Generation of Artificial Thymic Organoids from Human and Murine Hematopoietic Stem and Progenitor Cells.

The generation of T cells is a complex, carefully orchestrated process that occurs in the thymus. The ability to mimic T cell differentiation in vitro has opened up avenues to better understand different stages of thymopoiesis but has also enabled the in vitro production of mature T cells suitable for immunotherapy. Among existing protocols, the artificial thymic organoid (ATO) system has been shown to be the most efficient at producing mature conventional T cells. In this serum-free model, human or murine hematopoietic stem and progenitor cells (HSPCs) are combined with a murine stromal cell line expressing a Notch ligand in a 3D cell aggregate. In ATOs, although only simple medium changes are required throughout the cultures, HSPCs differentiate into T cells with kinetics and phenotypes similar to those of endogenous thymopoiesis. This article describes protocols for the generation of ATOs from human and murine HSPCs. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Expansion and preparation of MS5-hDLL4 or MS5-mDLL4 cells Basic Protocol 2: Isolation of human hematopoietic stem and progenitor cells (HSPCs; CD34+ cells) Support Protocol 1: Transduction of human HSPCs (CD34+ cells) Basic Protocol 3: Production of thymic progenitors and mature T cells from human HSPCs in artificial thymic organoids (ATOs) Support Protocol 2: Phenotype analysis of human ATO cells by flow cytometry Basic Protocol 4: Isolation of murine HSPCs (Lin- Sca1+ cKit+; LSK) and hematopoietic stem cells (LSK CD150+ CD48-) Basic Protocol 5: Production of thymic progenitors and mature T cells from murine HSPCs in ATOs Support Protocol 3: Phenotype analysis of murine ATO cells by flow cytometry Alternate Protocol: Generation of ATOs from single HSPCs.