Antigen-presenting cells in human radicular granulomas.
Substantial numbers of dendritic cells have been detected in radicular granulomas. To test the hypothesis that local antigen presentation from dendritic cells to T-cells is involved critically in immunological responses within radicular granulomas, we compared characteristics of dendritic cells and macrophages by morphological and biological analyses. Under light microscopy, HLA-DR+ and CD68+ cells showed diverse profiles, including dendritic-shaped cells. Transmission electron microscopy revealed that HLA-DR+ dendritic cells, with long cytoplasmic processes and lacking distinct phagosomes, were concentrated in the lymphocyte-rich area. HLA-DR alpha-chain, CD83, and CD86 mRNAs from HLA-DR+ dendritic cells, and CD28 mRNA from CD28+ T-cells were up-regulated in lymphocyte-rich area. Scanning electron microscopy demonstrated that the density of gold particles on dendritic cells was higher than that on HLA-DR+ macrophages. These results suggest that dendritic cells in radicular granulomas are associated with local defense reactions as stronger antigen-presenting cells, as compared with macrophages.
Kaneko
T
T
Pulp Biology and Endodontics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. tomoendo@tmd.ac.jp
Okiji
T
T
Kaneko
R
R
Nör
J E
JE
Suda
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H
D017951:Antigen Presentation; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D051940:B7-2 Antigen / Q000032:analysis; D018106:CD28 Antigens; D003713:Dendritic Cells / Q000276:immunology* / Q000648:ultrastructure; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D007150:Immunohistochemistry; D008264:Macrophages / Q000276:immunology; D008562:Membrane Glycoproteins / Q000032:analysis; D008854:Microscopy, Electron; D010484:Periapical Granuloma / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D013601:T-Lymphocytes / Q000276:immunology; D000097802:CD83 Antigen; D000097382:CD68 Molecule
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D051940:B7-2 Antigen; D018106:CD28 Antigens; D006684:HLA-DR Antigens; D007136:Immunoglobulins; D008562:Membrane Glycoproteins; D000097802:CD83 Antigen; C067980:CD68 antigen, human; D000097382:CD68 Molecule