Scientists have identified a signal in mice that recruits immune cells to chronically inflamed skin, according to a report published this week in Nature Immunology. The research could lead to the development of treatments for common skin allergies such as dermatitis.
Some skin allergies are characterized by an influx of two types of white blood cells, known as T cells and eosinophils. Andrew Luster and colleagues report that a protein called CCL8 produced in allergen-inflamed skin can lead to a chronic form of dermatitis by attracting the white blood cells that express CCR8, a receptor that recognizes CCL8. These T cells produce copious amounts of the molecule interleukin 5 (IL-5), which recruits the eosinophils and exacerbates the allergic inflammation. The team notes that mice lacking either CCL8 or CCR8 display much less eosinophilic infiltration and less severe skin disease.
The authors also find human CCR8+ T cells are enriched for IL-5 expression. Blocking CCR8 function might be a useful method for providing relief to humans with skin allergies.