Antigen receptor-redirected T cells derived from hematopoietic precursor cells lack expression of the endogenous TCR/CD3 receptor and exhibit specific antitumor capacities

ABSTRACT

Recent clinical studies indicate that adoptive T-cell therapy and especially chimeric antigen receptor (CAR) T-cell therapy is a very potent and potentially curative treatment for B-lineage hematologic malignancies. Currently, autologous peripheral blood T cells are used for adoptive T-cell therapy. Adoptive T cells derived from healthy allogeneic donors may have several advantages; however, the expected occurrence of graft versus host disease (GvHD) as a consequence of the diverse allogeneic T-cell receptor (TCR) repertoire expressed by these cells compromises this approach. Here, we generated T cells from cord blood hematopoietic progenitor cells (HPCs) that were transduced to express an antigen receptor (AR): either a CAR or a TCR with or without built-in CD28 co-stimulatory domains. These AR-transgenic HPCs were culture-expanded on an OP9-DL1 feeder layer and subsequently differentiated to CD5⁺CD7⁺ T-lineage precursors, to CD4⁺ CD8⁺ double positive cells and finally to mature AR⁺ T cells. The AR⁺ T cells were largely naive CD45RA⁺CD62L⁺ T cells. These T cells had mostly germline TCRα and TCRβ loci and therefore lacked surface-expressed CD3/TCRαβ complexes. The CD3⁻ AR-transgenic cells were mono-specific, functional T cells as they displayed specific cytotoxic activity. Cytokine production, including IL-2, was prominent in those cells bearing ARs with built-in CD28 domains. Data sustain the concept that cord blood HPC derived, in vitro generated allogeneic CD3⁻ AR⁺ T cells can be used to more effectively eliminate malignant cells, while at the same time limiting the occurrence of GvHD.

KEYWORDS:

• Chimeric antigen receptor
• cord blood
• hematopoietic precursor cell
• hematopoietic stem cell
• immunotherapy
• T cell

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.

Acknowledgments

The authors would like to thank Dr. Katrien Francois, Department of Cardiac Surgery and Dr. Conny Matthys, Cord Blood Bank of Ghent University Hospital for providing thymus and cord blood samples. Finally, we would like to thank Dr. Tom Boterberg for irradiation of the feeder cells and Sophie Vermaut for help with flow cytometry and cell sorting.

Funding

This work was supported by the Kinderkankerfonds, Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek Vlaanderen, FWO), Stichting tegen Kanker, the “Interuniversity Attraction Poles” (IAP) Program of the Belgian Science Policy Office (BELSPO) and the Fonds National de la Recherche Scientifique (FNRS). SV, YVC and GV are supported by the Instituut voor de Aanmoediging van Innovatie door Wetenschap en Technologie in Vlaanderen (IWT). SD and TK are supported by the FWO and PT is supported by the FNRS (Télévie).