Skin immune sentinels in health and disease

• Published in: Nature reviews. Immunology Vol. 9; no. 10; pp. 679 - 691
• Main Authors: Nestle, Frank O, Di Meglio, Paola, Qin, Jian-Zhong, Nickoloff, Brian J
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.10.2009; Nature Publishing Group
• Subjects: Animals; Biomedical and Life Sciences; Biomedicine; Dendritic cells; Dendritic Cells - immunology; Dendritic Cells - metabolism; Dermatitis - immunology; Dermatitis - metabolism; Fibroblasts; Genetic aspects; Health aspects; Homeostasis; Humans; Immune response; Immune system; Immunity, Innate; Immunology; Keratinocytes; Keratinocytes - immunology; Keratinocytes - metabolism; Lymphocytes; Macrophages - immunology; Macrophages - metabolism; Pathogens; Pathology; Physiological aspects; Psoriasis - immunology; Psoriasis - metabolism; review-article; Risk factors; Sensors; Skin; Skin - anatomy & histology; Skin - immunology; Skin - metabolism; Skin diseases; T cell receptors; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - metabolism; United Kingdom
• ISSN: 1474-1733; 1474-1741
• DOI: 10.1038/nri2622

Key Points Human skin and the immune cells that it contains provide essential protection of the human body from injury and infection. Keratinocytes are a first line of defence and sense danger through alert systems such as the inflammasome and Toll-like receptors. They mediate an inflammatory response by secreting pro-inflammatory cytokines. A subpopulation of CD103 + dendritic cells is strategically positioned for cross-presentation of skin-tropic pathogens. Recent data have highlighted a key role of tissue-resident rather than circulating T cells in skin homeostasis and pathology. Important lessons for human skin immunology have been learnt from immunologically targeted therapies in inflammatory skin disorders such as psoriasis. The skin and the immune cells that it contains provide essential protection from injury and infection. This Review describes recent studies that expand our understanding of the functional role of these sentinel cells in sensing danger and mediating homeostasis and disease in the skin. Human skin and its immune cells provide essential protection of the human body from injury and infection. Recent studies reinforce the importance of keratinocytes as sensors of danger through alert systems such as the inflammasome. In addition, newly identified CD103 + dendritic cells are strategically positioned for cross-presentation of skin-tropic pathogens and accumulating data highlight a key role of tissue-resident rather than circulating T cells in skin homeostasis and pathology. This Review focuses on recent progress in dissecting the functional role of skin immune cells in skin disease.