC-derived T cell therapies, offering a path forward even for patient-specific hiPSC lines with suboptimal T cell differentiation potential.

cell biology↗

bioRxiv2025

RNA Editors Sculpt the Transcriptome During Terminal Erythropoiesis

Selective RNA degradation during terminal erythropoiesis results in a globin-rich transcriptome in mature erythrocytes, but the specific RNA decay pathways remain unknown. We found that deficiency of the terminal uridylyl transferase enzyme Zcchc6 and the 3-5 exoribonuclease Dis3l2 in mouse models led to fetal and perinatal reticulocytosis, an accumulation of RNA-rich precursors of terminal erythroid cells, suggesting their crucial roles in terminal red cell differentiation. Notably, knockout embryos exhibited persistent high-level expression of Hbb-bh1 globin, the ortholog of human fetal{gamma} -globin. Perturbation of the Zcchc6-Dis3l2 pathway in mice engineered to express the human {beta}-globin locus likewise increased{gamma} -globin levels in fetal erythroid cells, suggesting that globin switching entails post-transcriptional mechanisms of mRNA destabilization in addition to transcriptional down-regulation. We cultured human hematopoietic stem and progenitor cells (HSPCs), performed CRISPR/Cas9-mediated knockout of ZCCHC6 and DIS3L2, and observed accumulation of RNA and elevated {gamma}-globin levels in terminal erythroid cells. Our findings reveal a conserved role for the ZCCHC6/DIS3L2 RNA editors in terminal erythropoiesis and demonstrate a post-transcriptional mechanism for{gamma} -globin gene switching, advancing research into in vitro erythrocyte generation and{gamma} -globin stabilization to ameliorate hemoglobinopathies.

developmental biology↗

bioRxiv2024

Bnip3lb-driven mitophagy sustains expansion of the embryonic hematopoietic stem cell pool

Embryonic hematopoietic stem and progenitor cells (HSPCs) have the unique ability to undergo rapid proliferation while maintaining multipotency, a clinically-valuable quality which currently cannot be replicated in vitro. Here, we show that embryonic HSPCs achieve this state by precise spatio-temporal regulation of reactive oxygen species (ROS) via Bnip3lb-associated developmentally-programmed mitophagy, a distinct autophagic regulatory mechanism from that of adult HSPCs. While ROS drives HSPC specification in the dorsal aorta, scRNAseq and live-imaging of Tg(ubi:mitoQC) zebrafish indicate that mitophagy initiates as HSPCs undergo endothelial-to-hematopoietic transition and colonize the caudal hematopoietic tissue (CHT). Knockdown of bnip3lb reduced mitophagy and HSPC numbers in the CHT by promoting myeloid-biased differentiation and apoptosis, which was rescued by anti-oxidant exposure. Conversely, induction of mitophagy enhanced both embryonic HSPC and lymphoid progenitor numbers. Significantly, mitophagy activation improved ex vivo functional capacity of hematopoietic progenitors derived from human-induced pluripotent stem cells (hiPSCs), enhancing serial-replating hematopoietic colony forming potential. HIGHLIGHTSO_LIROS promotes HSPC formation in the dorsal aorta but negatively affects maintenance thereafter. C_LIO_LIHSPCs colonizing secondary niches control ROS levels via Bnip3lb-directed mitophagy. C_LIO_LIMitophagy protects nascent HSPCs from ROS-associated apoptosis and maintains multipotency. C_LIO_LIInduction of mitophagy enhances long-term hematopoietic potential of iPSC-derived HSPCs. C_LI

cell biology↗

bioRxiv2024

Design of a Soluble Multivalent Notch Agonist

Designed protein agonists can enhance the efficiency of endogenous signaling pathways, and provide a powerful means to control cellular functions and develop disease therapeutics. Designing a soluble cytokine-like agonist for Notch signaling, an evolutionarily conserved pathway that regulates cell fate in embryonic and adult development, is especially challenging because Notch receptor activation requires a mechanical force that is typically mediated by cell-associated transmembrane ligands at sites of cell-cell contact. Moreover, free soluble Notch ligand is signal inhibitory. Here, we exploit computationally designed protein oligomers with precise geometries and valencies to generate cytokine-like, protein only, multivalent soluble Notch agonists. These tools promote cell-cell contact, cluster Notch proteins in synapses at the cell surface, and activate Notch signaling in reporter cell lines and cells expressing endogenous receptors. We demonstrate the utility of these soluble Notch agonists in T cell differentiation from cord blood (CB) and human induced pluripotent stem cells (iPSCs), and in bioreactor production of T cells in liquid suspension. Soluble multivalent Notch agonists can be applied broadly to in vitro cellular differentiation methods to generate clinical cell products and to develop immunotherapies.

synthetic biology↗