Immunoelectron microscopic study of distribution of T cell subsets in oral lichen planus

Abstract

– Monoclonal anti‐CD4, anti‐CD8, and anti‐GD18 antibodies were applied in avidinbiotin‐peroxidase complex staining using a pre‐embedding immunoelectron microscopy technique. Although most of the local T cells in situ were of CD4+ subtype, local CD8+ cells generally had a lower nucleus/cytoplasm ratio and contained more cell organelles than CD4+ cells. This suggests a local activation of CD8+ subpopulation, rather than activation of the numerically predominant CD4+ cells. Topographical analysis disclosed that all lymphocytes, regardless of location, were CD18+ and that most of the CD8 + cells were located subbasally and intraepithelially, whereas CD4+ cells often occurred in small clusters deeper down in the subepithelial lymphocyte‐rich band. Furthermore, CD8+ cells were often in close contact with macrophages, whereas CD4+ cells were in some instances in direct contact with plasma cells. This indicates that CD4+ cells may be involved in T cell‐dependent B cell‐mediated immunoglobulin synthesis, whereas CD8+ cytotoxic lymphocytes and tissue macrophages may be involved in the local pathogenetic process leading to basement membrane alterations.

Brn2 Is a Transcription Factor Regulating Keratinocyte Differentiation with a Possible Role in the Pathogenesis of Lichen Planus

“…Lichen planus is a T-cell-mediated chronic inflammatory disease of unknown etiology. The lymphocytic infiltrates in lichen planus are composed almost exclusively of T-cells, and the majority of T-cells are activated CD3 + and CD8 + lymphocytes [18]–[21]. Consistent with this notion, CD3 positive T cells were infiltrated in the skin of the Brn2 adenovirus injected rat (Figure 6B).…”

Oral lichen planus: an update on its pathogenesis

“…The degeneration of basal keratinocytes observed in LP is attributed to cytotoxic CD8+ T lymphocytes, which represent the main component of the infiltrate located within the epidermis and adjacent to damaged keratinocytes . As the disease progresses, a gradual accumulation of CD8+ T lymphocytes occurs …”

The Pathogenesis of Oral Lichen Planus

“…The lymphocytic infiltrate in OLP is composed almost exclusively of T-cells, and the majority of T-cells within the epithelium and adjacent to damaged basal keratinocytes are activated CD8 + lymphocytes (Matthews et al, 1984;Kilpi, 1987Kilpi, , 1988Jungell et al, 1989b). In our recent studies, the majority of subepithelial and intra-epithelial lymphocytes in OLP were CD8 + (Khan et al, 2001, submitted).…”