title: Appearance of Birbeck granule-like structures in anti-T6 antibody-treated human epidermal Langerhans cells.
abstract: We have previously demonstrated by immunogold labeling techniques that the T6 surface antigen of living human Langerhans cells (LC) of the skin is internalized by a process of receptor-mediated endocytosis (RME). Receptor-mediated endocytosis induced by the binding of the monoclonal anti-T6 antibody BL6 involves coated pits, coated vesicles, endosomes, the smooth endoplasmic reticulum, and lysosomes. After RME, gold-labeled Birbeck granules (BGs) appear in the cell center. In the present study, by modifying the experimental conditions but retaining the presence of gold-labeled BL6, we have observed (in addition to the above-mentioned gold-labeled organelles) images that appear to correspond to BG-like structures. These structures, like the intracytoplasmic BGs, are pentalaminar and gold-labeled, but they differ from the intracytoplasmic BGs by their attachment to the cell membrane, their length, the frequent presence of a coat, and by prolongation by one or more coated pits. Birbeck granule-like structures seem to result, at the ultrastructural level, from receptor ligand interactions and from modifications of the LC shape.
authors.affiliation: INSERM U.311, Université Louis Pasteur, France.
authors.forename: D
authors.initials: D
authors.lastname: Hanau
authors.forename: M
authors.initials: M
authors.lastname: Fabre
authors.forename: D A
authors.initials: DA
authors.lastname: Schmitt
authors.forename: J C
authors.initials: JC
authors.lastname: Garaud
authors.forename: G
authors.initials: G
authors.lastname: Pauly
authors.forename: J P
authors.initials: JP
authors.lastname: Cazenave
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D006046:Gold; D006801:Humans; D007801:Langerhans Cells / Q000648:ultrastructure*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D006046:Gold