Localization and density of myeloid leucocytes in the periodontal ligament of normal rat molars.
The phenotypic distribution and density of macrophage-associated antigen-expressing cells in the periodontal ligament (PDL) of normal rat mandibular first molars was evaluated by immunohistochemistry, and an attempt made to identify dendritic cells (DCs) by immunoelectron microscopy. Cells immunopositive to ED1 (a general macrophage marker) were widely distributed throughout the PDL and were most common around blood vessels. A small number of T lymphocytes and OX62 (anti-veiled cells and gammadelta T cells)-positive DC-like cells were also found. The relative density of cells immunopositive to ED9 (CD14), OX42 (CD11b), OX6 (anti-class II MHC molecules), ED2 (anti-tissue-resident macrophages), 8A2 (CD11c) and WT.1 (CD11a) varied in the mesial, distal and periapical regions of the distal root and the furcal region. This finding suggests that there are several subpopulations of ED1-positive cells which express various combinations of these markers. Immunoelectron microscopy revealed that a small, but distinct, subpopulation of ED1- and OX6-positive cells did have a DC-like ultrastructure, although the majority of these cells were identified as macrophages. The DC-like cells were characterized by poorly developed lysosomal structures and an absence of phagocytic vesicles. It was concluded that the normal rat PDL is equipped with heterogeneous populations of macrophages with regional variations in density. The DC-like cells may function as antigen-presenting cells.
Kan
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Pulp Biology and Endodontics, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, 113-8549, Tokyo, Japan.
Okiji
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T
Kaneko
T
T
Suda
H
H
D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D018845:CD11 Antigens / Q000032:analysis; D002452:Cell Count; D003713:Dendritic Cells / Q000166:cytology; D005856:Germ-Free Life; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007150:Immunohistochemistry; D007958:Leukocyte Count; D007962:Leukocytes / Q000166:cytology*; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008247:Lysosomes / Q000648:ultrastructure; D016177:Macrophage-1 Antigen / Q000032:analysis; D008264:Macrophages / Q000166:cytology*; D008297:Male; D016253:Microscopy, Immunoelectron; D008963:Molar; D010486:Periapical Tissue / Q000166:cytology; D010513:Periodontal Ligament / Q000166:cytology*; D010587:Phagocytosis; D010641:Phenotype; D051381:Rats; D017208:Rats, Wistar; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D013601:T-Lymphocytes / Q000166:cytology; D014092:Tooth Root / Q000166:cytology; D014617:Vacuoles / Q000648:ultrastructure; D000097382:CD68 Molecule
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018845:CD11 Antigens; D000949:Histocompatibility Antigens Class II; D018950:Lipopolysaccharide Receptors; D016177:Macrophage-1 Antigen; D016692:Receptors, Antigen, T-Cell, gamma-delta; C067980:CD68 antigen, human; D000097382:CD68 Molecule