Mechanisms regulating skin immunity and inflammation

Immune homeostasis in the skin requires dynamic crosstalk between epithelial, stromal and immune cells, which is influenced by environmental insults and commensal microorganisms. Here, the authors highlight recent studies that provide an insight into the immunoregulatory mechanisms that mediate host defence and prevent chronic inflammation in the skin. Immune responses in the skin are important for host defence against pathogenic microorganisms. However, dysregulated immune reactions can cause chronic inflammatory skin diseases. Extensive crosstalk between the different cellular and microbial components of the skin regulates local immune responses to ensure efficient host defence, to maintain and restore homeostasis, and to prevent chronic disease. In this Review, we discuss recent findings that highlight the complex regulatory networks that control skin immunity, and we provide new paradigms for the mechanisms that regulate skin immune responses in host defence and in chronic inflammation.