Dendritic cells in the rat pituitary gland evaluated by the use of monoclonal antibodies and electron microscopy.
A detailed analysis of the difference in the localization and the immunoreactivity for various surface markers among folliculo-stellate cells, macrophages, and dendritic cells was performed using immunohistochemistry and electron microscopy of the rat pituitary gland. The folliculo-stellate cells were selectively labeled by an antiserum against S100 protein. The majority of dendritic cells were immunoreactive for the MHC class II (Ia) antigen (OX6) and/or the dendritic cell antibodies (OX62). The main population of macrophages was positive for the macrophage antibodies (ED1, ED2, and/or OX42). The cellular density of adenohypophyseal macrophages was significantly lower than that of folliculo-stellate cells and of dendritic cells. All the neurohypophyseal microglial cells were labeled with OX42, while the mAb OX6 labeled a small population of cells different from the cells identified by OX42 in the neurohypophysis. Double-immunoperoxidase staining for ED1 and OX6 revealed that positively stained cells could be classified into ED1+OX6-, ED1+OX6+, and ED1-OX6+ cells. Double staining with OX62 and OX6 mAbs showed that about 60% of the OX6+ cells were also immunolabeled with OX62 in the anterior lobe: OX62 detects a subpopulation of dendritic cells but does not recognize macrophage populations. Furthermore, double staining for S100 and OX6 resulted in no S100+ OX6+ cells. At the electron-microscopic level, reaction products for OX6 were confirmed in the cell membrane and labeled cells were distinguished from macrophages and folliculo-stellate cells by distinctive short, broad cytoplasmic processes and the rare presence of cytoplasmic organelles. Such cytological characteristics of the OX6-positive cells in the pituitary gland are similar to dendritic cells. Our results suggest that resident dendritic cells and folliculo-stellate cells are two different main components of interstitial cells in the pituitary gland.
Sato
T
T
Department of Anatomy, School of Dental Medicine, Tsurumi University, Yokohama, Japan. m00777@simail.ne.jp
Inoue
K
K
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology; D003713:Dendritic Cells / Q000737:chemistry / Q000166:cytology / Q000276:immunology / Q000648:ultrastructure*; D005260:Female; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008264:Macrophages / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D008297:Male; D010641:Phenotype; D010902:Pituitary Gland / Q000166:cytology* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface