{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Langerin (CD207) is a type II transmembrane cell surface receptor produced by Langerhans cells (LCs), which are immature dendritic cells of the epidermis and mucosa. Langerin is localized in the Birbeck granules, organelles with superimposed and zippered membranes, present in the cytoplasm of LCs. Langerin is a C-type lectin capable of binding to a variety of carbohydrates, such as high-mannose structures on viral envelope glycoproteins and mannan and β-glucan on fungal cell walls. The binding of carbohydrates leads langerin to internalize antigen into the Birbeck granules and provides access to a nonclassical antigen-processing pathway. Langerin protein expression has utility in differentiating Langerhans cell histiocytosis from other non-Langerhans cell histiocytic proliferations."}]}]}