title: An immuno-electron microscopic study on interactions among dendritic cells, macrophages and lymphocytes in the human palatine tonsil.
abstract: The sites of interaction between antigen-presenting cells (dendritic cells, macrophages) and lymphocytes in the human palatine tonsil were investigated by pre-embedding immuno-electron microscopy and acid-phosphatase histochemistry. Used in this study were: an S-100 protein antiserum recognizing Langerhans cells and interdigitating cells, OKT6 monoclonal antibody reacting with surface antigens of Langerhans cells, and Leu-3a monoclonal antibody directed to surface antigens of helper-T-cells. In the stratified squamous epithelium, Langerhans cells with characteristic rod-shaped or racket-shaped Birbeck granules exhibited S-100 protein and OKT6 immunoreactivites, and frequently extended long processes to adjacent lymphocytes. The subepithelial area contained a significant number of macrophages, some of which were closely apposed to interdigitating cells with S-100 protein immunoreactivity. Occasionally, macrophages with acid-phosphatase-positive phagosomes and/or lysosomes extended short processes to neighboring lymphocytes. In the interfollicular area, some interdigitating cells and a few Langerhans cells were seen in proximity to or in contact with lymphocytes stained with the Leu-3a antibody. These findings support previous in vitro studies suggesting the induction of T-cell activation by antigen-presenting cells. They further indicate that T-cell activation by the individual antigen-presenting cells takes place in different areas of the human palatine tonsil through a variety of cell-to-cell interactions.
authors.affiliation: Department of Otolaryngology, Osaka Medical College, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Okato
authors.forename: S
authors.initials: S
authors.lastname: Magari
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Sakanaka
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D002450:Cell Communication; D003713:Dendritic Cells / Q000502:physiology* / Q000648:ultrastructure; D004847:Epithelial Cells; D004848:Epithelium / Q000648:ultrastructure; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D007801:Langerhans Cells / Q000502:physiology / Q000648:ultrastructure; D008264:Macrophages / Q000502:physiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D014066:Palatine Tonsil / Q000166:cytology* / Q000648:ultrastructure; D013601:T-Lymphocytes / Q000502:physiology* / Q000648:ultrastructure