Langerin

CD207, langerin (Cluster of Differentiation 207) is a is_associated_with::protein which in humans is encoded by the CD207 is_associated_with::gene. Langerin is a type II transmembrane, is_associated_with::C-type lectin receptor on is_associated_with::Langerhans cells.

Function
The protein encoded by this gene is expressed in is_associated_with::Langerhans cells which are immature dendritic cells of the epidermis and is_associated_with::mucosa. Additionally it is known by the name C-type lectin domain family 4 member K (CD antigen CD207). It is also expressed in several other dendritic cell types including dermal CD103+ DCs and splenic CD8+ DCs. Langerin is localized in the is_associated_with::Birbeck granules, organelles present in the is_associated_with::cytoplasm of Langerhans cells and consisting of superimposed and zippered membranes. It is a C-type is_associated_with::lectin with mannose binding specificity, and it has been proposed that is_associated_with::mannose binding by this protein leads to internalization of antigen into Birbeck granules and providing access to a nonclassical antigen-processing pathway.

Clinical significance
Langerin on mucosal Langerhans cells of the human genital is_associated_with::epithelium binds to is_associated_with::HIV-1 and subsequently internalizes it into is_associated_with::Birbeck granules to be degraded.