Skin-resident immune cells actively coordinate their distribution with epidermal cells during homeostasis

Park et al. (MedRxiv) DOI: 10.1101/2021.01.08.425932



  • Skin immunology

  • Immune cell distribution

  • Immune-epithelial crosstalk


Main Findings

​Park et al investigated the interaction of immune cells and epithelial cells during homeostasis. In order to track different cell types over time in vivo, they generated a mouse line which labelled the three main cell types resident in the skin; Langerhans cells (LCs), dendritic epidermal T cells (DTECs) and epithelial cells. Using an established in vivo imaging approach, they uncovered that epithelial cells regulate immune cell composition in the epidermis. LCs and DTECs reside in the basal layer of the epidermis and maintain their position in a non-random tiling pattern. The GTPase Rac1 plays a crucial role in LCs to maintain their positional stability, density and tiling pattern. 


  • How exactly the epithelial cells regulate LC and DTEC distribution remains unknown

  • Whether or not Rac1 plays a similar role in DTECs


Discerning the interaction of immune cells with epithelial cells in vivo and in real time offers new tools in visualising and understanding the establishment of homeostasis


Tools established might be used in other systems and lay the ground for further examinations into mechanisms and behaviour in non-homeostatic conditions.


Reviewed by Dorothée Berthold as part of the cross-institutional journal club of the Immunology Institute of the Icahn School of Medicine, Mount Sinai and the Kennedy Institute of Rheumatology, University of Oxford.