Immunohistochemical localization of HLA-DR-positive cells in unerupted and erupted normal and carious human teeth.
Class II major histocompatibility complex (MHC) antigen-expressing cells are generally associated with the early phase of the immune response. We have studied the distribution of class II-expressing cells in developing, normal, and carious human teeth to clarify when human pulp acquires an immunologic defense potential and how this reacts to dental caries. Antigen-expressing cells were identified immunohistochemically by means of HLA-DR monoclonal antibody. In the pulp of unerupted developing teeth, numerous HLA-DR-positive cells were distributed mainly in and around the odontoblast layer. In erupted teeth, HLA-DR-positive cells were located, for the most part, just beneath the odontoblast layer, with slender cytoplasmic processes extending into the layer. Superficial caries lesions caused an aggregation of HLA-DR-positive cells in dental pulp corresponding to the lesion. In teeth with deeper caries lesions, this aggregation of cells expanded to include the odontoblast layer. Also noted were HLA-DR-positive cells lying along the pulp-dentin border, with cytoplasmic processes projecting deep into the dentinal tubules, where they co-localized with odontoblast processes. These findings suggest that: (1) human dental pulp is equipped with immunologic defense potential prior to eruption; (2) in the initial stage of caries infection, an immunoresponse mediated by class-II-expressing cells is initiated in human dental pulp; and (3) HLA-DR-positive cells trespass deep into dentinal tubules as the caries lesion advances.
Department of Operative Dentistry and Endodonitics, Niigata University School of Dentistry, Japan.
N
N
Yoshiba
K
K
Yoshiba
H
H
Nakamura
M
M
Iwaku
H
H
Ozawa
D000293:Adolescent; D000328:Adult; D000938:Antigen-Presenting Cells; D001641:Bicuspid / Q000276:immunology; D003731:Dental Caries / Q000276:immunology*; D003782:Dental Pulp / Q000166:cytology / Q000276:immunology*; D003804:Dentin / Q000276:immunology*; D006684:HLA-DR Antigens / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques; D009804:Odontoblasts / Q000276:immunology; D014097:Tooth, Unerupted / Q000276:immunology
D006684:HLA-DR Antigens