Generation of Tumor Antigen-Specific iPSC-Derived Thymic Emigrants (iTE) using a Novel 3D Thymic Culture System

Induced Pluripotent Stem Cell (iPSC)-derived T cells may provide future therapies for cancer patients, but those generated by current methods, such as the OP9/DLL1 system, have shown abnormalities that pose major barriers for clinical translation. Our data indicate that these iPSC-derived CD8 single positive T cells are more similar to CD4+CD8+ double positive T cells than to mature naïve T cells, display markers of developmental arrest and exhibit characteristics of innate-like immune cells. We developed a 3D organ culture method which avoids these aberrant developmental fates, and generates a novel homogenous subset of CD8aß+ antigen-specific T cells, iPSC-derived Thymic Emigrants (iTE). iTE exhibit phenotypic and functional similarities to naïve T cells both in vitro and in vivo, including an enormous capacity for expansion, memory formation and tumor suppression. These data illustrate the limitations of current methods and provide a blueprint for the generation of antigen-specific iTE with tremendous clinical potential. Overall design: Comparison of iPSC-derived Thymic Emigrants vs. Extrathymic T cells generated on OP9/DLL1 system