title: Immunohistochemical demonstration of T cell subsets and accessory cells in oral lichen planus.
abstract: The nature and distribution of mononuclear cells in 30 non-ulcerated lesions of oral lichen planus (OLP) was investigated, using an immunoperoxidase technique. Most of the infiltrating cells consisted of a mixture of Leu 2a+ and Leu 3a+/3b+ T cells present in the stroma. This study proved histometrically that the emigration of lymphocytes through subepithelial vessels was not selective for major subsets of T cells and subsequent migration to the epithelium was predominant in suppressor/cytotoxic T cell infiltration. HLA-DR+/DQ+ monocyte/macrophage and Langerhans cells formed a relatively minor component of the cellular infiltrates, whereas a considerable number of T cells expressed the MHC antigens. Also, the keratinocytes of the epithelium expressed only DR antigens. These results support the concept that LP is associated with lymphokine-generated inflammation induced by helper/inducer T cells or activated T cells which would include direct basal cell damage or local immunosuppression by suppressor/cytotoxic T cells. Furthermore, this study suggests that monocytes/macrophages and Langerhans cells played a role in antigen presentation, and also that keratinocytes may possess a similar function.
mesh_terms: D000328:Adult; D000368:Aged; D002452:Cell Count; D005260:Female; D006801:Humans; D007801:Langerhans Cells / Q000473:pathology; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000473:pathology; D008010:Lichen Planus / Q000276:immunology / Q000473:pathology*; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000473:pathology; D009059:Mouth Diseases / Q000276:immunology / Q000473:pathology*; D009061:Mouth Mucosa / Q000276:immunology / Q000473:pathology*; D013601:T-Lymphocytes / Q000145:classification*