Langerhans cells (LCs) are antigen-presenting dendritic cells (DCs) that reside in epithelia. The best studied example is the LC of the epidermis. By electron microscopy, their identifying feature is the unique rod- or tennis racket-shaped Birbeck granule. The phenotypic hallmark is their expression of the C-type lectin receptor langerin/CD207. Langerin, however, is also expressed on a recently discovered population of DC in the dermis and other tissues of the body. These 'dermal langerin+ dendritic cells' are unrelated to LCs. The complex field of langerin-negative dermal DCs is not dealt with here. In this article, we briefly review the history, ontogeny, and homeostasis of LCs. More emphasis is laid on the discussion of functional properties in vivo. Novel models using genetically engineered mice are contributing tremendously to our understanding of the role of LCs in eliciting adaptive immune responses against pathogens or tumors and in inducing and maintaining tolerance against self antigens and innocuous substances in vivo. Also, innate effector functions are increasingly being recognized. Current activities in this area are reviewed, and possibilities for future exploitation of LC in medicine, e.g. for the improvement of vaccines, are contemplated.

Antigen presentation, CD103 antigen, CD34 antigen, CD40 antigen, CD45 antigen, CD8 antigen, CD86 antigen, Cell ablation, Dendritic cells, Fc receptor, HLA DR antigen, Ikaros transcription factor, Immunogenicity, Langerhans cell, Langerhans cells, Langerin/CD207, adaptive immunity, adenosine triphosphatase, antigen antibody reaction, antigen expression, antigen presentation, atopic dermatitis, autoantigen, cell function, cell granule, cell lineage, cell maturation, cell population, cell proliferation, cell specificity, cell structure, cell subpopulation, cell surface, cellular distribution, cellular immunity, chemokine, chemokine receptor CCR7, colony stimulating factor 1, colony stimulating factor receptor, cytotoxic T lymphocyte, dendritic cell, diphtheria toxin, drug efficacy, drug targeting, effector cell, electron microscopy, enzyme activity, epidermis, epithelial cell adhesion molecule, gene deletion, genetic engineering, glycoprotein p 15095, gold chloride, histiocytosis X, history of medicine, homeostasis, human, hypersensitivity, immune system, immunogenicity, immunological tolerance, in vivo study, inhibitor of differentiation 2, innate immunity, interleukin 10, langerin, leukocyte, lymphoid organ, major histocompatibility antigen class 2, medical research, mononuclear phagocyte, nonhuman, ontogeny, priority journal, protein antibody, protein expression, reticuloendotheliosis, review, skin cell, t6 antigen, transcription factor RelB, transforming growth factor beta, tumor immunity, tumor model, tumor vaccine, unindexed drug, vaccination, vaccine, virus infection,
Immunological Reviews
Erasmus MC: University Medical Center Rotterdam

Romani, N, Clausen, B.E, & Stoitzner, P. (2010). Langerhans cells and more: Langerin-expressing dendritic cell subsets in the skin. Immunological Reviews (Vol. 234, pp. 120–141). doi:10.1111/j.0105-2896.2009.00886.x