Tissue Resident Foxp3+ Regulatory T Cells: Sentinels and Saboteurs in Health and Disease

The document discusses the role of Foxp3+ Regulatory T Cells (Tregs) in health and disease. Tregs, which include thymus-derived tTreg and peripherally induced pTreg cells, are crucial for maintaining immunity and tolerance. They are found in various tissues, including the skin, lungs, and visceral adipose tissue (VAT). In the skin, Tregs are involved in hair follicle regeneration and wound healing, and their function may be affected by high-fat diets, potentially leading to hair loss. In VAT, Tregs regulate inflammatory responses in obesity-associated metabolic diseases, but their number is significantly reduced in obese patients. The document also discusses the role of Tregs in diseases like systemic sclerosis, COVID-19, and muscle repair. In the context of hair growth, Tregs facilitate epithelial stem cell differentiation, essential for hair growth. However, obesity can accelerate hair thinning through stem cell-centric converging mechanisms. The document concludes that more research is needed to understand the mechanisms involved in Treg retention within tissues and the role of local tissue antigen stimulation in maintaining Tregs.