Generation of thymic epithelial progenitor cells from induced pluripotent stem cells obtained from patients with thymic defects

Authors

• SC Pitts
• NJ Toney
• ME Gatti-Mays
• NP Tschernia
• J Strauss
• JL Gulley
• J Schlom
• RN Donahue

Abstract

Thymic epithelial cells (TECs) play a critical role in T-cell development as they provide essential cues to hematopoietic progenitors for proliferation and differentiation in the thymus. Patients with genetic mutations affecting TEC functionality present with reduced thymus development and decreased T-cell output in the periphery. We have reported that T-cell development is blocked in patients with hematopoietic-intrinsic genetic defects using an artificial thymic organoid system, but this model does not consider TEC defects. To address this, we have generated multiple induced pluripotent stem cell (iPSC) lines from patients carrying mutations on genes involved in thymic stromal development and/or function, including 22q11.2del (DiGeorge syndrome), CHD7, FOXI3, PAX1, AIRE, EXTL3, and TP63. We aim to differentiate these iPS lines into TECs and assess whether these mutations alter TEC generation. We are currently testing published protocols. However, most of these protocols focused on generating TECs from embryonic stem cells and were not optimized for human iPSCs. To address this, we are utilizing different methods to achieve a high efficiency in inducing definitive endoderm (DE), ventral pharyngeal endoderm (VPE) and finally thymic epithelial progenitors (TEP). We have already successfully reached the DE stage, as gene expression analysis by qPCR shows upregulation of genes associated with the DE and downregulation of iPS genes. Once we successfully generate TECs, we plan to incorporate them into our artificial thymic organoid system to create a model that will be solely based on human cells, obtaining a more accurate in vitro reflection of human thymic T cell development.

Scientific Focus Area: Immunology

This page was last updated on Monday, September 25, 2023