[Langerin: a new lectin specific for Langerhans cells induces the formation of Birbeck granules].

Generation of monoclonal antibodies restricted to human dendritic cells generated from CD34+ hematopoietic precursors has enabled the identification of Langerin, a Ca(++)-dependent type II lectin. Only expressed by Langerhans cells, Langerin is responsible for Birbeck granule formation by membrane superimposition and zippering. Furthermore, cell-surface Langerin is rapidly internalized into Birbeck granules, and does not colocalize with MHC class II rich compartments. Langerin gene transfected into mouse fibroblasts induces the formation of Birbeck granule-like structures, that would permit a better understanding of the function of Birbeck granules.