Thymic alveolar type II epithelial mimetic cells revealed by Runx1-deficiency [CUT&Run]

Recent studies in the thymus have identified unique populations of medullary thymic epithelial cells (mTECs) called mimetic cells that transcriptionally mimic peripheral epithelial populations. These mimetic cells have been found to have important functions in the thymus in immune tolerance and the diversity and cell types represented in this pool of cells represents an active area of investigation.

Here, we utilized a mouse line with thymic specific deletion of the Runt related transcription factor 1 (Runx1) to identify a novel mimetic cell type that transcriptionally mimic alveolar type II (AT2) lung epithelial cells. Runx1 binds to genomic regions associated with epidermal growth factor receptor (EGFR) signaling suggesting a function for EGFR in regulating AT2 mTEC development.