Int J Stem Cells.  2025 Feb;18(1):1-11. 10.15283/ijsc23107.

Immune-Epithelial Cell Interactions during Epidermal Regeneration, Repair, and Inflammatory Diseases

• Schmitter-Sánchez AD
• Park S

• KMID: 2565192
• DOI: http://doi.org/10.15283/ijsc23107

Abstract

The multiple layers of the skin cover and protect our entire body. Among the skin layers, the epidermis is in direct contact with the outer environment and serves as the first line of defense. The epidermis functions as a physical and immunological barrier. To maintain barrier function, the epidermis continually regenerates and repairs itself when injured. Interactions between tissue-resident immune cells and epithelial cells are essential to sustain epidermal regeneration and repair. In this review, we will dissect the crosstalk between epithelial cells and specific immune cell populations located in the epidermis during homeostasis and wound repair. In addition, we will analyze the contribution of dysregulated immune-epithelial interactions in chronic inflammatory diseases.

Keyword

Epidermis; Keratinocytes; Dendritic cells; Cell communication; Wound healing; Skin diseases

Figure

• 

  Fig. 1 Communication between keratinocytes and tissue-resident immune cells in epidermal homeostasis. Keratinocytes contribute to the recruitment of Langerhans cells (LCs), dendritic epidermal T cells (DETCs), and innate lymphoid cells (ILCs). In addition, keratinocytes retain LC, DETC and tissue-resident memory T (TRM) cell populations by promoting their survival in the epidermis. LCs epidermal presence is also maintained by downregulation of their migration and activation by keratinocyte-derived signaling. DETCs downregulate keratinocyte apoptosis to promote homeostasis. IGF-1: insulin-like growth factor 1, IL: interleukin, CCL: chemokine (C-C motif) ligand, TGF: transforming growth factor, BMP: bone morphogenetic protein, TSLP: thymic stromal lymphopoietin, TCR: T-cell receptor.

• 

  Fig. 2 Keratinocytes and tissue-resident immune cells cooperate during wound repair. Dendritic epidermal T cells (DETCs) and innate lymphoid cells (ILCs) promote wound repair by upregulating the proliferation and migration of keratinocytes. In return, damaged keratinocytes recruit ILCs and activate DETCs. Keratinocytes can regulate the immune response by recruiting Langerhans cells (LCs) and promoting their migration and immunotolerance. CCL: chemokine (C-C motif) ligand, IL: interleukin, KGF: keratinocyte growth factor, TNF: tumor necrosis factor.

Reference

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