Abstract: Disclosed herein is a system and method for producing T cells from stem cell populations. Specifically exemplified herein is a culture system and method that produces CD4 cells and/or T cell subtypes from a CD4 lineage using a sample of hematopoietic stem cells. Adult hematopoietic precursor/stem cells (HPC) are progenitors to all lineages of immune cells. There has been limited success in generating functional CD4 T cells with this convenient culture system. Also disclosed herein is a novel stromal cell line expressing DL1, interleukin-7 (IL-7), and FMS-like tyrosine kinase 3 ligand (Flt3-L). This improved culture system can greatly facilitate the study of late T cell development and enables immunotherapeutic applications.