Foxp3⁺ regulatory T cells reside within the corneal epithelium and co-localize with limbal stem cells

In this study we investigated the presence of resident Foxp3⁺ regulatory T cells (Tregs) within the cornea and assessed the role of resident Tregs in corneal epithelial wound healing. Using a mouse model, we showed that in the steady state Foxp3⁺Tregs are either in close proximity or co-localize with ABCG2⁺ limbal stem cells. We also showed that these Tregs reside within the epithelial layer and not the corneal stroma. In addition, using a mouse model of mechanical injury, we demonstrated that depletion of Tregs from the cornea prior to corneal mechanical injury, using subconjunctival injection of anti-CD25, was associated with delayed epithelial healing. These results suggest a role for cornea resident Tregs in corneal epithelial cell function and wound healing and opens doors for further exploration of the role of Tregs in limbal stem cell function and survival.