generated lymphoid progenitors encompass both T cell and innate lymphoid cell fates.

Introduction: We previously established a feeder-free cell therapy platform for the generation of lymphoid-primed progenitors using immobilized Delta-like ligand 4 (DLL4). studies demonstrated that adoptive transfer of these progenitors accelerates T cell reconstitution following thymic engraftment.

Method: To further explore the full therapeutic potential of this cell product, we performed a comprehensive molecular and phenotypic characterization using single cell RNA sequencing and mass cytometry analysis.

Results: Our analysis revealed the presence of distinct cell subsets within the cellular product characterized mainly by commitment to lymphoid lineages. Using integrated transcriptomic analyses to compare these -generated progenitors to human thymocytes, we revealed strong similarities with early stages of T cell development, underscoring the physiological relevance of our system. We also delineated two distinct developmental trajectories within the CD7 progenitor population: a T cell-oriented path, marked by CD5 upregulation, and an innate lymphoid cell (ILC)-oriented branch, identified by CD161 expression and an ILC-like gene signature. Despite these lineage predispositions, both subsets demonstrated plasticity, retaining the ability to differentiate into both T cells and natural killer (NK) cells . Additionally, in our experimental setting, we observed that BCL11B, a transcription factor essential for T cell commitment, regulates negatively myeloid cell differentiation while preserving the potential for NK cell development.

Conclusion: These findings underscore the versatility of DLL4-based lymphoid progenitors in generating either T cells or ILCs in response to environmental cues. This research paves the way for innovative cell therapy approaches to treat immune deficiencies and cancer- and age-related immune dysfunctions.